The tachometer on my 92 camaro V6 is not steady at idle and fluctuates a great deal on acceleration. Also, when the trans shifts to overdrive (700R4) to around 1500 rpm at 50 MPH, the car noticeably hesitates continously but is able to maintain speed. I'm suspecting the fuel pump, I've done easy stuff so far (air filter, fuel filter) but nothing's helped. Are there other things I need to look at besides the fuel pump? What troubleshooting can I perform on the fuel pump to see if it is working correctly?

 

With the symptoms I would be more inclined to check the ignition system. Plugs, wires, cap & rotor. Then possibly the distributor pickup coil. The fluctuating tach is the best symptom that points to ignition.

RBob.

 

Check your plug wires, one of them may have come off.

 

I'd also check your grounds and make sure they are tight.

Had similar symptoms and it turned out the ground wires on my intake were loose.