1992 Grand Prix loses power intermittently!

Vehicle: 1992 Grand Prix SE, 3.1 L Fuel Injected

Problem: I have recently come upon this issue, I drive the car fine when it is cold, but as the car warms up, I seem to loose cylinders intermittently, and the car will start to shudder at certain speeds, and at idle, due to the lack of power. I can push through the loss, at times, and get all my cylinders, but it goes back to the same problem after a few minutes.

At first, I thought it might be the plugs, so I changed those out with the wires. Then, possibly the exhaust, so I changed out the catalytic, and am in the process of changing the mufflers. I’ve checked my ignition coils, and they seem to be alright.

This one really has me stumped, please help!

it could be your fuel check valve is going bad.


It might help to determinine if the problem is fuel by spraying Starting Fluid (or, similar brand) into the intake tube while the engine is idling roughly. If the idle smooths, fuel injector(s) may be at fault.

now i find that it won’t even go above 4000 rpm