Chevrolet Repair: 94 z24 cavalier convertible, head gaskets, pan gasket

Question
The most recent work that i've had done to the car was back in february.  I had a fuel pump replaced, oil gage sensor, new intake (it was cracked) new O2 sensor, new exhaust, new head gaskets, new temparature gage, oil pan gasket (i think that's what they called it), and a complete tune up.  Does that help any?

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Followup To
Question -
Hopefully you can help me as no one else seems to know what's wrong with my car.  After driving it for about 20 minutes the rpms will start going crazy like my car is surging and then thinking about stalling but it happens very quickly.  If I put the car in neutral the problem seems to stop.  If I pull over put it in park it will either calm down and idle normally or it will stall.  I've been told fuel filter to vacume hose leak but no one is sure and tells me that they are just guessing.  Let me know if you have any ideas or any questions.
Thank you so much!
Answer -
What mechanical work or ANY kind of work has been performed on the vehicle recently ?. As most problems that occur after a recent repair was made can be traced back to the area of where the repair was made as a vacuum line may have been knocked loose or a wire connection came loose, Look around in the area where work was performed.

There are just SO MANY possibilities that can cause this fault that it is all that anyone can do is GUESS unless there are extensive diagnostic procedures performed on the vehicle.

I honestly wish I had the answer for you, But with the complexity of today's electronics this will require extensive diagnostic procedures performed by a qualified technician.


autohelp

Answer
With all this previous work, It is highly possible that one of the repairs may have been performed incorrectly and one of the intake and or head gaskets may have a problem.

Your vehicle can be repaired, But it is going to take some well qualified expertise in performing numerous diagnostic test procedures to find the answer.

I would love to be able to give you the answer your looking for but it is just impossible unless I had personal access to the vehicle to be able to perform the necessary test procedures.

Your pretty well stuck to try and find a reputable facility who would take on such a project.

Without having the vehicle at my shop, All I could do is guess and I am NOT into GUESSING.


autohelp