Problems after Warmup

I have tried a number of things to fix this problem. And Canadian Tire "tried" to fix it, unsuccessfully. Since this car is not in the greatest condition, I wasn't ready to spend $1000 on it, so I'm trying to figure out what is "really" wrong.

The car runs fine before it is fully warmed up. After warmup, it has problems accellerating properly if you push the gas more than very gently.

Canadian Tire claimed that it would be an ignition coil, and the EGR valve. Now, I got them to install used parts for these, and the problem remained exactly the same. I'm not sure if I'm just dumb, but I doubt that even used parts would have *EXACTLY* the same problems.

I am doubting that it's a coil because the car starts fine, no matter what, but from what I can tell from my research, it certainly may be the EGR, but I'm looking for more opinions before I go ahead and order the peice from the US (I can get it for $85 US, instead of $300 CAN).

Thanks for any input.

Welcome to AF, first please post the year, engine and mileage. Describe in more detail what happens, holds back, dies, misfires.

Thanks for the welcome.

You are right in saying that information would be more useful.

92 Lumina Euro 3.1L

The car lurches and jolts when accelerating pretty much at all after the car is warmed up. I don't know if it's "knocking" (not having ever heard what that's like), but it feels "violent" enough to me. I'm not sure how else to describe the symptoms.

Thanks in advance

I'd check fuel, pressure first especially during the problem about 37 psi, then suspect bad plugs and/or wires. This type of problem needs omeone knowledgeable to determine the problem through a road test and basic diagnostic steps.

To add to the information, since this started, I have changed all spark plugs and wires, and also, put in a new PCV valve. As you can see, I've looked into some of the cheaper possibilities.

How would one be able to check something like fuel pressure when something only happens when driving? It's certainly not something that happens while idling. I had read that it could possibly be a bad fuel filter or fuel pump, which is another thing I'm considering.

Thanks for all input.

You can tape the fp gage to the w/s and close the hood then read the gage as you drive, make sure you have a good tight seal when attached to the fuel rail to avoid leaks.