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Running Rough [message #318615] Tue, 06 June 2017 23:30 Go to next message
misnomer is currently offline  misnomer   United States
Messages: 40
Registered: April 2015
Location: Reno
Karma: 1
Member

Hey gents, we've finished a bunch of interior updates and are now running into running issues. My last trip going south on US95 in Nevada, I lost a decent chunk of power climbing up toward Tonopah. It was noticeable but not a showstopper, so I continued the journey. A couple hundred miles and a couple days of mountain biking later, it kicked back in somewhere in the virgin river gorge, and drove home without issue.

I was down for a little while with a power steering leak which I've now repaired and gotten back to driving the coach and wouldn't you know, it's gone down on power again. So far to chase it down I've replace the spark plugs, all had decent use, but none looked richer or leaner or gooeyer than the others, new plug wires, distributor cap, rotor. I'll dig out my timing light to see if that's within reason.

It's idling kind of lopey, revs just fine without load, but under load it struggles to get the coach rolling and has minor surging and stalling. I did notice when it was running with the air cleaner off, if I covered the throttle intake with my hand the idle raised and smoothed out - leading me to think it might be running lean?

I'm open to ideas and suggestions. I miss camping.


77 Birchaven 23 w/ 455 Reno, NV
Re: [GMCnet] Running Rough [message #318617 is a reply to message #318615] Wed, 07 June 2017 00:08 Go to previous messageGo to next message
jimk is currently offline  jimk   United States
Messages: 6734
Registered: July 2006
Location: Belmont, CA
Karma: 9
Senior Member
Check your Vacuum lines for cracks and loose connection.

On Tue, Jun 6, 2017 at 9:30 PM, John Yurtinus wrote:

> Hey gents, we've finished a bunch of interior updates and are now running
> into running issues. My last trip going south on US95 in Nevada, I lost a
> decent chunk of power climbing up toward Tonopah. It was noticeable but
> not a showstopper, so I continued the journey. A couple hundred miles and a
> couple days of mountain biking later, it kicked back in somewhere in the
> virgin river gorge, and drove home without issue.
>
> I was down for a little while with a power steering leak which I've now
> repaired and gotten back to driving the coach and wouldn't you know, it's
> gone
> down on power again. So far to chase it down I've replace the spark plugs,
> all had decent use, but none looked richer or leaner or gooeyer than the
> others, new plug wires, distributor cap, rotor. I'll dig out my timing
> light to see if that's within reason.
>
> It's idling kind of lopey, revs just fine without load, but under load it
> struggles to get the coach rolling and has minor surging and stalling. I did
> notice when it was running with the air cleaner off, if I covered the
> throttle intake with my hand the idle raised and smoothed out - leading me
> to
> think it might be running lean?
>
> I'm open to ideas and suggestions. I miss camping.
>
> --
> 77 Birchaven 23 w/ 455
> Reno, NV
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>



--
Jim Kanomata
Applied/GMC, Newark,CA
jimk@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502
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Jim Kanomata
Applied/GMC
jimk@appliedairfilters.com
www.appliedgmc.com
1-800-752-7502
Re: [GMCnet] Running Rough [message #318626 is a reply to message #318617] Wed, 07 June 2017 05:00 Go to previous messageGo to next message
Bruce Hart is currently offline  Bruce Hart   United States
Messages: 1501
Registered: October 2011
Location: La Grange, Wyoming
Karma: 5
Senior Member
Replace your fuel filters.

On Tue, Jun 6, 2017 at 11:08 PM, Jim Kanomata wrote:

> Check your Vacuum lines for cracks and loose connection.
>
> On Tue, Jun 6, 2017 at 9:30 PM, John Yurtinus wrote:
>
>> Hey gents, we've finished a bunch of interior updates and are now running
>> into running issues. My last trip going south on US95 in Nevada, I lost a
>> decent chunk of power climbing up toward Tonopah. It was noticeable but
>> not a showstopper, so I continued the journey. A couple hundred miles
> and a
>> couple days of mountain biking later, it kicked back in somewhere in the
>> virgin river gorge, and drove home without issue.
>>
>> I was down for a little while with a power steering leak which I've now
>> repaired and gotten back to driving the coach and wouldn't you know, it's
>> gone
>> down on power again. So far to chase it down I've replace the spark
> plugs,
>> all had decent use, but none looked richer or leaner or gooeyer than the
>> others, new plug wires, distributor cap, rotor. I'll dig out my timing
>> light to see if that's within reason.
>>
>> It's idling kind of lopey, revs just fine without load, but under load it
>> struggles to get the coach rolling and has minor surging and stalling. I
> did
>> notice when it was running with the air cleaner off, if I covered the
>> throttle intake with my hand the idle raised and smoothed out - leading
> me
>> to
>> think it might be running lean?
>>
>> I'm open to ideas and suggestions. I miss camping.
>>
>> --
>> 77 Birchaven 23 w/ 455
>> Reno, NV
>>
>> _______________________________________________
>> GMCnet mailing list
>> Unsubscribe or Change List Options:
>> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>>
>
>
>
> --
> Jim Kanomata
> Applied/GMC, Newark,CA
> jimk@appliedairfilters.com
> http://www.appliedgmc.com
> 1-800-752-7502
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>



--
Bruce Hart
1976 Palm Beach
Milliken, Co
GMC=Got More Class
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Bruce Hart 1976 Palm Beach 1977 28' Kingsley La Grange, Wyoming
Re: Running Rough [message #318644 is a reply to message #318615] Wed, 07 June 2017 10:18 Go to previous messageGo to next message
kerry pinkerton is currently offline  kerry pinkerton   United States
Messages: 2565
Registered: July 2012
Location: Harvest, Al
Karma: 15
Senior Member
Had a similar problem and chased it a while before I decided to verify the firing order for the 9th time. Found a spark plug wire dangling. Problem solved.

Kerry Pinkerton - North Alabama Had 5 over the years. Currently have a '06 Fleetwood Discovery 39L
Re: Running Rough [message #318646 is a reply to message #318615] Wed, 07 June 2017 10:26 Go to previous messageGo to next message
Carl S. is currently offline  Carl S.   United States
Messages: 4186
Registered: January 2009
Location: Tucson, AZ.
Karma: 13
Senior Member

Your statement, "I did notice when it was running with the air cleaner off, if I covered the throttle intake with my hand the idle raised and smoothed out" indicates a vacuum leak, so do as Jim suggested and check all your vacuum lines for leaks. The fuel filters were the first thing to come to my mind after that, as Bruce suggested. Kerry had a good suggestion as well, check the firing order and make sure that you not only don't have a loose plug wire, but that you don't have a couple of wires crossed up.

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
Re: Running Rough [message #318672 is a reply to message #318646] Wed, 07 June 2017 15:58 Go to previous messageGo to next message
ree_eric is currently offline  ree_eric   
Messages: 43
Registered: February 2004
Location: Alexandria, Ontario, Cana...
Karma: 0
Member
What kind of vacuum leak could fix itself for a while? PCV valve sticking?

Eric & Ree '74 ex-Sequoia (parts) '75 Eleganza (TB, exhaust x-over blocking plates, Manny reaction arms and discs, 3"exhaust rear muffler, aux vacuum, fuel tank sealing, rebuilt senders and new rubber, propane hot water heater.) Alexandria, Ontario, Canada
Re: Running Rough [message #318682 is a reply to message #318672] Wed, 07 June 2017 17:37 Go to previous messageGo to next message
Matt Colie is currently offline  Matt Colie   United States
Messages: 8547
Registered: March 2007
Location: S.E. Michigan
Karma: 7
Senior Member
ree_eric wrote on Wed, 07 June 2017 16:58
What kind of vacuum leak could fix itself for a while? PCV valve sticking?

Eric,
Vacuum leaks rarely come and go, but can easily change volume with heat. Rubber hoses do this all the time and it makes them a bear to find.
Old cheap and sleazy shop trick. Have a CO2 fire extinguisher handy and spray carburetor cleaner - not a lot - around the engine top. If someplace you spray changes things, there you go....

Matt - only had to use the extinguisher once.


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
Re: Running Rough [message #318827 is a reply to message #318615] Sat, 10 June 2017 15:26 Go to previous messageGo to next message
misnomer is currently offline  misnomer   United States
Messages: 40
Registered: April 2015
Location: Reno
Karma: 1
Member

Good call - found the vacuum leak this morning. Runs well now at wider throttle (secondaries open), still a bit stumbling at low throttle. Will probably just replace all the vacuum lines while I'm in there. At least she's roadworthy again, will see if she passes smog...

77 Birchaven 23 w/ 455 Reno, NV
Re: Running Rough [message #318829 is a reply to message #318615] Sat, 10 June 2017 16:25 Go to previous messageGo to next message
misnomer is currently offline  misnomer   United States
Messages: 40
Registered: April 2015
Location: Reno
Karma: 1
Member

Ok I give up, anybody know of a shop in Reno that can handle these rigs and knows their way around the quadrajet? Failed smog and I'm tired if fighting it, time to call in the professionals!

77 Birchaven 23 w/ 455 Reno, NV
Re: [GMCnet] Running Rough [message #318843 is a reply to message #318829] Sat, 10 June 2017 23:00 Go to previous messageGo to next message
jimk is currently offline  jimk   United States
Messages: 6734
Registered: July 2006
Location: Belmont, CA
Karma: 9
Senior Member
Send me your report of the test .
I will then tell you what you can do to to pass.
I was not aware that Nevada had Smog test.

On Sat, Jun 10, 2017 at 2:25 PM, John Yurtinus wrote:

> Ok I give up, anybody know of a shop in Reno that can handle these rigs
> and knows their way around the quadrajet? Failed smog and I'm tired if
> fighting it, time to call in the professionals!
> --
> 77 Birchaven 23 w/ 455
> Reno, NV
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
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>



--
Jim Kanomata
Applied/GMC, Newark,CA
jimk@appliedairfilters.com
http://www.appliedgmc.com
1-800-752-7502
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Jim Kanomata
Applied/GMC
jimk@appliedairfilters.com
www.appliedgmc.com
1-800-752-7502
Re: [GMCnet] Running Rough [message #318844 is a reply to message #318843] Sun, 11 June 2017 00:13 Go to previous messageGo to next message
misnomer is currently offline  misnomer   United States
Messages: 40
Registered: April 2015
Location: Reno
Karma: 1
Member

Washoe and Clark counties have smog requirements, the rest of the state doesn't.

Hydrocarbons are ~5000 ppm, allowable is 1400. So, assuming running overly rich.


77 Birchaven 23 w/ 455 Reno, NV
Re: [GMCnet] Running Rough [message #318845 is a reply to message #318844] Sun, 11 June 2017 00:40 Go to previous message
Ken Burton is currently offline  Ken Burton   United States
Messages: 10030
Registered: January 2004
Location: Hebron, Indiana
Karma: 10
Senior Member
misnomer wrote on Sun, 11 June 2017 00:13
Washoe and Clark counties have smog requirements, the rest of the state doesn't.

Hydrocarbons are ~5000 ppm, allowable is 1400. So, assuming running overly rich.



Hardly anybody lives in the rest of the counties.
2.6 million or so in those two counties.
400 K or so in the rest of the state.

Register your MH in Carson city, Virginia City, or Fernly if necessary.


Ken Burton - N9KB
76 Palm Beach
Hebron, Indiana
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