1978 Trans-Am keeps stalling need help


86cookiemonster
04-17-2010, 07:13 PM
I have a 1978 Pontiac Trans Am, it has the W72 6.6 liter v8 in it. I have rebuilt the carb, I have cleaned the entire fuel system. It has a new fuel pump, new fuel filter, I just put a new insulated pipe from the pump to the base of the carburator. I have also checked all the vacuum lines. Everything checks out. Yet it still stalls out. It runs perfectly when you first start it up. But once it gets hot it stalls out. Once up to temp it won't restart untill it cools down.

I used some starting fluid just now, and itfired up and idled really rough, then it stalled out. It is like it is not getting gas. I have come to think that the problem is the catalytic converter. The fuel lines run close by it. I put gas in it the other day, and when I took the gas cap off a large amount of vapor gushed out of the tank. My thinking is that the cat is clogged, and is getting hot and evaporating the gas in the line. Is this logical? Or am I missing something curcial?

I need help and quick, my dad is getting sick of it being in the garage and not running right, and is threating to make me get rid of it. It was my grandfathers car so... I really don't want to do that. Help is needed urgently.

MagicRat
04-17-2010, 10:21 PM
Runs bad when its warmed-up?
Classic signs of a bad ignition coil. Imo look at this first.

Also, vapor lock can cause these symptoms..... where the gasoline in the fuel line boils from the heat of the exhaust.
This does not mean there is anything wrong with your exhaust. But a tank full of 'winter' gas (which is more volatile than gasoline sold during warmer weather) can cause this.

wrightz28
04-19-2010, 09:23 AM
Runs bad when its warmed-up?
Classic signs of a bad ignition coil. Imo look at this first. .

Agreed, sounds like the problem is in the ignition system.

86cookiemonster
04-19-2010, 09:35 AM
See I was thinking that too. But it seems to run fine as long as it is not ideling. my dad shot some starting fluid into the carb and it fired right up. So he seems to think that measn it is still a fuel issue. Or is that a red hairing?

86cookiemonster
04-21-2010, 09:12 AM
Agreed, sounds like the problem is in the ignition system.


Just curious how do you check for a bad ignition coil?

86cookiemonster
04-24-2010, 05:39 PM
okay I replaced the ignintion control moduel, I replaced the coil, I put a new cap and a new rotor on it. It has a new fuel pump and I am positive it is getting fuel to the pump. I am in serious trouble here, what could the problem be? I am running out of things to fix.

wrightz28
04-26-2010, 09:27 AM
Didyou replce the module with an A/C delco one?

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