1989 Fleetwood Stalling & Surging

[Driftwood]

Anyone have an idea what is causing an '89 4.5 ltr to stall and surge intermittently? Sometimes it runs fine, other times it runs sluggish with no power and eats gas. I changed the fuel filter recently and it help awhile but then started again. I have now dropped and flushed the tank, changed the filter again but with no improvement this time. No codes are registered when my mechanic checked, he has no idea what it may be now. Anyone here have a clue?

[Torqued]

Sounds like it may be a stuck float in the carburetor. Unless you don't have a carburetor, in which case I don't have a clue.

[Driftwood]

It's fuel injected. Throttle body has been cleaned also.

[Torqued]

Does it seem to do this after a long drive when you come to a stop and then try to accelerate? I have an 89 Brougham that did that and it was the torque converter staying locked up due to a sticking solenoid in the transmission.

[Driftwood]

Doesn't matter when. It may do it at cold start, after long drive, or anywhere in between.

[Torqued]

Does it run OK when it's in park or neutral and only mess up when in drive or does it run bad no matter what?

[Driftwood]

Doesn't matter whether in gear or parked. I can start it now and it runs bad, let it run 5 minutes and it will start running fine. Next 5 minutes it may poop out again.

Sometimes it runs so sluggish, I'll have the pedal almost to the floor then it may suddenly start running fine again and take off like a rocket. Good thing I have several other cars as backup!

[Torqued]

I had a Buick that acted similar to that once. The distributor was in front and the fan belt had slowly cut through a couple of the wires (not spark plug wires) going to the distributor. The connection became intermittent and didn't cause a code to set but it would cause the timing to go extremely retarded. When that happened it lost so much power it couldn't get out of its own way. Sometimes it would backfire too. You may have something similar going on with the wiring from the ditributor to the ECM. I'd check all the connectors for loosness and look for anything chaffing on the wires.