Hesitation

walter drew

New member
Nov 23, 1999
28
0
0
Need your collective help!

Just completed a trip from Santa Fe, NM to Monterrey, CA and back in eight
days. Coach ran well going out, but filled up with mid-range gas in
Salinas, CA for two bucks a gallon. When I go down to sea level the engine
runs better on higher octane gas. That afternoon the engine started
stalling, especially in intersections and busy areas. It would always
restart, so I pulled the fuel filter, it was clean. I set up the idle
adjustment and took off the next day. Went to Carmel and had some minor
problems with stalling, but it seemed to be running better. Carmel is not a
great place to drive around in a GMC. The parking lots to the right take
RV's, not the one to the left.

After I used that tank of gas which I figured was bad, I bit the bullet and
filled up with $2.20 high octane. Ran better, stayed in Modesto with
in-laws for three days, put in new plugs, and headed home. Drove for three
hours, filled up with mid-range gas in Bakersfield and my wife took over at
the wheel. Got about thirty miles east of Bakersfield and she said, "This
thing won't go." I took over and limped along at thirty five on a slow
uphill grade. Finally crested the hill and got back up to 65-70. Same
story all the way to Barstow. Into Auto Zone and bought a can of gas
treatment and carb cleaner. Ate lunch and took off. Now she was running
strong. Drove to Kingman by keeping the pedal to the floor until I got up
to 65. If I rode it gently, it would just crap out. Then I would floor it,
it would hesitate and then it felt like the secondaries were kicking in and
off it would go. No more stalling. Next morning I cleaned the carb again.
It was better, but still hesitated on acceleration. Two hour snow storm
east of Flagstaff. By the time we got to Albuquerque it was running strong
again. Hardly step on the gas and it would hold 65 like always. I figured
my woes were over, but on the road to Santa Fe, there is a big grade of
about 700 feet in two miles. Usually I can handle that at 45. I was down
to thirty with my foot through the floorboard.

Any thoughts would be greatly appreciated.

Walter
78 Royale 455, HEI

 
Did you look at the little filter on the Carb where the gas line goes into
the carb ?? A hidden filter if you don't know about it.

gene

>Need your collective help!
>
>Just completed a trip from Santa Fe, NM to Monterrey, CA and back in eight
>days. Coach ran well going out, but filled up with mid-range gas in
>Salinas, CA for two bucks a gallon. When I go down to sea level the engine
>runs better on higher octane gas. That afternoon the engine started
>stalling, especially in intersections and busy areas. It would always
>restart, so I pulled the fuel filter, it was clean. I set up the idle
>adjustment and took off the next day. Went to Carmel and had some minor
>problems with stalling, but it seemed to be running better. Carmel is not a
>great place to drive around in a GMC. The parking lots to the right take
>RV's, not the one to the left.
>
>After I used that tank of gas which I figured was bad, I bit the bullet and
>filled up with $2.20 high octane. Ran better, stayed in Modesto with
>in-laws for three days, put in new plugs, and headed home. Drove for three
>hours, filled up with mid-range gas in Bakersfield and my wife took over at
>the wheel. Got about thirty miles east of Bakersfield and she said, "This
>thing won't go." I took over and limped along at thirty five on a slow
>uphill grade. Finally crested the hill and got back up to 65-70. Same
>story all the way to Barstow. Into Auto Zone and bought a can of gas
>treatment and carb cleaner. Ate lunch and took off. Now she was running
>strong. Drove to Kingman by keeping the pedal to the floor until I got up
>to 65. If I rode it gently, it would just crap out. Then I would floor it,
>it would hesitate and then it felt like the secondaries were kicking in and
>off it would go. No more stalling. Next morning I cleaned the carb again.
>It was better, but still hesitated on acceleration. Two hour snow storm
>east of Flagstaff. By the time we got to Albuquerque it was running strong
>again. Hardly step on the gas and it would hold 65 like always. I figured
>my woes were over, but on the road to Santa Fe, there is a big grade of
>about 700 feet in two miles. Usually I can handle that at 45. I was down
>to thirty with my foot through the floorboard.
>
>Any thoughts would be greatly appreciated.
>
>Walter
>78 Royale 455, HEI
>
>
>
Genef -- 77PB/ore/ca
GMC MOTORHOME INFORMATION
mr.erf
http://www.california.com/~eagle/
 
Walter,
Just an guess, but did you check the module on the HEI? I had a bad one
in my old 454 pu and it acted almost he same. You would swear it was
bad gas, but every thing look good. Were the plugs dark or black?
- --
J.R. Wright
GMC GreatLakers
77 Eleganza II
Michigan

>
> Need your collective help!
>
> Just completed a trip from Santa Fe, NM to Monterrey, CA and back in eight
> days. Coach ran well going out, but filled up with mid-range gas in
> Salinas, CA for two bucks a gallon. When I go down to sea level the engine
> runs better on higher octane gas. That afternoon the engine started
> stalling, especially in intersections and busy areas. It would always
> restart, so I pulled the fuel filter, it was clean. I set up the idle
> adjustment and took off the next day. Went to Carmel and had some minor
> problems with stalling, but it seemed to be running better. Carmel is not a
> great place to drive around in a GMC. The parking lots to the right take
> RV's, not the one to the left.
>
> After I used that tank of gas which I figured was bad, I bit the bullet and
> filled up with $2.20 high octane. Ran better, stayed in Modesto with
> in-laws for three days, put in new plugs, and headed home. Drove for three
> hours, filled up with mid-range gas in Bakersfield and my wife took over at
> the wheel. Got about thirty miles east of Bakersfield and she said, "This
> thing won't go." I took over and limped along at thirty five on a slow
> uphill grade. Finally crested the hill and got back up to 65-70. Same
> story all the way to Barstow. Into Auto Zone and bought a can of gas
> treatment and carb cleaner. Ate lunch and took off. Now she was running
> strong. Drove to Kingman by keeping the pedal to the floor until I got up
> to 65. If I rode it gently, it would just crap out. Then I would floor it,
> it would hesitate and then it felt like the secondaries were kicking in and
> off it would go. No more stalling. Next morning I cleaned the carb again.
> It was better, but still hesitated on acceleration. Two hour snow storm
> east of Flagstaff. By the time we got to Albuquerque it was running strong
> again. Hardly step on the gas and it would hold 65 like always. I figured
> my woes were over, but on the road to Santa Fe, there is a big grade of
> about 700 feet in two miles. Usually I can handle that at 45. I was down
> to thirty with my foot through the floorboard.
>
> Any thoughts would be greatly appreciated.
>
> Walter
> 78 Royale 455, HEI
>
>
 
I see someone else suggested the ignition module, I second that. I had the
same thing go wrong in my car.It stalled out of the blue and started right
up at first. I tried to ignore it, but it got worse. It would start perfect
when cold, but it seemed the hotter it got (traffic, lights, idling) the
more it stalled. I'd check this out.

Tony

- ----- Original Message -----
From: Walter
To:
Sent: Wednesday, March 22, 2000 4:58 PM
Subject: GMC: Hesitation

> Need your collective help!
>
> Just completed a trip from Santa Fe, NM to Monterrey, CA and back in eight
> days. Coach ran well going out, but filled up with mid-range gas in
> Salinas, CA for two bucks a gallon. When I go down to sea level the
engine
> runs better on higher octane gas. That afternoon the engine started
> stalling, especially in intersections and busy areas. It would always
> restart, so I pulled the fuel filter, it was clean. I set up the idle
> adjustment and took off the next day. Went to Carmel and had some minor
> problems with stalling, but it seemed to be running better. Carmel is not
a
> great place to drive around in a GMC. The parking lots to the right take
> RV's, not the one to the left.
>
> After I used that tank of gas which I figured was bad, I bit the bullet
and
> filled up with $2.20 high octane. Ran better, stayed in Modesto with
> in-laws for three days, put in new plugs, and headed home. Drove for
three
> hours, filled up with mid-range gas in Bakersfield and my wife took over
at
> the wheel. Got about thirty miles east of Bakersfield and she said, "This
> thing won't go." I took over and limped along at thirty five on a slow
> uphill grade. Finally crested the hill and got back up to 65-70. Same
> story all the way to Barstow. Into Auto Zone and bought a can of gas
> treatment and carb cleaner. Ate lunch and took off. Now she was running
> strong. Drove to Kingman by keeping the pedal to the floor until I got up
> to 65. If I rode it gently, it would just crap out. Then I would floor
it,
> it would hesitate and then it felt like the secondaries were kicking in
and
> off it would go. No more stalling. Next morning I cleaned the carb
again.
> It was better, but still hesitated on acceleration. Two hour snow storm
> east of Flagstaff. By the time we got to Albuquerque it was running
strong
> again. Hardly step on the gas and it would hold 65 like always. I
figured
> my woes were over, but on the road to Santa Fe, there is a big grade of
> about 700 feet in two miles. Usually I can handle that at 45. I was down
> to thirty with my foot through the floorboard.
>
> Any thoughts would be greatly appreciated.
>
> Walter
> 78 Royale 455, HEI
>
>
>
 
> Walt - I had reported a couple of weeks ago that I had a similar
> problem
> coming across lower Louisiania on the way to Florida. It would bog
> down to
> about 55 on small hills but would run at 65 on level ground. I
> replaced the
> fuel filter and then my O2 probe (on TBI fuel injection). Nothing
> helped.
> Finally replaced my module in the distributor which was only a few
> months
> old, and the problem went away.
>
> Lets get together when I get back to Santa Fe in a couple of weeks.
>
> Emery Stora
> 77 Kingsley
> Santa Fe, NM

I would like to add (from my experience)............be sure to get a
branded ignition module. There are many knowck-offs of the Delco product
that are being made in places like Timbucktoo and they are not reliable.
Also, carry a spare (it will probably never fail, if you do!):)

David Lee Greenberg
GMC Motorhome Registry
Dedicated to the preservation of the Classic GMC
http://www.gmcss.com/registry.htm