1993 LeSabre, Rough Idle, Poor Acceration

[JayPower95]

I have a 1993 LeSabre Limited with a 3800 Series I. Recently I have been experiencing poor acceleration and an intermittent rough idle. I have replaced the following:

Fuel Pump,
Sending Unit,
Trans Vacuum Modulator,
Mass Airflow Sensor,
Fuel Pressure Regulator,
Intake Manifold Gaskets,
Spark Plugs and wires,
Tested coil packs (All work),
EGR,
Vacuum Lines,
and Air Filter.

When I bought the car it ran ok, it just had a bad fuel sending unit (The gas gauge always read full) so I had the fuel pump replaced while the mechanic was in the gas tank just for good measure. The car ran fine. I replaced the spark plugs later and it started misfiring and I soon realized that one was loose (I made a goof). I fixed it and the Car ran ok. Recently it started idling weird and has low power
while accelerating. After troubleshooting and replacing over $400 worth of parts ( Mass Airflow Sensor, Fuel Pressure Regulator, Intake Manifold Gaskets, EGR, and Vacuum Lines) it still acts weird. After replacing the Fuel pressure regulator and intake manifold gasket it seemed to help a small bit, but still doesn't perform as it should. I am frustrated and at a loss for what to do, I am worried that eventually it will turn into something worse and I really can't afford to do anymore to it

Any ideas or advice?

Thanks,
-Jon

 

[Lubener]

You present a good case for systematically testing and not to guess and throw parts at it. Did you check for codes? Hang a vacuum gauge on it, is it at 18-22 inches, steady at idle? Accellerate, does the vacuum fall down and stay low indicating a blocked converter? Hang a fuel pressure gauge on it. Is fuel pressure at specs or do you have a blocked filter, restricting flow? A new, no name fuel pump could be operating marginally. How are the plugs burning? Curious how you tested coil packs? Check out and update us.