Home » Public Forums » GMCnet » 700 trouble free miles, with a few quirks
| 700 trouble free miles, with a few quirks [message #142372] |
Sun, 04 September 2011 14:20  |
Andrew
Messages: 213
Registered: April 2011
Location: Connecticut
Karma: 0
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Senior Member |
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700 trouble free miles, a new personal record. 1700 miles since the beginning of July, and a few thousand more to go on this trip. We are in Boston now and will be heading to the west coast soon.
A few quirks I've noticed along the way, wondering if anyone has any thoughts:
1. I feel a bit of wander, I think from the rear. The front end doesn't seem to pull, and it's much more noticeable while towing a 3200# car. I've checked ride height and tire inflation (frequently), and read Jerry Work's alignment guide. I replaced all of my steel wheels with new Eagles, which helped a lot but didn't fix it completely. Next step is a six wheel alignment at a shop that knows what they're doing, right? Any recommendations in the Boston/southern New England area?
2. My oil pressure gauge is bouncing around with engine speed. I know this is normal to some extent, but it bothers me that it reads almost zero at low idle. Highway speeds bring it up to slightly low of half way. I've checked the oil level (frequently), and it seems fine, I don't entirely trust my dipstick because it's a bit bendy and I'm never sure it's reaching all the way into the sump, but I added a quart of oil and saw the level rise as expected. I think I'm now a quarter or half quart high of full. No change in gauge behavior. Is my sender bad?
3. My speedometer reads consistently low at highway speeds, by 7-10%. It's much closer at slower speeds. I measured my odometer against mile markers, and it's 0-5% low, measured over several 20 mile stretches. Does that indicate worn gears? Do these speedos get rebuilt?
4. (I saved the best for last) I am having some kind of fuel delivery problem, still after replacing the fuel pump. Freshly cleaned tanks, new lines, new filters, but:
- she's sometimes a little hard to start still..several long pumps of the accelerator will get it after sitting for a day or two. Several more if longer. She often cuts out right after startup unless I hold the accelerator down a bit as soon as she catches (after ten seconds or so, I can let go and she falls into the normal startup elevated idle, and holds for a few mins until I tap the accelerator again and she drops to low idle...that part is normal, right?).
- she will often hesitate under heavy acceleration (on ramps, hills). Never misses more than a fraction of a second, but always concerns me, because:
- she occasionally stalls, usually when coming down to idle from higher speeds. It happens with a full tank, with a half tank, when pointed up hill, and when pointed down. Most noticeable in traffic, like when hitting a slowdown on a highway. So far she always starts right back up, but worries me every time.
- my wife followed behind in the car for a few hundred miles. A few times, she saw what she called a "backfire". I didn't feel it as such, but she described it as a puff of white "smoke". I did feel some roughness, but it was hard to differentiate between the hesitation, a normally loud cockpit, bumpy highway road, etc.
I'm thinking I need to adjust the idle, and hunt down any possible ingress of air into the (wrong part of the) carb. Am I on the right path? Any other ideas? Could the white "smoke" be a fuel impurity issue?
Thanks for your help and advice!
1973 Sequoia 260 (since 2011)
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| Re: [GMCnet] 700 trouble free miles, with a few quirks [message #142376 is a reply to message #142372] |
Sun, 04 September 2011 14:56  |
James Hupy
Messages: 6806
Registered: May 2010
Karma: -62
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Senior Member |
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White smoke can be an indicator of water turning to steam, or oil
consumption. Black smoke is more than likely too much fuel relative to the
amount of air. It might be helpful to know the year of your coach and the
wheel, tire, air pressure combination. Check for worn bogie pins, or low
tire pressures, or excess axial play in the bogie arms, (adjustable) with
regards to wander caused by rear suspension. If it emanates from the front
end, the usual culprits are worn tie rod ends, or lower ball joints, with
control arm bushings and/or alignment issues.
As to the oil pressure fluctuations, causes can be poor reading electrical
gages, worn oil pump, worn engine bearings, too low a viscosity oil, The
manual for the 455 says hot idle oil pressure is 15 psi, running at highway
speed 35 psi or so. An accurate mechanical gage might confirm if you have an
electrical gage problem. They are notoriously inaccurate.
As to the fuel/carb problem. The symptoms that you describe all point to a
vacuum leak combined with a loose center screw in the throttle body to float
bowl . Carb has to come off to tighten it. If left loose, it will warp the
float bowl and/or throttle body allowing the carb to leak down overnight
causing the morning hardstart condition. Engine dies on quick decelleration
sounds like low idle speed setting, or perhaps low float setting in the
carb. Which carb you have depends on year and emissions package. Cal vs
49state etc. 455 vs 403. Helps to know these things when diagnosing problems
longrange. The more info you provide, the better it is for us trying to help
you figure it out.
Jim Hupy
Salem, OR
78 GMC Royale 403
On Sun, Sep 4, 2011 at 12:20 PM, Andrew <reynhout@quesera.com> wrote:
>
>
> 700 trouble free miles, a new personal record. 1700 miles since the
> beginning of July, and a few thousand more to go on this trip. We are in
> Boston now and will be heading to the west coast soon.
>
> A few quirks I've noticed along the way, wondering if anyone has any
> thoughts:
>
> 1. I feel a bit of wander, I think from the rear. The front end doesn't
> seem to pull, and it's much more noticeable while towing a 3200# car. I've
> checked ride height and tire inflation (frequently), and read Jerry Work's
> alignment guide. I replaced all of my steel wheels with new Eagles, which
> helped a lot but didn't fix it completely. Next step is a six wheel
> alignment at a shop that knows what they're doing, right? Any
> recommendations in the Boston/southern New England area?
>
> 2. My oil pressure gauge is bouncing around with engine speed. I know this
> is normal to some extent, but it bothers me that it reads almost zero at low
> idle. Highway speeds bring it up to slightly low of half way. I've checked
> the oil level (frequently), and it seems fine, I don't entirely trust my
> dipstick because it's a bit bendy and I'm never sure it's reaching all the
> way into the sump, but I added a quart of oil and saw the level rise as
> expected. I think I'm now a quarter or half quart high of full. No change in
> gauge behavior. Is my sender bad?
>
> 3. My speedometer reads consistently low at highway speeds, by 7-10%. It's
> much closer at slower speeds. I measured my odometer against mile markers,
> and it's 0-5% low, measured over several 20 mile stretches. Does that
> indicate worn gears? Do these speedos get rebuilt?
>
> 4. (I saved the best for last) I am having some kind of fuel delivery
> problem, still after replacing the fuel pump. Freshly cleaned tanks, new
> lines, new filters, but:
>
> - she's sometimes a little hard to start still..several long pumps of the
> accelerator will get it after sitting for a day or two. Several more if
> longer. She often cuts out right after startup unless I hold the accelerator
> down a bit as soon as she catches (after ten seconds or so, I can let go and
> she falls into the normal startup elevated idle, and holds for a few mins
> until I tap the accelerator again and she drops to low idle...that part is
> normal, right?).
>
> - she will often hesitate under heavy acceleration (on ramps, hills). Never
> misses more than a fraction of a second, but always concerns me, because:
>
> - she occasionally stalls, usually when coming down to idle from higher
> speeds. It happens with a full tank, with a half tank, when pointed up hill,
> and when pointed down. Most noticeable in traffic, like when hitting a
> slowdown on a highway. So far she always starts right back up, but worries
> me every time.
>
> - my wife followed behind in the car for a few hundred miles. A few times,
> she saw what she called a "backfire". I didn't feel it as such, but she
> described it as a puff of white "smoke". I did feel some roughness, but it
> was hard to differentiate between the hesitation, a normally loud cockpit,
> bumpy highway road, etc.
>
> I'm thinking I need to adjust the idle, and hunt down any possible ingress
> of air into the (wrong part of the) carb. Am I on the right path? Any other
> ideas? Could the white "smoke" be a fuel impurity issue?
>
> Thanks for your help and advice!
> --
> 1973 Sequoia 260 (since 2011)
> In-transit, westward
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
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| Re: [GMCnet] 700 trouble free miles, with a few quirks [message #142399 is a reply to message #142372] |
Sun, 04 September 2011 21:06 |
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USAussie
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
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Senior Member |
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Andrew,
Glad to hear your trip went well and that you are enjoying your GMC.
Re your questions / concerns:
1) You could have an alignment done but unless all the suspension (front & rear) and steering components are in good shape you're
wasting money.
You can use this procedure to check the steering component by component:
http://www.gmceast.com/technical/Mueller_Steering_Inspection_Guide.pdf
There is one caveat about this procedure, the steps to check the tie rod ends WILL NOT WORK! To check them the GMC must have all six
wheels on the ground and the steering wheel pointed straight ahead before it is moved from side to side. I have not gotten a chance
to re-write it yet.
Here's a link to the Local GMC Service Provider Recommendations:
http://www.bdub.net/GMCServiceComments.pdf
Unfortunately the only GMC shops in the New England area are in New Hampshire.
I note you stated you're heading west, you could contact:
Ken Frey in Quakertown, PA: http://www.kenlfreyautorepair.com/home
Note: Ken and Janet are currently on a trip to Alaska and I'm not sure when they'll get back to Quakertown.
or
Tom Hampton in Marysville, OH: http://www.grandviewmotorhome.com/
I ga-ron-tee they both KNOW what they are doing and will fix what needs to be fixed and NOT rip you off!
2) The OEM oil pressure gage leaves a bit to be desired, I would suggest you install a "real" gage. I installed a set of Nitrous
gages from Harbor Freight:
http://tinyurl.com/4x7p6gp
Yes, they are cheap, however, I also have a Digi-Panel and the readings of both units agree; give or take a bit.
http://www.appliedgmc.com/prod.itml/icOid/496
You could install a mechanical gage like this:
http://www.summitracing.com/parts/ATM-2332/RepairParts/?prefilter=1
3) Assuming that when you installed the Eagle wheels you fitted 225x75-16 tires the speedo is off. The speedo gears are nylon and
probably are not the problem. I don't know what the manufacturing tolerance was but AFAIK most speedos can be calibrated.
4) When you shut down a GMC with a hot engine the heat in the manifold will boil the fuel out of the carb. When you go to restart it
you will have to fill the fuel bowls. If you attend a GMC rally you will hear GMC after GMC crank and crank before they fire up.
Sounds like your carb could stand a re-build, if you decide to have it done Dick Paterson is DA MAN!
http://www.springfield-ignition.com/carb.htm
Also, you could have vapor lock problems.
Regards,
Rob M.
-----Original Message-----
From: Andrew
700 trouble free miles, a new personal record. 1700 miles since the beginning of July, and a few thousand more to go on this trip.
We are in Boston now and will be heading to the west coast soon.
A few quirks I've noticed along the way, wondering if anyone has any thoughts:
1. I feel a bit of wander, I think from the rear. The front end doesn't seem to pull, and it's much more noticeable while towing a
3200# car. I've checked ride height and tire inflation (frequently), and read Jerry Work's alignment guide. I replaced all of my
steel wheels with new Eagles, which helped a lot but didn't fix it completely. Next step is a six wheel alignment at a shop that
knows what they're doing, right? Any recommendations in the Boston/southern New England area?
2. My oil pressure gauge is bouncing around with engine speed. I know this is normal to some extent, but it bothers me that it reads
almost zero at low idle. Highway speeds bring it up to slightly low of half way. I've checked the oil level (frequently), and it
seems fine, I don't entirely trust my dipstick because it's a bit bendy and I'm never sure it's reaching all the way into the sump,
but I added a quart of oil and saw the level rise as expected. I think I'm now a quarter or half quart high of full. No change in
gauge behavior. Is my sender bad?
3. My speedometer reads consistently low at highway speeds, by 7-10%. It's much closer at slower speeds. I measured my odometer
against mile markers, and it's 0-5% low, measured over several 20 mile stretches. Does that indicate worn gears? Do these speedos
get rebuilt?
4. (I saved the best for last) I am having some kind of fuel delivery problem, still after replacing the fuel pump. Freshly cleaned
tanks, new lines, new filters, but:
- she's sometimes a little hard to start still..several long pumps of the accelerator will get it after sitting for a day or two.
Several more if longer. She often cuts out right after startup unless I hold the accelerator down a bit as soon as she catches
(after ten seconds or so, I can let go and she falls into the normal startup elevated idle, and holds for a few mins until I tap the
accelerator again and she drops to low idle...that part is normal, right?).
- she will often hesitate under heavy acceleration (on ramps, hills). Never misses more than a fraction of a second, but always
concerns me, because:
- she occasionally stalls, usually when coming down to idle from higher speeds. It happens with a full tank, with a half tank, when
pointed up hill, and when pointed down. Most noticeable in traffic, like when hitting a slowdown on a highway. So far she always
starts right back up, but worries me every time.
- my wife followed behind in the car for a few hundred miles. A few times, she saw what she called a "backfire". I didn't feel it as
such, but she described it as a puff of white "smoke". I did feel some roughness, but it was hard to differentiate between the
hesitation, a normally loud cockpit, bumpy highway road, etc.
I'm thinking I need to adjust the idle, and hunt down any possible ingress of air into the (wrong part of the) carb. Am I on the
right path? Any other ideas? Could the white "smoke" be a fuel impurity issue?
Thanks for your help and advice!
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
Regards,
Rob M. (USAussie)
The Pedantic Mechanic
Sydney, Australia
'75 Avion - AUS - The Blue Streak TZE365V100428
'75 Avion - USA - Double Trouble TZE365V100426
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| Re: 700 trouble free miles, with a few quirks [message #142419 is a reply to message #142372] |
Mon, 05 September 2011 05:50 |
John Sharpe
Messages: 489
Registered: February 2006
Location: Texas
Karma: 1
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Senior Member |
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| Quote: |
1. I feel a bit of wander, I think from the rear. The front end doesn't seem to pull, and it's much more noticeable while towing a
3200# car. I've checked ride height and tire inflation (frequently), and read Jerry Work's alignment guide. I replaced all of my
steel wheels with new Eagles, which helped a lot but didn't fix it completely. Next step is a six wheel alignment at a shop that
knows what they're doing, right? Any recommendations in the Boston/southern New England area? | Quote: |
Part or all of your wander is your toad. I observed my HHR through the rear window when someone else was driving. I have a Blue OX tow bar but the toad continues to drift from side to side. This tracking of the toad causes the rear to sway ever so slightly. If you have worn parts this action would exacerbate the problem. This action is particularly noticeable when making a curve. I can feel the bump in the rear when the toad adjusts to make the turn. That action does not occur without the toad.
|
2. My oil pressure gauge is bouncing around with engine speed. I know this is normal to some extent, but it bothers me that it reads
almost zero at low idle. Highway speeds bring it up to slightly low of half way. I've checked the oil level (frequently), and it
seems fine, I don't entirely trust my dipstick because it's a bit bendy and I'm never sure it's reaching all the way into the sump,
but I added a quart of oil and saw the level rise as expected. I think I'm now a quarter or half quart high of full. No change in
gauge behavior. Is my sender bad?| Quote: |
Are you running 10W30? If you have a seasoned engine I would recommend that you run a straight weight oil like Delo 400 40W DO NOT use Delo 400 LE
|
3. My speedometer reads consistently low at highway speeds, by 7-10%. It's much closer at slower speeds. I measured my odometer
against mile markers, and it's 0-5% low, measured over several 20 mile stretches. Does that indicate worn gears? Do these speedos
get rebuilt?| Quote: |
Yes or just compensate
|
4. (I saved the best for last) I am having some kind of fuel delivery problem, still after replacing the fuel pump. Freshly cleaned
tanks, new lines, new filters, but:
- she's sometimes a little hard to start still..several long pumps of the accelerator will get it after sitting for a day or two.
Several more if longer. She often cuts out right after startup unless I hold the accelerator down a bit as soon as she catches
(after ten seconds or so, I can let go and she falls into the normal startup elevated idle, and holds for a few mins until I tap the
accelerator again and she drops to low idle...that part is normal, right?).| Quote: |
Probably the carburetor. See Dick Patterson
|
- she will often hesitate under heavy acceleration (on ramps, hills). Never misses more than a fraction of a second, but always
concerns me, because:| Quote: |
Probably the carburetor. See Dick Patterson
|
- she occasionally stalls, usually when coming down to idle from higher speeds. It happens with a full tank, with a half tank, when
pointed up hill, and when pointed down. Most noticeable in traffic, like when hitting a slowdown on a highway. So far she always
starts right back up, but worries me every time.| Quote: |
Probably the carburetor. See Dick Patterson
|
- my wife followed behind in the car for a few hundred miles. A few times, she saw what she called a "backfire". I didn't feel it as
such, but she described it as a puff of white "smoke". I did feel some roughness, but it was hard to differentiate between the
hesitation, a normally loud cockpit, bumpy highway road, etc.| Quote: |
Probably the carburetor. See Dick Patterson
|
I'm thinking I need to adjust the idle, and hunt down any possible ingress of air into the (wrong part of the) carb. Am I on the
right path? Any other ideas? Could the white "smoke" be a fuel impurity issue?| Quote: |
Probably the carburetor. See Dick Patterson
|
Thanks for your help and advice!
|
John Sharpe
Humble,TX
'78 Eleganza TBI
'89 Spectrum 2000 MPI V-10
'40 Ford Panel Delivery TPI
johnasharpe@gmail.com
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| Re: 700 trouble free miles, with a few quirks [message #142423 is a reply to message #142372] |
Mon, 05 September 2011 06:59 |
chasingsummer
Messages: 434
Registered: May 2011
Location: asheboro, nc
Karma: 0
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Senior Member |
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Andrew
i too noticed my speedo is off approx the same as yours. i am running the orginal wheels, if iunderstand correctly either have speedo shop repair or adjust. i choose the cheep way out of living with it.
my oil pressure guage does not bounce around, i am making sure i run the proper weight of oil. i also run a little lucas oil treatmnent. i dont know if it really helps or not, but it makes me feel better. the same with the sea foam in gas can. usually one can for every 3rd or 4th fill up.
i have no expereince in towing with my gmc, but from towing a boat before whan my tongue weight was wrong i felt similar issues.
your carb needs to be rebuilt. (would a pin hole in a float give similar problem? ) i rebuilt a quad carb many years back from a 78 buick with the 403. i remember it took me approx one hour to get off car, but then it was hours and hours later i got it right. i took it apart then took a break. dont do that, if you stay with it it can be done. but having someone who has done many of them will be better. all the little secrets and etc that they know. I dont know Dick Paterson, but his name comes up here every time carbs are mentioned.
hang in there, i for one are pulling for you and your trip to be a safe, and enjoyable one. you already know you will never forget it.
brian
brian
asheboro, nc
75 eleganza, 74 build
119k miles and counting,
DOG HOUSE
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| Re: 700 trouble free miles, with a few quirks [message #142447 is a reply to message #142419] |
Mon, 05 September 2011 10:30 |
Carl S.
Messages: 4186
Registered: January 2009
Location: Tucson, AZ.
Karma: 13
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Senior Member |
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Not to go against the grain here, and we all know Dick Patterson is the big cheese when it comes to carbs and distributors, but Chr$ seems to have had good luck with a Jim Bounds carburetor rebuild. Just a slightly less expensive alternative.
Carl Stouffer
'75 ex Palm Beach
Tucson, AZ.
Chuck Aulgur Reaction Arm Disc Brakes, Quadrabags, 3.70 LSD final drive, Lenzi knuckles/hubs, Dodge Truck 16" X 8" front wheels, Rear American Eagles, Solar battery charging. GMCSJ and GMCMI member
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| Re: [GMCnet] 700 trouble free miles, with a few quirks [message #142485 is a reply to message #142447] |
Mon, 05 September 2011 17:00 |
jade
Messages: 163
Registered: August 2009
Karma: 0
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Senior Member |
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Carl;
I've had both Jim B. & Dick Patterson do each of my carbs on my 73's, & have
had good luck with both.
Not much difference in price.
Just my opinion.
JADE
73 23' ?? 73 26' Painted Desert
Ajo, AZ
KC7QGC
----- Original Message -----
From: "Carl Stouffer" <carljr3b@yahoo.com>
To: <gmclist@temp.gmcnet.org>
Sent: Monday, September 05, 2011 8:30 AM
Subject: Re: [GMCnet] 700 trouble free miles, with a few quirks
>
>
> Not to go against the grain here, and we all know Dick Patterson is the
> big cheese when it comes to carbs and distributors, but Chr$ seems to have
> had good luck with a Jim Bounds carburetor rebuild. Just a slightly less
> expensive alternative.
> --
> Carl S.
> '75 ex Palm Beach
> Tucson, AZ.
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
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| Re: 700 trouble free miles, with a few quirks [message #142536 is a reply to message #142372] |
Mon, 05 September 2011 22:27 |
Andrew
Messages: 213
Registered: April 2011
Location: Connecticut
Karma: 0
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Senior Member |
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Re: speedo/odo discrepancies.. I wondered if the new tire size would have an effect, but the comments I read in other threads suggested that it would be very small.
If it's just the tires, shouldn't the speedo and odo variances be the same percentages? I'm seeing the speedo almost 10% low all the time at highway speed, but the odo is nearly dead on at times, and just a couple percent low others.
The fact that they aren't in obvious relation is why I guessed that something was up in the internals of the speedo. I would have expected the odo to lag the speedo, but that might just be because they don't work the way I imagine they do.
The reason this is an incredibly important problem to solve is that otherwise, my mpg math is a total fiction.
(Kidding. I know that the full precision result is "about eight-point-expensive".)
One positive side effect of having this trip be so delayed is that gas prices have dropped a fair bit in the last couple months.
1973 Sequoia 260 (since 2011)
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| Re: 700 trouble free miles, with a few quirks [message #142540 is a reply to message #142536] |
Mon, 05 September 2011 22:38 |
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mike miller
Messages: 3576
Registered: February 2004
Location: Hillsboro, Oregon
Karma: 0
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Senior Member |
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| Andrew wrote on Mon, 05 September 2011 20:27 |
...
If it's just the tires, shouldn't the speedo and odo variances be the same percentages? I'm seeing the speedo almost 10% low all the time at highway speed, but the odo is nearly dead on at times, and just a couple percent low others. ...
|
70's and before the accuracy of the "speedo" wasn't THAT important. The long term reliablity of said "speedo" was even less important.
now, 30 some-odd years later... most of these "speedos" are not much use.
Use the GPS for speed and mileage calculations.
-- wasn't "speedo" a swim suit? -- even so, statement stands. 
Mike Miller -- Hillsboro, OR -- on the Black list
(#2)`78 23' Birchaven Rear Bath -- (#3)`77 23' Birchaven Side Bath
More Sidekicks than GMC's and a late model Malibu called 'Boo'
http://m000035.blogspot.com
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| Re: [GMCnet] 700 trouble free miles, with a few quirks [message #142541 is a reply to message #142536] |
Mon, 05 September 2011 22:43 |
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USAussie
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma: 6
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Senior Member |
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Andrew,
Here's a link that explains how a speedo works:
http://www.explainthatstuff.com/how-speedometer-works.html
Scroll down to "How Speedometers Work" and you see that the spring tension sets how far the needle moves.
Adjusting the spring tension calibrates the speedo.
The Odometer works like this:
http://wiki.answers.com/Q/How_odometer_works
Regards,
Rob M.
-----Original Message-----
From: gmclist-bounces@temp.gmcnet.org [mailto:gmclist-bounces@temp.gmcnet.org] On Behalf Of Andrew
Sent: Tuesday, 6 September 2011 1:27 PM
To: gmclist@temp.gmcnet.org
Subject: Re: [GMCnet] 700 trouble free miles, with a few quirks
Re: speedo/odo discrepancies.. I wondered if the new tire size would have an effect, but the comments I read in other threads
suggested that it would be very small.
If it's just the tires, shouldn't the speedo and odo variances be the same percentages? I'm seeing the speedo almost 10% low all the
time at highway speed, but the odo is nearly dead on at times, and just a couple percent low others.
The fact that they aren't in obvious relation is why I guessed that something was up in the internals of the speedo. I would have
expected the odo to lag the speedo, but that might just be because they don't work the way I imagine they do.
The reason this is an incredibly important problem to solve is that otherwise, my mpg math is a total fiction.
(Kidding. I know that the full precision result is "about eight-point-expensive".)
One positive side effect of having this trip be so delayed is that gas prices have dropped a fair bit in the last couple months.
--
1973 Sequoia 260 (since 2011)
In-transit, westward
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
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Regards,
Rob M. (USAussie)
The Pedantic Mechanic
Sydney, Australia
'75 Avion - AUS - The Blue Streak TZE365V100428
'75 Avion - USA - Double Trouble TZE365V100426
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| Re: 700 trouble free miles, with a few quirks [message #142542 is a reply to message #142372] |
Mon, 05 September 2011 22:49 |
Andrew
Messages: 213
Registered: April 2011
Location: Connecticut
Karma: 0
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Senior Member |
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Re: oil pressure gauge fluctuations and reading very low at warm idle...
I'm running straight SAE 30 dino juice, because that's what Southland MHC recommended, quite strongly, and because they filled her with it while she was there for extensive work. Might that weight explain the dramatic pressure fluctuations when warm?
I'm reconsidering the oil for next change, and I've read many of the oil threads in the archives. I'll be heading into cooler weather soon, as well. The engine is well-seasoned (79k miles).
I will hook up a mechanical gauge to see if my dash gauge is flaky. With all of the major surprises I've had in the last few months, I don't want to add "new engine" to the list, so I might be giving the gauge more attention than it deserves.
1973 Sequoia 260 (since 2011)
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| Re: 700 trouble free miles, with a few quirks [message #142545 is a reply to message #142372] |
Mon, 05 September 2011 23:22 |
Andrew
Messages: 213
Registered: April 2011
Location: Connecticut
Karma: 0
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Senior Member |
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Re: wander, I think from the rear...
I should have mentioned that the entire rear suspension was replaced by Southland MHC. Subsequently, the coach has been towed from the front for about 100 miles. I think the wander got worse after that tow, although I also switched from a tow dolly to a flat-tow setup at the same time.
Replacing the steel wheels helped tremendously. I transferred my new tires (800 miles) from the 16" steel wheels to the new Eagles. The new rims made the difference between consistently unsafe and merely occasionally surprising. I have experience towing much larger and heavier things than a Honda CR-V, so I want to believe that this is a correctable problem.
This issue is a minor wander when not towing, but with the car behind it turns into a fairly significant wag that requires active dampening. It was constant and exhausting before the new wheels. Now it's frequent and usually quickly caught, but I don't think anyone would tow if this was normal.
Jim, it's a 1973, newish 225/75 R16 tires, load range E, inflated to 80psi. Rear suspension completely replaced a few months ago. Ride height at OM standard. Southland air bags. Road master tow bar and bracket.
John, I really hope it isn't the tow bar. That would be a big disappointment. I am uncomfortable asking anyone else to drive it under these circumstances, but I'll find a way to get a look at the towing gear in action.
Thanks for the suggestions, guys. This one is headache inducing, quite literally.
1973 Sequoia 260 (since 2011)
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| Re: 700 trouble free miles, with a few quirks [message #142546 is a reply to message #142372] |
Mon, 05 September 2011 23:44 |
Andrew
Messages: 213
Registered: April 2011
Location: Connecticut
Karma: 0
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Senior Member |
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Re: fuel delivery and various hiccups...
It's good to learn that the long cranking is semi-normal and not necessarily indicative of a current of future issue.
The stalling is definitely the most concerning, so I'll start there. If I can get that one with an idle adjustment, without rebuilding the whole carb, I'll consider myself fortunate. But I'm sure a carb rebuild is in my not-so-distant future as well.
It's a 1973 coach, so 455ci of course. The original purchase was in Washington state, so 49-state emissions I presume. Not sure how to check that visually.
Thanks for all the help. In case it wasn't clear, we are having a fun trip. Our fridge is about to expire, and there's a freshwater leak in the bathroom, and ... well, lots of other things, but we are hardy folks. By the time we reach the west coast, all she'll need is paint..!
1973 Sequoia 260 (since 2011)
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| Re: [GMCnet] 700 trouble free miles, with a few quirks [message #142553 is a reply to message #142545] |
Tue, 06 September 2011 00:14 |
mtnman111
Messages: 20
Registered: August 2004
Karma: 0
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Junior Member |
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Andrew, You're running way too much air press in your tires, 80 is for max load, you're nowhere near that heavy. i run 55 to 60 psi all round. i'll bet if you drop the press you'll have a better handling coach. Good luck, Larry Conley
--- On Mon, 9/5/11, Andrew <reynhout@quesera.com> wrote:
> From: Andrew <reynhout@quesera.com>
> Subject: Re: [GMCnet] 700 trouble free miles, with a few quirks
> To: gmclist@temp.gmcnet.org
> Date: Monday, September 5, 2011, 9:22 PM
>
>
> Re: wander, I think from the rear...
>
> I should have mentioned that the entire rear suspension was
> replaced by Southland MHC. Subsequently, the coach has been
> towed from the front for about 100 miles. I think the wander
> got worse after that tow, although I also switched from a
> tow dolly to a flat-tow setup at the same time.
>
> Replacing the steel wheels helped tremendously. I
> transferred my new tires (800 miles) from the 16" steel
> wheels to the new Eagles. The new rims made the difference
> between consistently unsafe and merely occasionally
> surprising. I have experience towing much larger and heavier
> things than a Honda CR-V, so I want to believe that this is
> a correctable problem.
>
> This issue is a minor wander when not towing, but with the
> car behind it turns into a fairly significant wag that
> requires active dampening. It was constant and exhausting
> before the new wheels. Now it's frequent and usually quickly
> caught, but I don't think anyone would tow if this was
> normal.
>
> Jim, it's a 1973, newish 225/75 R16 tires, load range E,
> inflated to 80psi. Rear suspension completely replaced a few
> months ago. Ride height at OM standard. Southland air bags.
> Road master tow bar and bracket.
>
> John, I really hope it isn't the tow bar. That would be a
> big disappointment. I am uncomfortable asking anyone else to
> drive it under these circumstances, but I'll find a way to
> get a look at the towing gear in action.
>
> Thanks for the suggestions, guys. This one is headache
> inducing, quite literally.
>
> --
> 1973 Sequoia 260 (since 2011)
> In-transit, westward
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
_______________________________________________
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Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
L Conley 260 glacier
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| Re: [GMCnet] 700 trouble free miles, with a few quirks [message #142555 is a reply to message #142545] |
Tue, 06 September 2011 00:23 |
mtnman111
Messages: 20
Registered: August 2004
Karma: 0
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Junior Member |
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Andrew, in my op you're running way too much press, the 80 psi is for max weight, you're no where near that, i run 55to 60 psi in my 74 26ft glacier, suggest you give it a try, bet you'll like it. good luck. Larry Conley, riverside co, ca.
--- On Mon, 9/5/11, Andrew <reynhout@quesera.com> wrote:
> From: Andrew <reynhout@quesera.com>
> Subject: Re: [GMCnet] 700 trouble free miles, with a few quirks
> To: gmclist@temp.gmcnet.org
> Date: Monday, September 5, 2011, 9:22 PM
>
>
> Re: wander, I think from the rear...
>
> I should have mentioned that the entire rear suspension was
> replaced by Southland MHC. Subsequently, the coach has been
> towed from the front for about 100 miles. I think the wander
> got worse after that tow, although I also switched from a
> tow dolly to a flat-tow setup at the same time.
>
> Replacing the steel wheels helped tremendously. I
> transferred my new tires (800 miles) from the 16" steel
> wheels to the new Eagles. The new rims made the difference
> between consistently unsafe and merely occasionally
> surprising. I have experience towing much larger and heavier
> things than a Honda CR-V, so I want to believe that this is
> a correctable problem.
>
> This issue is a minor wander when not towing, but with the
> car behind it turns into a fairly significant wag that
> requires active dampening. It was constant and exhausting
> before the new wheels. Now it's frequent and usually quickly
> caught, but I don't think anyone would tow if this was
> normal.
>
> Jim, it's a 1973, newish 225/75 R16 tires, load range E,
> inflated to 80psi. Rear suspension completely replaced a few
> months ago. Ride height at OM standard. Southland air bags.
> Road master tow bar and bracket.
>
> John, I really hope it isn't the tow bar. That would be a
> big disappointment. I am uncomfortable asking anyone else to
> drive it under these circumstances, but I'll find a way to
> get a look at the towing gear in action.
>
> Thanks for the suggestions, guys. This one is headache
> inducing, quite literally.
>
> --
> 1973 Sequoia 260 (since 2011)
> In-transit, westward
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
L Conley 260 glacier
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| Re: [GMCnet] 700 trouble free miles, with a few quirks [message #142564 is a reply to message #142545] |
Tue, 06 September 2011 05:15 |
James Hupy
Messages: 6806
Registered: May 2010
Karma: -62
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Senior Member |
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Andrew, When you say that the rear suspension was replaced, I would guess
that it was upgraded to the larger bogie pins, and new bushings, Perhaps the
"Top Hats", the axial play flanged bushings that are adjusted by the large
nut on the bogie pins, are set up too loosely after initial break-in. I
would jack up the rear of the coach under the bogie boxes, deflate the air
bags, and with the wheels and tires off the ground, attempt to move the
assemblies by pulling towards you and pushing away from you alternately.
Look and feel for any motion at the intersection of the bogie arms and pins.
If any movement is seen or felt, or any clunking is heard, the axial
adjustment should be tightened. Bend back the locking tabs on the nuts,
loosen the adjustment nuts, and retorque to 25 foot pounds. If they have
worn some, when you go to loosen the nuts, they will be easily turned. This
is the area that I would investigate first. I would concur that 80 psi in
the tires seems excessive on a lightly loaded coach. On my 78 Royale, which
is one of the heavier coaches, I run 65 psi with steel wheels and BF
Goodrich Steel belted tread/ fabric sidewall radial tires. When I run over
70 psi, the rear end seems unstable like you describe also. Try the
inflation pressure first, check tire temps after some high speed driving and
see where you are. The more that you know about your coach, the better you
will understand the handling characteristics of it. As the old saying goes,
"One man's medicine is another man's poison." Same can be said for handling.
It is a very subjective thing to describe.
Jim Hupy
Salem, OR
78 GMC Royale 403
On Mon, Sep 5, 2011 at 9:22 PM, Andrew <reynhout@quesera.com> wrote:
>
>
> Re: wander, I think from the rear...
>
> I should have mentioned that the entire rear suspension was replaced by
> Southland MHC. Subsequently, the coach has been towed from the front for
> about 100 miles. I think the wander got worse after that tow, although I
> also switched from a tow dolly to a flat-tow setup at the same time.
>
> Replacing the steel wheels helped tremendously. I transferred my new tires
> (800 miles) from the 16" steel wheels to the new Eagles. The new rims made
> the difference between consistently unsafe and merely occasionally
> surprising. I have experience towing much larger and heavier things than a
> Honda CR-V, so I want to believe that this is a correctable problem.
>
> This issue is a minor wander when not towing, but with the car behind it
> turns into a fairly significant wag that requires active dampening. It was
> constant and exhausting before the new wheels. Now it's frequent and usually
> quickly caught, but I don't think anyone would tow if this was normal.
>
> Jim, it's a 1973, newish 225/75 R16 tires, load range E, inflated to 80psi.
> Rear suspension completely replaced a few months ago. Ride height at OM
> standard. Southland air bags. Road master tow bar and bracket.
>
> John, I really hope it isn't the tow bar. That would be a big
> disappointment. I am uncomfortable asking anyone else to drive it under
> these circumstances, but I'll find a way to get a look at the towing gear in
> action.
>
> Thanks for the suggestions, guys. This one is headache inducing, quite
> literally.
>
> --
> 1973 Sequoia 260 (since 2011)
> In-transit, westward
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
>
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
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| Re: 700 trouble free miles, with a few quirks [message #142570 is a reply to message #142536] |
Tue, 06 September 2011 08:53 |
 |
Matt Colie
Messages: 8547
Registered: March 2007
Location: S.E. Michigan
Karma: 7
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Senior Member |
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| Andrew wrote on Mon, 05 September 2011 23:27 |
Re: speedo/odo discrepancies.. I wondered if the new tire size would have an effect, but the comments I read in other threads suggested that it would be very small.
If it's just the tires, shouldn't the speedo and odo variances be the same percentages? I'm seeing the speedo almost 10% low all the time at highway speed, but the odo is nearly dead on at times, and just a couple percent low others.
The fact that they aren't in obvious relation is why I guessed that something was up in the internals of the speedo. I would have expected the odo to lag the speedo, but that might just be because they don't work the way I imagine they do.
The reason this is an incredibly important problem to solve is that otherwise, my mpg math is a total fiction.
(Kidding. I know that the full precision result is "about eight-point-expensive".)
One positive side effect of having this trip be so delayed is that gas prices have dropped a fair bit in the last couple months.
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Andrew,
Yes, the Speedo and Odo should agree. - Mine do, but they are both wrong.
I am still running 8.75x16.5 on stock wheels and both the speedometer and odometer read about 7% (actually 6.5) low. When you figure that this means an indicted 65 is real close to 70 and that cam matter in places that tag out of state plates (like Ohio) and that you gas mileage can look lower than it truly is.
Matt
Matt & Mary Colie - Chaumière -'73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Electronically Controlled Quiet Engine Cooling Fan with OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Near DTW - Twixt A2 and Detroit
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| Re: 700 trouble free miles, with a few quirks [message #142584 is a reply to message #142582] |
Tue, 06 September 2011 10:36 |
Carl S.
Messages: 4186
Registered: January 2009
Location: Tucson, AZ.
Karma: 13
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Senior Member |
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I agree with the opinion that you are running too much tire pressure. I run mine at 65 psi and have had good handling and even wear as a result. At 80 psi, the tires are too hard and will make the back end (and probably the front end, to a lesser extent) squirrely.
Carl Stouffer
'75 ex Palm Beach
Tucson, AZ.
Chuck Aulgur Reaction Arm Disc Brakes, Quadrabags, 3.70 LSD final drive, Lenzi knuckles/hubs, Dodge Truck 16" X 8" front wheels, Rear American Eagles, Solar battery charging. GMCSJ and GMCMI member
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| Re: [GMCnet] 700 trouble free miles, with a few quirks [message #142665 is a reply to message #142564] |
Wed, 07 September 2011 07:29 |
Andrew
Messages: 213
Registered: April 2011
Location: Connecticut
Karma: 0
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Senior Member |
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| James Hupy wrote on Tue, 06 September 2011 06:15 |
Andrew, When you say that the rear suspension was replaced, I would guess
that it was upgraded to the larger bogie pins, and new bushings,
|
It's actually the same old smaller pins, just because that was the core that Southland wanted to sell me. Thank you for the run-in check suggestions and adjustment procedures. I'll take a look in the next few days.
Thanks for all of the over-inflation comments too -- I hope my handling issues are really that simple. I have been checking tire temps across the treads and not felt or measured anything surprising. The tire shop read the number off the sidewall, and I didn't even think to question it. That'd be a huge relief..!
1973 Sequoia 260 (since 2011)
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