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| timing question [message #138303] |
Wed, 10 August 2011 17:54  |
chasingsummer
Messages: 434
Registered: May 2011
Location: asheboro, nc
Karma: 0
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i do not have a timing light, and presently i think my coach runs good, but has a little dieseling problem(i think dieseling is proper word. it wants to keep running when i turn off key,
i am thinking i need to touch distributor, but seek additional knowledge,
75 455 with hei, if i assumed all were set and working proper, should i be thinking cw or ccw and how much rotation is considered a lot of rotation
thanks bgk
brian
asheboro, nc
75 eleganza, 74 build
119k miles and counting,
DOG HOUSE
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| Re: timing question [message #138304 is a reply to message #138303] |
Wed, 10 August 2011 18:03  |
C Boyd
Messages: 2629
Registered: April 2006
Karma: 18
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Senior Member |
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| chasingsummer wrote on Wed, 10 August 2011 18:54 |
i do not have a timing light, and presently i think my coach runs good, but has a little dieseling problem(i think dieseling is proper word. it wants to keep running when i turn off key,
i am thinking i need to touch distributor, but seek additional knowledge,
75 455 with hei, if i assumed all were set and working proper, should i be thinking cw or ccw and how much rotation is considered a lot of rotation
thanks bgk
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Sir: it is bassakards from a Chevy. Move the vacuum adv toward the radiator retards the timing. You might have your idle set to high, 650-700, or a small vacuum leak somewhere will cause this also. Sometimes it is just easier to turn the engine off in gear.
C. Boyd
76 Crestmont
East Tennessee
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| Re: [GMCnet] timing question [message #138315 is a reply to message #138304] |
Wed, 10 August 2011 19:14 |
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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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Brian,
I agree 100% with Chuck; dieseling can lead to a bigger problem, backfires!
If that happens you will probably wind up blowing up a muffler (or two);
guess how I know! ;-)
You cannot set the timing or idle properly without the proper tools. You
need a timing light and a tachometer. If you want to set the idle fuel
mixture you will also need a vacuum gage. I bought all three from AutoZone
(bet you guys are surprised it WASN'T Harbor Freight!). I also bought a
compression testing kit. While you're at AutoZone get some spray brake
cleaner.
Remove the distributor cap and make sure that the mechanical advance
mechanism is working properly. Put a drop of oil on each of the pivot
points.
Disconnect the hose to the vacuum advance and connect a clean piece of
tubing to it and suck on the free end and watch and see if the plate moves.
Leave the hose to the vacuum advance disconnected and plug the open end with
a screw.
Clean the timing mark plate above the harmonic balancer. Clean the slot in
the harmonic balancer and use some white out or white paint to highlight the
slot to make it easier to see.
Connect the timing light to number 1 cylinder spark plug wire (front
cylinder on the drivers side) and the plus and minus terminals of the
battery. Loosen the bolt that holds the distributor clamp tight. Start the
engine and let it warm up until the choke opens. You probably will have to
"blip" the throttle for a second to get the choke to open and get the
butterfly off high idle. Set the idle to 650-700 RPM as Chuck notes below.
Once the engine is running smoothly use the timing light to check the
riming, it should be 8 degrees. To advance the timing turn the distributor
counter clockwise and to retard clockwise.
Once you've set the timing lock the distributor back down. After doing that
take the screw out of the vacuum line and reconnect it to the vacuum
advance. Start the engine let it warm up and make sure the idle speed is
650-700 rpm.
Oh oh! I just noticed something in your signature; "118k miles and counting"
if you have not replaced the timing chain you need to do it before you even
bother trying to adjust the timing.
Regards,
Rob M.
Sydney, Australia
AUS '75 Avion-The Blue Streak TZE365V100428
USA '75 Avion-Double Trouble TZE365V100426
-----Original Message-----
From: gmclist-bounces@temp.gmcnet.org
[mailto:gmclist-bounces@temp.gmcnet.org] On Behalf Of Charles Boyd
Sent: Thursday, 11 August 2011 9:03 AM
To: gmclist@temp.gmcnet.org
Subject: Re: [GMCnet] timing question
i do not have a timing light, and presently i think my coach runs good, but
has a little dieseling problem(i think dieseling is proper word. it wants to
keep running when i turn off key, i am thinking i need to touch distributor,
but seek additional knowledge,
75 455 with hei, if i assumed all were set and working proper, should i be
thinking cw or ccw and how much rotation is considered a lot of rotation
thanks bgk
--
brian
asheboro, nc
75 eleganza 2 74 build
118k miles and counting,
DOG HOUSE
Sir: it is bassakards from a Chevy. Move the vacuum adv toward the radiator
retards the timing. You might have your idle set to high, 650-700, or a
small vacuum leak somewhere will cause this also. Sometimes it is just
easier to turn the engine off in gear.
--
C. Boyd
76 Crestmont by Midas
East Tennessee
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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: timing question [message #138385 is a reply to message #138303] |
Thu, 11 August 2011 00:24 |
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mike miller
Messages: 3576
Registered: February 2004
Location: Hillsboro, Oregon
Karma: 0
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| chasingsummer wrote on Wed, 10 August 2011 15:54 |
... but has a little dieseling problem(i think dieseling is proper word. it wants to keep running when i turn off key,
i am thinking i need to touch distributor, but seek additional knowledge, ...
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General question on gas engine dieseling:
If the engine continues to "run" with the ignition turned off (as in: no power to the HEI/coil ect...) how can timing be the cause?
Maybe I am missing something, but I would THINK it would have to be carb or vacuum related.
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: timing question [message #138525 is a reply to message #138303] |
Thu, 11 August 2011 17:39 |
chasingsummer
Messages: 434
Registered: May 2011
Location: asheboro, nc
Karma: 0
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Senior Member |
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so since i startd this , additional dumb question,
since this autozone part is meant to close flapps, can this be accomplished to adding a sprint that will pull flapps closed? and yes i know flapps is not proper word, but correct one excapes me for moment, crs, when added to getting older, mixed with stupid things done when a kid equals making up words when the proper one excapes me.
brian
asheboro, nc
75 eleganza, 74 build
119k miles and counting,
DOG HOUSE
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| Re: timing question [message #138528 is a reply to message #138525] |
Thu, 11 August 2011 17:59 |
C Boyd
Messages: 2629
Registered: April 2006
Karma: 18
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Senior Member |
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| chasingsummer wrote on Thu, 11 August 2011 18:39 |
so since i startd this , additional dumb question,
since this autozone part is meant to close flapps, can this be accomplished to adding a sprint that will pull flapps closed? and yes i know flapps is not proper word, but correct one excapes me for moment, crs, when added to getting older, mixed with stupid things done when a kid equals making up words when the proper one excapes me.
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Sir: it is not meant to close anystuff. It is an electric solenoid that when activated jumps out to hold the throttle at idle. The rod that jumps out is adjustable by turning to set desired idle speed. It allows you to back the carb throttle stop all the way out so the butterflies will close all the way when the solenoid is deactivated. Some applications hooked it to the AC compressor to raise idle speed when AC is turned on. Sorry for the confusion.
C. Boyd
76 Crestmont
East Tennessee
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| Re: timing question [message #138552 is a reply to message #138303] |
Thu, 11 August 2011 19:09 |
chasingsummer
Messages: 434
Registered: May 2011
Location: asheboro, nc
Karma: 0
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Senior Member |
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so if incorrect timing could be causing, should i be thinking of maybe slightly rotating cw or ccw on dizzy,
brian
asheboro, nc
75 eleganza, 74 build
119k miles and counting,
DOG HOUSE
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| Re: timing question [message #138553 is a reply to message #138552] |
Thu, 11 August 2011 19:21 |
C Boyd
Messages: 2629
Registered: April 2006
Karma: 18
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Senior Member |
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| chasingsummer wrote on Thu, 11 August 2011 20:09 |
so if incorrect timing could be causing, should i be thinking of maybe slightly rotating cw or ccw on dizzy,
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ccw
C. Boyd
76 Crestmont
East Tennessee
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| Re: timing question [message #138565 is a reply to message #138553] |
Thu, 11 August 2011 19:44 |
C Boyd
Messages: 2629
Registered: April 2006
Karma: 18
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Senior Member |
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| C Boyd wrote on Thu, 11 August 2011 20:21 |
| chasingsummer wrote on Thu, 11 August 2011 20:09 |
so if incorrect timing could be causing, should i be thinking of maybe slightly rotating cw or ccw on dizzy,
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ccw
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Sir: you do have the vacuum advance hooked to ported vacuum (no vacuum at idle)? If you have manifold vacuum to the dist it could contribute to the dieseling.
C. Boyd
76 Crestmont
East Tennessee
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| Re: [GMCnet] timing question [message #138617 is a reply to message #138552] |
Thu, 11 August 2011 23:10 |
Ken Henderson
Messages: 8726
Registered: March 2004
Location: Americus, GA
Karma: 9
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Senior Member |
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Brian,
If you're just trying to correct dieseling, tinkering with the timing,
without a timing light, and without the knowledge to even determine which
way to turn the distributor, is NOT what you should be doing.
The only adjustment you should attempt is to turn the idle adjustment screw
out just a little to slow the idle. If that doesn't help, get someone to
show you where the idle mixture screws are and how to adjust them. If that
doesn't help, get a the mixture tutor to show you how to tell which way the
distributor should be turned to advance or retard timing. Mark it on the
distributor cap with an arrow so you'll always remember it. THEN use a
timing light to slightly adjust the timing to its correct setting. Which
probably won't be necessary after you adjust the idle. And probably won't
help your dieseling problem anyway, IMHO..
Ken H.
Americus, GA
'76 X-Birchaven w/Cad500/Howell EFI+ & EBL
www.gmcwipersetc.com
On Thu, Aug 11, 2011 at 8:09 PM, brian <chasingsummer@triad.rr.com> wrote:
>
>
> so if incorrect timing could be causing, should i be thinking of maybe
> slightly rotating cw or ccw on dizzy,
> --
>
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Ken Henderson
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www.gmcwipersetc.com
Large Wiring Diagrams
76 X-Birchaven
76 X-Palm Beach
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| Re: timing question [message #138795 is a reply to message #138385] |
Fri, 12 August 2011 23:25 |
Bob de Kruyff
Messages: 4260
Registered: January 2004
Location: Chandler, AZ
Karma: 1
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Senior Member |
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| Mike Miller wrote on Wed, 10 August 2011 23:24 |
| chasingsummer wrote on Wed, 10 August 2011 15:54 |
... but has a little dieseling problem(i think dieseling is proper word. it wants to keep running when i turn off key,
i am thinking i need to touch distributor, but seek additional knowledge, ...
|
General question on gas engine dieseling:
If the engine continues to "run" with the ignition turned off (as in: no power to the HEI/coil ect...) how can timing be the cause?
Maybe I am missing something, but I would THINK it would have to be carb or vacuum related.
|
Almost always, dieseling is due to high idle speed, however, advanced timing can cause high idle speed so it is not always the carb adjustment.
Bob de Kruyff
78 Eleganza
Chandler, AZ
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| Re: timing question [message #138816 is a reply to message #138795] |
Sat, 13 August 2011 05:44 |
Ken Burton
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
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Senior Member |
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| Bob de Kruyff wrote on Fri, 12 August 2011 23:25 |
| Mike Miller wrote on Wed, 10 August 2011 23:24 |
| chasingsummer wrote on Wed, 10 August 2011 15:54 |
... but has a little dieseling problem(i think dieseling is proper word. it wants to keep running when i turn off key,
i am thinking i need to touch distributor, but seek additional knowledge, ...
|
General question on gas engine dieseling:
If the engine continues to "run" with the ignition turned off (as in: no power to the HEI/coil ect...) how can timing be the cause?
Maybe I am missing something, but I would THINK it would have to be carb or vacuum related.
|
Almost always, dieseling is due to high idle speed, however, advanced timing can cause high idle speed so it is not always the carb adjustment.
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Along that line, where is your vacuum advance attached to? It is suppose to be on the front port of the carb. If it is attached to manifold vacuum you will have 10 degrees additional advance at idle. Another possibility, although I have never seen it, is the TVS is stuck. Dick Paterson told me he has seen it.
An easy check would be:
1. start the engine,
2. let it idle
3 remove the vacuum hose from the distributor
4. there should be no vacuum on that hose at an idle. If there is vacuum then the TVS is stuck or you have the hose connected to the wrong port.
Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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| Re: timing question [message #138868 is a reply to message #138303] |
Sat, 13 August 2011 10:50 |
chasingsummer
Messages: 434
Registered: May 2011
Location: asheboro, nc
Karma: 0
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Senior Member |
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i see my tvs is either bad or p.o. , i dont know, the lower 2 ports are closed off, and the upper one is feeding my cruise module,
time to make it better,
should cruise unit , which i have tried once to used and nothing happened , should it have manifold vacuum or this ported vacuum,
also, on massenger side, one of my vacuum hoses hooks to a metal line that runs towards rear direction beside valve cover, then goes down beloe engine to something, raining too hard to lay in driveway, any ideas wht this line goes to and if it is manifold or ported vacuum.
also, i see pvc goes to breather housing, but breather also has the air bleed valve and control damper, how inportant are they and are they manifold or ported?
thansk in advance,
brian
brian
asheboro, nc
75 eleganza, 74 build
119k miles and counting,
DOG HOUSE
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| Re: timing question [message #138878 is a reply to message #138868] |
Sat, 13 August 2011 12:21 |
C Boyd
Messages: 2629
Registered: April 2006
Karma: 18
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Senior Member |
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| chasingsummer wrote on Sat, 13 August 2011 11:50 |
i see my tvs is either bad or p.o. , i dont know, the lower 2 ports are closed off, and the upper one is feeding my cruise module,
time to make it better,
should cruise unit , which i have tried once to used and nothing happened , should it have manifold vacuum or this ported vacuum,
also, on massenger side, one of my vacuum hoses hooks to a metal line that runs towards rear direction beside valve cover, then goes down beloe engine to something, raining too hard to lay in driveway, any ideas wht this line goes to and if it is manifold or ported vacuum.
also, i see pvc goes to breather housing, but breather also has the air bleed valve and control damper, how inportant are they and are they manifold or ported?
thansk in advance,
brian
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Sir: the cruise is manifold vacuum. The metal line goes to the transmission modulater valve and is manifold vacuum. The airfilter diversion valve is manifold vacuum and goes thru a temp controlled switch on the bottom of the airfilter to the valve. On cold start up it closes the intake of the airfilter and diverts it to exhaust manifold heated air for faster warm ups. Most have this plugged at the sorce. The only thing ported vacuum is trhe dist. Make sure the pcv hose and the canister hose fits the carb ports snuggly.
C. Boyd
76 Crestmont
East Tennessee
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| Re: timing question [message #138884 is a reply to message #138303] |
Sat, 13 August 2011 12:51 |
chasingsummer
Messages: 434
Registered: May 2011
Location: asheboro, nc
Karma: 0
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Senior Member |
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cboyd
i greatly appreciate all your input, i think i am going to leave the vacuum stuff on breather disconnected except for pvc. the riser piece from exhaust is not present anyway,
i will be firing up shortly and seeing i either made it better, or if somehpow this tvs thigs was bad , it has not ran bad, but gas mileage has been poor.
trying to get ready for camping trip, maiden overnighter for with and i, aug 24th and 25th. if all goes well the additional night will be added. moonshine creek campground, not too far south of knoxville in nc mountains.
do u know of any easy checks which may help with cruise control. ?
thanks bgk
brian
asheboro, nc
75 eleganza, 74 build
119k miles and counting,
DOG HOUSE
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| Re: timing question [message #138914 is a reply to message #138884] |
Sat, 13 August 2011 17:26 |
C Boyd
Messages: 2629
Registered: April 2006
Karma: 18
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Senior Member |
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| chasingsummer wrote on Sat, 13 August 2011 13:51 |
cboyd
i greatly appreciate all your input, i think i am going to leave the vacuum stuff on breather disconnected except for pvc. the riser piece from exhaust is not present anyway,
i will be firing up shortly and seeing i either made it better, or if somehpow this tvs thigs was bad , it has not ran bad, but gas mileage has been poor.
trying to get ready for camping trip, maiden overnighter for with and i, aug 24th and 25th. if all goes well the additional night will be added. moonshine creek campground, not too far south of knoxville in nc mountains.
do u know of any easy checks which may help with cruise control. ?
thanks bgk
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Just check all the hoses. To set the cruise push the button all the way in and release slowly. You might want to down load some manuals to disc to take with you. Make sure and read the operater manual. The mantience manual is a must. Never leave home without it.
http://www.bdub.net/manuals/index.html Don`t forget to take pics on the trip.
C. Boyd
76 Crestmont
East Tennessee
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