Still having issues in Colorado

R

robert peesel

New member
Jan 7, 2011
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Since we purchased a fixer-upper home in Conifer, Co., it has been quite a while since I was able to get back to working on my GMC. When I last
posted I had just driven my GMC across the country and lost power just as I was passing Denver on the highway. The loss of power was such that I was
only able to reach a top speed of about 13 miles an hour for the last 20 miles of the drive. Most of the suggestions I was given revolved around the
fuel filter as the loss of power was not gradual. The consensus was that the filter may have collapsed.

After much delay I was finally able to get the filter out and was dismayed to see that it looked perfect. I put the new filter in along with a new
battery and fired the GMC up. It ran rough for a bit as it had been sitting for way too long but soon began to smooth out. I had high hopes when I
backed out of the parking spot. Unfortunately, those hopes vanished immediately as I found that I still had no power. The GMC was barely able to
make it back up the slight incline to get back to parking spot despite having the pedal to the floor.

I am going to reach out to the local club as well, but was hoping to get as much input as possible toward possible/likely solutions.

Robert
--
Robert Peesel

1976 Royale 26'

Side Dry Bath

Morrison, Colorado
 
I think I'd look for a second filter somewhere.
Hal
--
1977 Royale 101348,

1977 Royale 101586, Diesel powered,

1974 Eagle Bus 45',w/slideout
 
Hal,

That's a good point. I will crawl under to see if another inline filter had been installed in the past.

Thanks for the idea!
--
Robert Peesel

1976 Royale 26'

Side Dry Bath

Morrison, Colorado
 
If it's not a filter problem could be the mechical fuel pump is defective . Try substituting an electric pump if in doubt. Are you sure the ignition
components are ok? Pull the plugs and do a compression check. If the motor has a lot of miles on it the timing chain may have skipped a tooth?
--
Roy Keen
Minden,NV
76 X Glenbrook
 
It certainly does sound like fuel starvation. It could also be a clogged air filter or even a collapsed muffler baffle blocking the exhaust.

I also would try replacing the distributor module as that could give symptoms as you describe and is an easy thing to change out before doing other things.

Emery Stora
77 Kingsley
Frederick, CO

>
> Since we purchased a fixer-upper home in Conifer, Co., it has been quite a while since I was able to get back to working on my GMC. When I last
> posted I had just driven my GMC across the country and lost power just as I was passing Denver on the highway. The loss of power was such that I was
> only able to reach a top speed of about 13 miles an hour for the last 20 miles of the drive. Most of the suggestions I was given revolved around the
> fuel filter as the loss of power was not gradual. The consensus was that the filter may have collapsed.
>
> After much delay I was finally able to get the filter out and was dismayed to see that it looked perfect. I put the new filter in along with a new
> battery and fired the GMC up. It ran rough for a bit as it had been sitting for way too long but soon began to smooth out. I had high hopes when I
> backed out of the parking spot. Unfortunately, those hopes vanished immediately as I found that I still had no power. The GMC was barely able to
> make it back up the slight incline to get back to parking spot despite having the pedal to the floor.
>
> I am going to reach out to the local club as well, but was hoping to get as much input as possible toward possible/likely solutions.
>
> Robert
> --
> Robert Peesel
>
> 1976 Royale 26'
>
> Side Dry Bath
>
> Morrison, Colorado
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
 
Emory,

Thanks for the response. I didn't think about the distributor module as I had to replace it on my way across the country. I had to replace the
module when it gave out on me in the middle of Missouri. The message string is here:
http://gmc.mybirdfeeder.net/GMCforum/index.php?t=msg&goto=289253&rid=2027

I will be looking for an extra filter that might exist and will replace the module again. Those are both easy fixes.

Robert
--
Robert Peesel

1976 Royale 26'

Side Dry Bath

Morrison, Colorado
 
If you have a pressure gauge you might just pull the line off the carb and check for fuel/pressure there also. It should tell you if it's a fueling
problem of not.
Hal
--
1977 Royale 101348,

1977 Royale 101586, Diesel powered,

1974 Eagle Bus 45',w/slideout
 
Hal,

That is an interesting idea. What kind of pressure gauge would be used?

Bob

--
Robert Peesel

1976 Royale 26'

Side Dry Bath

Morrison, Colorado
 
> Since we purchased a fixer-upper home in Conifer, Co., it has been quite a while since I was able to get back to working on my GMC. When I last
> posted I had just driven my GMC across the country and lost power just as I was passing Denver on the highway. The loss of power was such that I
> was only able to reach a top speed of about 13 miles an hour for the last 20 miles of the drive. Most of the suggestions I was given revolved
> around the fuel filter as the loss of power was not gradual. The consensus was that the filter may have collapsed.
>
> After much delay I was finally able to get the filter out and was dismayed to see that it looked perfect. I put the new filter in along with a
> new battery and fired the GMC up. It ran rough for a bit as it had been sitting for way too long but soon began to smooth out. I had high hopes
> when I backed out of the parking spot. Unfortunately, those hopes vanished immediately as I found that I still had no power. The GMC was barely
> able to make it back up the slight incline to get back to parking spot despite having the pedal to the floor.
>
> I am going to reach out to the local club as well, but was hoping to get as much input as possible toward possible/likely solutions.
>
> Robert
I have said this before, but maybe not to you specifically: Get a mostly full 5 gallon gas can and run a hose from it through an electric fuel pump to
the input of the mechanical fuel pump on the front of the engine. Power the fuel pump from the cigarette lighter.

If it runs right that way, start your troubleshooting working your way back from the carb to the tanks.

I am still not convinced that you don't have a tank full of crap gas.
--
73 23' Sequoia 4 Sale
73 23' CanyonLands Parts Unit 4 Sale
Upper Alabama
"When I grow up I am going to be a curmudgeon."
 
I missed the earlier discussion, but did someone previously mention the
filter socks in the tanks? Mine were clogged when I bought my coach.

Rick "who got it to work temporarily by applying just a bit of compressed
air back through the fuel hose to push the clogged sock off the pickup
tube" Denney

> Since we purchased a fixer-upper home in Conifer, Co., it has been quite a
> while since I was able to get back to working on my GMC. When I last
>
> posted I had just driven my GMC across the country and lost power just as
> I was passing Denver on the highway. The loss of power was such that I was
>
> only able to reach a top speed of about 13 miles an hour for the last 20
> miles of the drive. Most of the suggestions I was given revolved around the
>
> fuel filter as the loss of power was not gradual. The consensus was that
> the filter may have collapsed.
>
>
>
> After much delay I was finally able to get the filter out and was dismayed
> to see that it looked perfect. I put the new filter in along with a new
>
> battery and fired the GMC up. It ran rough for a bit as it had been
> sitting for way too long but soon began to smooth out. I had high hopes
> when I
>
> backed out of the parking spot. Unfortunately, those hopes vanished
> immediately as I found that I still had no power. The GMC was barely able
> to
>
> make it back up the slight incline to get back to parking spot despite
> having the pedal to the floor.
>
>
>
> I am going to reach out to the local club as well, but was hoping to get
> as much input as possible toward possible/likely solutions.
>
>
>
> Robert
>
> --
>
> Robert Peesel
>
>
>
> 1976 Royale 26'
>
>
>
> Side Dry Bath
>
>
>
> Morrison, Colorado
>
>
>
> _______________________________________________
>
> GMCnet mailing list
>
> Unsubscribe or Change List Options:
>
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
>
 
If not a second fuel filter somewhere along the frame, you also may have an internally collapsed fuel line. Might try to clear the fuel line with
compressed air. Consider using the fuel can idea to get her home, where it might be easier to fix.
Tom, MS II
--
1975 GMC Avion
KA4CSG
 
You should be able to easilly tell if fuel. When it looses power use max throttle to totally depleat the fuel in the carb and turn off the exactly
when you release the pedal to get a " clean" shutoff. Now open the hatch and remove the air cleaner. While shinning a flashlight down the primaries of
the Qjet watch for 2 distinct continuous fuel streams one in each barrrel like a good squirt gun would deliver as you manually operate the throttle
linkage. If the bowl is full you should get about 5 full pumps til the carb bowl ( squirt gun tank) is empty. I suspect you will only get some dribble
and confirm a fuel problem. If you do get pleny of good duel fuel squirts, (unlikely) put the air cleaner back on and hold the accelerator all the way
firmly to the floor while you crank to clear the flooded condition you just created. You should now know if you have a fuel issue or one of the other
issues others have listed above. Everyone always says "fuel filter" in these situations but in my experience that is rarely the case. If the system
was previously clean it doesn't suddenly get dirty. You could have porosity in the rubber fuel lines. In fact if they have not been replaced with
barrier type mutiple wall lines they are most likely bad as the old type lines are not ethanol tollerant and fail in a few short years of exposure.
Very dangerous.
--
John Lebetski
Woodstock, IL
77 Eleganza II
 
Thanks for the ideas John. I have already replaced the 'easily accessible' fuel lines which means, of course, that I have not replaced the lines
above the fuel tanks.

I will try your test when I get back down to the coach.

Bob
--
Robert Peesel

1976 Royale 26'

Side Dry Bath

Conifer, Colorado
 
Robert, don't know if this has already been covered, but, will mention it
anyway if it has not been covered. The electric tank switching valve has a
history of failure with alcohol "enhanced" fuels. Regardless of which tank
is selected, an insufficient amount of fuel flows. Solution for testing is
to plumb around it and see if the engine runs. You will need to block off
the tank you are not using.
Mine failed. The replacement one is resistant to alcohol fortified fuels.
Jim Hupy

> Thanks for the ideas John. I have already replaced the 'easily
> accessible' fuel lines which means, of course, that I have not replaced the
> lines
> above the fuel tanks.
>
> I will try your test when I get back down to the coach.
>
> Bob
> --
> Robert Peesel
>
> 1976 Royale 26'
>
> Side Dry Bath
>
> Conifer, Colorado
>
> _______________________________________________
> GMCnet mailing list
> Unsubscribe or Change List Options:
> http://list.gmcnet.org/mailman/listinfo/gmclist_list.gmcnet.org
>
 
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