Hot start problem, not the starter

[Chas Henderson #28127]

My 71 sb auto starts up fine and the engine runs well. When I let it sit for a while after a drive, the car will turn over and fire, but it seems to act like its starved for fuel. Now, this is a hit or miss problem as most of the time it will run fine. But when it does do t, it dies. I can restart it, but I have to pump the gas pedal and rev her up a few times after I get her going. Once I get going again it will run just fine. The engine is all original. I have the timing and gap correct, plugs look good, nice and ashy colored. New fuel filter element, C.E.C. working ok. Idle set correct, and the fuel pump seems to work O.K. The carb is the only thing I don't feel really good about. Is the car evaporating the fuel in the carb while it sits? If so does that mean I have a float problem? I had the carb rebuilt 6 yars ago. Time for a rebuild? Anything I can try first?

Thanks,
Chasman

[Jim T.]

Re: Hot start problem, not the starter

Q-JET carbs have plugs on the bottom that can leak fuel out of the fuel bowl if given enough non driving time. I had this problem with my 70 during its early life. Put a Holley spreadbore double pumper on it in 1973 and if the car sat for three days it would fire right up. Fuel in Holley's will evaporate if the car is not driven for a long time, however it is so easy to fill the fuel bowl with a big syringe pumping fresh fuel through the verical bowl vent that the car will crank right up after it has been sitting, saves unnecessary wear on the starter. If your Q-Jet is leaking, it can be repaired.

[Jack H.]

LT1 Engine Used Holley Instead Of QJet.... *NM*

[Mike McKown]

I've been driving Quadri-jets ever since they

came out. Let them sit for several days and they won't start until you will the float bowl up with a little cranking on the starter and a little pumping on the gas pedal. I hate those things (quadri-jets).

No need to raise the hood and use your syringe to squirt gas in the bowls. All this does is wear out the hood cable and then it will break and then you wonder how to get the hood open. Same with the threads for the wing nut on the air cleaner.

Crank it over about twenty times, pump the gas three or four times and it outa' fire.

I think this problem is worse today on the cars that have vented float bowls than those that don't.

[Chas Henderson #28127]

Re: I've been driving Quadri-jets ever since they

The problem happens just after a drive, with a short stop. Some people have hot start problems with the startwe, my engine turns over and fires, but it has a tendency to die and I have to fire it up again and the sit and rev the engine to keep it running. Once I start to drive it, it seems to run fine. It is an original rodchester carb #7041212_I think.

Chasman

[Mike McKown]

Re: I've been driving Quadri-jets ever since they

A guess only. Without hearing it run, I'd guess you have a float taking on gas and flooding the engine. If you condition worsens and you have black smoke out the exhaust, I'd bet on it.

[bruce11495]

Re: I've been driving Quadri-jets ever since they

Chas....Classic "heat sink" problem. Holleys (LT1s) are notorious for this problem. Maybe the car is running a bit hotter than usual, hot summer this year, etc. I would not expect it to be a bad float if it ONLY happens when its hot,if its a bad float it will have a starting problem cold too.