Frustrated-Need Help!

:confused: Have cutlass ciera 1988 2.8L. Took in for "scope" and they said it was the temp sensor. Replaced it. Still runs rough and misfires. Did tune up. Replaced Coil packs, fuel pressure regulator, checked vacuum hoses, and replace plenum gasket. Still runs rough-worse with load on engine. No codes blink out now. Also replaced computer. Anyone have any ideas? I can't bring back for another "scope"--no money now. I did all the work myself except for the scoping out. It starts very hard, but once it starts it runs ok while cold. But as soon as it gets warm or I have to slow down or stop, it runs rough and gets worse. Using up a LOT of GAS.

I don't know if you've already solved it, or that my suggestion will be your answer, but my 87 Cutlass misfired like crazy when I first drove it. The problem was my spark plug wires. Check them out, they're inexpensive to replace -

:confused: Have cutlass ciera 1988 2.8L. Took in for "scope" and they said it was the temp sensor. Replaced it. Still runs rough and misfires. Did tune up. Replaced Coil packs, fuel pressure regulator, checked vacuum hoses, and replace plenum gasket. Still runs rough-worse with load on engine. No codes blink out now. Also replaced computer. Anyone have any ideas? I can't bring back for another "scope"--no money now. I did all the work myself except for the scoping out. It starts very hard, but once it starts it runs ok while cold. But as soon as it gets warm or I have to slow down or stop, it runs rough and gets worse. Using up a LOT of GAS.
have you checked your catalytic converter? the way it sounds it might be clogged.

I would say it's either an egr valve sticking shut, or a bad converter.