well its been doing it for awhile now off and on,i thought it was the cat because it was rattling alot.whats happening is after the car warms up to about 190-200 and i take off it stumbles like crazy it also pops and kinda sounds like a banging.if i nail the gas it will really bog and kinda sit still for a second then bang pop then it will go.the only way it stays running right is when i stay on the throttle.i removed the cat to test it and it made no diffrence as far as helping the problem,all that did was make some nasty backfiring noises.im not sure what the heck is happening to this car the engine light is not on.by the way its a 94 formula.any info would be great.its just crazy how one minute its runs excellent then the next when i want to give it a go it does nothing but make horrible noises and poke along.any ideas?

 

O2 sensors, plugs, wires, opti, coil, ignition control module, clogged injectors, fuel filter.... Could be anything. Start with the cheapest and work your way up. Or get a scanning tool.


Chris

 

if it's only doing it once the engine is warm i would be inclined to think it's ignition related - ignition coil, opti, ICM, plugs/wires.

 

i will give it a shot.i just hate the guessing game.i already have a cap and wires.so i will do those tommorow.thanks

 

what year is the car? If you are OBD-II you could always find someone to scan it and see if individual cylinders are reporting misfires...that would be helpful.

 

its a 94,how can they scan it if it only does it while driving?i will look in to getting it scanned.

 

well if it's a '94 you won't be able to detect misfire anyways. You mentioned it's backfiring too which would indicate timing being out. If you could get it scanned it would help in determining if you are getting a code showing problems with opti signals. However, you probalby have an opti/ICM/coil problem. coils are only like $30 so not a bad thing to change anyways if you can't get anyone to scan it. Otherwise i would say ICM and opti would be next.

 

i put a coil on it a few months ago,and it ran horrible.after i put on a new one it seemed like it was cutting out at lower rpms almost like it had a new rev limit.i work in a parts warehouse and looked into the coil i tryed and found out its used on alot of gm's even geo prizm.so if i decide to get another what brand would be reccomended?i used a borg warner.im going to replace everything coil,icm,plugs,cap,rotor,and distubitor.i hope this solves the problem.thanks for you help

 

I Had An Almost Identical Problem, Replace The Icm Above The Coil And It Will Probably Fix It.