'88 Park Ave stalls while driving

I'm a delivery driver and use my '88 for work. It's the third one I've had. The first one I got in 1994 and it ran well into 2000 before I retired it with 268,000 miles. This one only has about 124,000 miles and I figured it would last for quite some time, but now I'm not so sure. It's developed a stalling problem but has not set an error code. I have a code reader, and discovered that the fuel system is running in open loop. It stalls mostly at low speeds either forward or reverse, but also stalls on exit ramps or turning. It always starts right back up again without problem.I replaced the ECM, the plugs and wires, and the ignition module and coil pack. I'm thinking now that it's a fuel delivery problem, so I'm having the fuel filter changed this Friday, Dec. 9. The mechanic doing that job told me it probably wasn't the fuel pump or relay, because they're either good or they don't work at all. If the fuel filter doesn't fix it, I'm considering buying something else. Anybody have any ideas? It seems to be a tough thing to diagnose.

If the ECM is contantly running in open loop then something is wrong forcing it into defaul or limp mode. Sounds like it could be a torque converter clutch flailure

Thanks for your reply! That would make sense because ever since I got the car, it would stutter if you gave it too much gas from a stop. If you depressed the accelerator gently, it would be fine, so I just put up with it. Is it something that can be reasonably repaired, or would the transmission need to be replaced?

You can disconnect the solenoid and loose a few MPG because you will loose the lock up feature for now. This will also prove if the theory is correct. It's the first thing that comes to mind when stalling at stop, but there are other possiblities, but I'd go this route first if it were me. What does your MPG run?

The trans on these is pretty easy to do maintnance on, in the car :D

The MPG on this car has never been what it should. I do alot of starting and stopping, and it averages around 20-22. On the hioghway, it only gets around 26 or 27. The first one I had got over 30. But it's worth a try to disconnect the solenoid. Where is it located and how is it disconnected?

I believe on the backside, green or orange wire, can't remember off the top of my head right now.

Opposite the vac. modualotr?

Decel Stall or Long Crank On Start-Up
Bulletin: 93-6E-3
Date: Oct.1992
Ref. No.: 93-6-6E
SUBJECT: New Idle Air Control (IAC) motor for 3800 and 3300 engines
MODELS AFFECTED:
• 1988-90 Electra/Park Avenue, Riviera/Reatta And LeSabre Equipped With 3800 (VIN C) Engine.
• 1991 LeSabre Equipped With 3800 (VIN C) Engine.
• 1989-93 Century And Skylark Models Equipped With 3300 (VIN N) Engine.
• 1990-93 Park Avenue, LeSabre, Riviera/Reatta And Regal Models Equipped With 3800 (VIN L) Engine.
• 1991-93 Park Avenue/Ultra Models Equipped With 3800 S/C (VIN 1) Engine.
Some of the models mentioned above may experience a decel stall or long crank on startup. This condition can sometimes be viewed on a scan tool as excessively high IAC counts at idle immediately after startup, or as a failure to return to the same (or similar) IAC counts displayed at idle after several throttle maneuvers.
If this condition is experienced and currently published service diagnostic procedures indicate a malfunctioning IAC motor, it will be necessary to install a new IAC motor.
It should be noted that two designs of IAC motors exist. The 3800 (VIN L) and the 3800 supercharger (VIN 1) use a triple slope design. The 3800 (VIN C) and 3300 (VIN N) use a dual slope design. The dual slope and the triple slope designs are not interchangeable. Several part numbers for IAC motors are being phased out to standardize usage and are being replaced by current production IAC motors.
The chart below lists the application and appropriate service part numbers.

Year Model Engine VIN Code IAC Part #
1988 to1990 Electra, Park Ave, Park Ave Ultra, Riveria, Reatta, LeSabre 3800/LN3 C IAC Part #17112650

1991 LeSabre 3800/LN3 C IAC Part #17112650

1989 to 1993 Century, Skylark 3300/LG7 N
IAC Part #17112650

1990 Regal 3800/L27 L IAC Part #17112649

1991 Park Ave, Park Ave Ultra, Riveria, Reatta, Regal
3800/L27 L IAC Part #17112649

1992 to 1993 Park Ave, LeSabre, Regal
3800/L27 L IAC Part #17112649

1991 to 1993 Park Ave, Park Ave Ultra 3800 SC/627
1 IAC Part #17112649