Running Rough

john yurtinus

New member
Apr 23, 2015
40
0
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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
 
Check your Vacuum lines for cracks and loose connection.

> 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
http://www.appliedgmc.com
1-800-752-7502
 
Replace your fuel filters.

> Check your Vacuum lines for cracks and loose connection.
>

>
> > 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
> 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
 
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

77 Eleganza II, 403CI, Manny Brakes, 1 ton, tranny, lots of aluminum goodies.

http://www.bdub.net/pinkerton/

'03 Fleetwood Discovery 39L
 
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
 
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
 
> 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 - '73 Glacier 23 - Members GMCMI, GMCGL, GMCES
Still Loving OE Rear Drum Brakes with Applied Control Arms
SE Michigan - Twixt A2 and Detroit
 
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
 
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
 
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.

> 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:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>

--
Jim Kanomata
Applied/GMC, Newark,CA
jimk
http://www.appliedgmc.com
1-800-752-7502
 
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
 
> 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