stahrman0612

I have a 1986 Pontiac Trans-Am. It has a 305 4 bbl.(engine code H). The car runs flawlessly after it is warmed up. The electric choke is working like it is supposed to. The last few years, it has been getting harder and harder to start after sitting overnight. It started out needing 3-4 pumps with occasional dying after the first try then starting right up....then last year was 5-8 pumps. Now I have to pump 20-30 times with occasional dying after first try. I believe maybe the fuel well is draining completely(tip from Sonix) and that is why I have to pump so much? I was told there are some plugs at the bottom of the well that will start leaking over time? Will a rebuilt carburetor solve this problem? Is this separate from a rebuild? Can I go to a local shop and just have that part of the carb rebuilt and fixed? The car only has 108,000 miles (family owned since new) and has been stored every winter for the past 30 years and has been well taken care of. Any suggestions appreciated!! Ps....does this year Trans-Am have the E4ME or the E4MC??

naf

iTrader: (7)

E4ME unless it's an export mode. (the E4ME will have a three wire connector front/left on the carb).

could be leaking or the booster pump is weakening. booster pump failure will normally manifest itself as a driveability problem, it will stumble when given a good throttle opening.

you can look for a good booster shot by peering into the primaries and looking for a fuel squirt when the throttle is opened quickly. should be the same hot or cold. no booster shot when cold may indicate a low fuel level within the carb.

you can then remove the carb and let it sit while full over something that will show any fuel leakage, like a clean shop towel.

with the carb's age a rebuild may be in order anyway to freshen all of the soft parts. when stored over the winter the gas in the carb likely has a chance to get old and cause problems.

your issue could also likely be a choke adjustment issue.

I'd check for fuel with the booster shot, spray down all of the choke linkage and observe everything for proper operation. make sure the choke pull off functions as it should.

stahrman0612

"could be leaking or the booster pump is weakening. booster pump failure will normally manifest itself as a driveability problem, it will stumble when given a good throttle opening." Is the booster pump another name for the accl pump?
"your issue could also likely be a choke adjustment issue.
" Electric choke seems to be working fine as long as I have enough gas to keep it running.....choke pull off has good vacuum. I'll check with the other things that you mentioned as soon as I can. Thanks naf!!

1987L69

Yes the booster pump is another word for the accelerator pump, I had the same issue with a 74 Monte Carlo I used to have with the original LS4 454 in it. It took forever to get it to start, tore down the carb and sure enough, the plunger had dried up and slipped off the rod. After a rebuild it was good as new. I would start with a good rebuild before messing with the choke settings, just take your time, take pictures, and its very easy!

stahrman0612

I have been talking to Cliff Ruggles from Cliff's high Performance and he thinks my bottom (well) plugs are leaking. He also suggested to change out accl pump. Here is what he told me:...... Never buy a "rebuilt" carburetor, correct repair and fix the original. It may be leaking from the bottom plugs and emptying the bowl, but most likely the fuel has also ruined the accl pump as well, so I would replace all the internals while the carb is apart for repairs.....Cliff
Oh and thanks 1987L69

1987L69

Some rebuild kits I have gotten in the past have a small rubber piece that the instruct you to epoxy to the bottom plugs, others ive gotten dont have it, but either way I would put some JB weld on the plugs. and yes Cliff is right, dont get a rebuilt one from a parts house or JET performance, about 50% of them are junk out of the box that I have seen. I only rebuild Q-jets that have not been "re-manufactured" by an outside company, there was a guy on the Corvette Forum I used to be on that was very VERY good at rebuilding factory Q-jets, he charged about 300$ but from what his reviews were it was worth every penny!

stahrman0612

I don't feel comfortable taking apart the carb, so I think I'm gonna see if a local shop can do the repairs on it.....if that doesn't work out, I'm a two hour drive from Mount Vernon Ohio. I'll have Cliff work on it. He said he does things like that for locals on the weekends.

stahrman0612

What about the mechanical fuel pump in the engine bay (not the in-tank one). I've read somewhere that it could have a bad seal and the gas siphoning out of the carb? Could that be a possibility??

1987L69

There is a weep hole on the mechanical fuel pump, if its going out you will be getting fuel or oil out of it, or you will be getting gasoline in your oil. I would just take it to Cliff and be done with it, he can set up everything for you and you wont have to touch anything on it and not have to worry about anything for many years to come!

stahrman0612

That is probably what I will end up doing. Thanks 1987L69

stahrman0612

*UPDATE* I took my T/A to a local garage last week, it ended up being my choke pull-off needing adjusted. I couldn't believe that was all that was wrong with it? I let it sit for 2 days.....pumped the gas 2 times......she fired right up to high idol!! So glad it wasn't the carb. Roger said for a 30 year old car with the original carb it was in immaculate condition!! Thanks for everyone's help!!!

zed-028

Glad you got it solved. If you ever need to to a rebuild on the carb its actually pretty easy. the kits have everything and its about an hour and a halfs job tops.