[img]smileys/smiley19.gif[/img]Hi, I am having much problem with my 91 buick century 3.3 v6. I have replaced catalytic conv. O2 sensor, MAF sensor, one other item I cant remember the name of just below the MAF. I fixed a vacuum leak. Also replaced muffler, new sp plugs. all this helped a bunch but now there is still a jerking to it. When I initially step on the gas it sludges out then picks up then at about 35 starts the jerking, funny thing is when I go uphill, it runs perfect. I know it must be getting too much fuel, what could this be? Also where in the world is the EGR


valve? Cant seem to find it!! do you think it could be fuel pressure reg? MAF code still showing up and the code 22. I need this fixed bad and cant afford garage to fix it for me. Just trying to figure it out on my own with my dad. Thanks in advance for all your help!!

In most case the egr vavle look like a mushroom with a vaccum line on
top. In more recent car the EGR valve is electric. This valve take a
part of exhaust gaz an return for a recombustion. If you find it and
want to test just unplug it and test your car.

One thing not mentioned with this diagnosis was the spark plug wires. Spark voltages rise very quickly with load, and can leak spark under very high loads, causing the jerking you describe. Ray

My 92' century does that too, every time I tap the gas peddle it jerks like something feirce. I like it, but my passengers are getting annoyed. Could be because I installed a huge air intake system.


Brumskee


[img]uploads/Brumskee/5Z81B_finish-car.JPG[/img]

Hey Duggie,


I have probably the same 3.3L engine, and can't find a trace of an EGR valve anywhere. Check my latest post on my thread about rough idling.

I agree with the post involving the plug wires, which are prone to problems as they age. From the description of the problem, I would also check the cam and crank sensors, and any sensor used for positioning. I have also seen problems with coils, and modules cause the problems you are experiencing. Please advise if you need procedures. Ray

i had this problem also . i found thst reclining the seat and tilting the steering whe3el seemed to help

On those engines, which are one of the best, when you replace the plugs , REPLACE THE PLUG WIRES TOO. There is no way to get them off without damaging them and if damaged , spark jumps to ground and gives the symptoms you see. They should be replaced ONE AT A TIME. The addl cost is worth not having the aggravation.