I have a major problem witch I suspect is a vacuum problem. While I'm driving if I put the pedal to the floor the engine dies/miss/sputter for a short moment then run normally. How can I find out if the problem is really related to a vacuum leak. I unplugged the hose coming from the PCV that goes to the charcoal canister and I put a cap on it and it seems to work better (the reason why I suspect a vacuum leak). Could my charcoal canister gone bad? I need to fix this problem ASAP.

Thanks!

 

Sounds like a spark or fuel problem to me. Correct me if I'm wrong, but the only way a vacuum leak would affect the engine is if it lets unmetered air enter the engine, throwing off the air/fuel ratio.

If it sounds like a miss, then I would suggest check the timing and ignition parts like the spark plug wires, cap, and rotor. A lot of times the spark plug wires get close to the headers and they get melted through a little and before you know if they are arcing to the engine and causing a miss.

Does it do this under load? If you put it in neutral can you tell if it is missing? You can put the car in drive and hold your foot on the brakes and tap the gas and listen for hesitation.

Also, if this is TPI, there is a brown wire with a black stripe the runs along the passengers side of the engine compartment, in front of the blower fan. There is a connector there that you can pull apart. This will disable the engine's ability to alter timing, so you can drive the car and see if the computer is screwing the timing up.

Robert

 

Yes it's only doing it under load. If it's in neutral you can't tell if it's missing it run perfectly at any RPM. By the way it's a carburated 305 model (LG4).

The plug wires, cap and rotor have been changed last year so I guess the problem is not there but I will check to make sure.

Anything else???

Thanks!

 

Come on guys I need your help. Anything at this point will be good.

 

Seems like you're not getting any fuel from the accelerator pump n the carb...I'm not familar with these carbs, but...

With the engine off, look down the throat of the carb and open the throttle quickly, you should see gas squirt. If gas squirts, the pump is okay.

Could be a lag in the secondary butterflys opening too?

Try opening them manually, see if the stick at the very beginning of them opening...just press your finger into them.

If it is a carb problem, post up on the Carb board, Ed Maher knows these carbs pretty well.