Community Forums

Ryan7361 · 06-13-2015, 05:07 AM

I have a 1987 Establishment P30. It will start and run, but as soon as I take my foot off the gas it stalls out. It started during a trip when I began to lose power going up a hill. Things got better after the hill, but 2 or 3 hills later we stalled on the side of the road and had to be towed home. It's a chevy 454
I've replaced all the:
-fuel filters
-and put in a new mechanical fuel pump.
-sprayed "gum out" into the carburetor
I put in a new electric fuel pump and replaced ALL the rubber fuel lines(supply and return), and I even got a new gas cap and checked the vent line! I also replaced the pressure regulator!! It still stalls at idle! Time to check out the carburetor? alternator???

redtail · 06-13-2015, 06:04 AM

I am digging deep here but if memory is correct they used to put a electric solenoid on the idle arm that raised idle speed if AC was on. that is a possibility or a plugged idle jet . also check your vacuum pressure it is high at idle and a small leak will lean the mixture out and cause problems I think it should be around 16 in vacuum Mike

Motor7 · 06-13-2015, 06:30 AM

I'm thinking clogged jets in the carb. A Quadrajet is not an easy carb to work on, so find a "expert" and maybe get it cleaned/rebuilt. Or, you might just want to replace it with a "aftermarket re-built" Quad, or a New Eldebrock. I can't recommend a Holley....they drink a lot of fuel.

Here is a pretty good thread on your carb options;
New Carburetor Choice Advice Wanted Chevy 454

Ryan7361 · 06-13-2015, 08:16 AM

It's going to take a while for me to work through all the vacuum lines(I managed to find a diagram)-I'm noticing that several lines run to the fuel canister(vapor canister?). Could there be troubles in the canister?

James Sinsel · 06-13-2015, 09:30 AM

Ryan check your cat converter for being stopped up. Drop your exhaust pipes from
manifold. Drop about 1 inch.

Jim Sinsel, Baltimore, MD.

89sandman · 06-13-2015, 10:47 AM

When the engine is running is it running smoothly or does it run rough like its missing on a cylinder or two? Have you checked to see if the choke is opening, checked the oil for water contamination? If you do replace the carb don't waste your time rebuilding yours or buying a rebuilt. A almost 30 year old carb has served its time and should be replaced with a brand new unit. Edelbrock or Holley both make carbs that will fit your unit for around $300.

Ryan7361 · 06-14-2015, 06:17 AM

Quote:

Originally Posted by redtail

I am digging deep here but if memory is correct they used to put a electric solenoid on the idle arm that raised idle speed if AC was on. that is a possibility or a plugged idle jet . also check your vacuum pressure it is high at idle and a small leak will lean the mixture out and cause problems I think it should be around 16 in vacuum Mike

I found the "idle stop solenoid" and it's not even wired! It's as if the previous owner by-passed it. I guess I'll have to dig for a wiring diagram............

Ryan7361 · 06-14-2015, 09:15 AM

As I go through all these vacuum lines(they're everywhere), I'm finding lots of cracks and splits in the rubber, so I'm going for a 100% replacement.
Is the vacuum created by a pump or by the engine itself?

Fl_Richard · 06-14-2015, 07:18 PM

Engine. I believe there is a vacuum plate at the bottom of the carb where it starts.

Ryan7361 · 06-20-2015, 03:27 PM

I've noticed my single air door on my carb stays wide open all the time-right down to idle. That can't be right can it?

HoneyBadger · 06-20-2015, 03:44 PM

Quote:

Originally Posted by Ryan7361

I found the "idle stop solenoid" and it's not even wired! It's as if the previous owner by-passed it. I guess I'll have to dig for a wiring diagram............

My 1989 shop manual for the P30 says the idle stop solenoid on the Quadrajet is only for manual transmissions- is that what you have?

Vacuum leaks absolutely will cause your engine to die and/or not run under load. Besides replacing all the vacuum lines (the most important one is going to the vacuum advance on the distributor) , you need to check if you have a bad gasket under the carb.

One quick way to check for vacuum leaks is to take a can of WD40 and with the engine running, spray around the base of the carb and along the various vacuum lines. If the rpms change, you have a vacuum leak.

HoneyBadger · 06-20-2015, 03:46 PM

Quote:

Originally Posted by Ryan7361

I've noticed my single air door on my carb stays wide open all the time-right down to idle. That can't be right can it?

Except when it needs to run richer, it should be open.

gman69 · 06-21-2015, 08:51 AM

On my 1997 34' Bounder, it had two fuel pumps. the mechanical one on the motor, and an electric near the fuel tank in a side compartment. The mechanical pump wasn't able to pump fuel all the distance, so Fleetwood added the electric one. Had lots of problems with factory installed Carter electric pump. I finally replaced with a Holley electric pump with a regulator and I never had a problem again.

Ryan7361 · 07-09-2015, 06:11 AM

UPDATE:
I have my ship back! In the end, I broke down and got a new carburetor from NAPA, and it runs great. I had a local old-school mechanic put the new one in for me. In the final analysis, I had a bad in tank fuel pump and a clogged 30 year old carburetor. How could both happen at the same time? Maybe the failed fuel pump sent a bunch of garbage to the carb? Anyway, I'm thinking about putting in one of those fuel filter/water separators like this one Dutton-Lainson Company - Since 1886
Any thoughts? I'm just looking for ways to keep things as clean as possible.
Also, I need to change the oil. How much oil does a 7.4L 454 V8 take?