Pontiac Owners Club UK

Hi chaps I took my car on its first journey today and when I pull up to traffic lights or a roundabout as soon as I rev to pull away she dies. restarts fine and then ok until I stop again..any suggestions.

Car is an 84 trans am with a rochester quadrajet carb.

Regards

Steve

wow no one seen this problem before?..

steveoooo1 wrote:Hi chaps I took my car on its first journey today and when I pull up to traffic lights or a roundabout as soon as I rev to pull away she dies. restarts fine and then ok until I stop again..any suggestions.

Car is an 84 trans am with a rochester quadrajet carb.

Regards

Steve

This sounds like it may be a problem with the accelerator pump. When the throttle valves first open when you try to move off from a stop there is an in-rush of air and the accelerator pump is supposed to meter extra fuel into that "raw" air to compensate for the inherent lean condition. If the accelerator pump is not working correctly, then the in-rush of lean air will be causing the car to stall. Usually a rebuild is required on the carb to sort this.

The accelerator pump components can be replaced on their own, but to get at it you need to take the top of the carb off anyway so new gaskets will be required as a minimum on top of the accel pump bits.

Start your cars engine and allow to run for a few minutes. Then stop the engine and remove the air filter assembly. if you look into the carb bores and operate the thorottle linkage you should see fuel being squirted into the bore. If not, then this again points to accel pump.

Cheers guys

The carb itself looks quite new/recond.

Wheres a good place to buy these bits?

Cheers

Robin at Autopontiac for tech. advise and parts or Martin at Ultimate Spares of America. Contact details are on the sponsors page.
Sorry for the delay in answering Steve, maybe everyone was Christmas shopping.

Id check all the vacuum pipes too for splits or come off, thay would cause your problem too

If the Rochester has wires going to it then this is a computer controlled carb and can be quite complex.
Does it restart easily and idle ok until you touch the accelerator.
can be a variety of problems would really need to see the car for a proper diagnoses.

Hi robin

There is wires going to the carb yes.

It restarts fine and will then run. Its only when i come to a stop at say traffic lights it will then stall as soon as soon as i accelarate.

There are 3 wires at the front,2 on top and one on the passenger side, if thats correct then its an ECM controlled mechanical carb. sounds like it could be flooding or the accelerator pump is not working properly. Either one would need carb to be stripped
and gone over, if it was here i would do this and then set it up using the analyser to tune it. If it stops when you accelerate what do you do to carry on driving.

I have to restart and then its fine until I pull away again from a standing start. I must add that now it is doing it whilst idling in park. If i rev it chokes and stalls. always starts on first go though. I will have a look tomorrow at the wires. cheers Robin

Steve

this is what mine was doing but not as bad. Had mine rebuilt and it was fine afterwards. Mine is a 100% mechanical Quadrajet though.