93 Bonneville Engine Surging

[Rick V]

Hello.

I really need some advice. I have a 93 Bonneville SE with 180K miles. A while back, the service engine light came on and the engine would start surging. While sitting at a light, the surging caused the trans cooler line to disconnect, spilled all the fluid and I lost the tranny. Had it replaced but the light still comes on and engine still surges, though not as much. When light comes on, car won't shift into OD and cruise control doesn't work. Sometimes car stalls at a stop but will start right up. When light goes out, car will shift in OD and cruise control works. Also, when light is not on, trans shifts at about 3,000 rpms. When light is on, trans shifts right under 2500 rpms. When I first start the car and engine is cold, runs fine. But then the engine revs up to almost 3k rpms and slows down. Does this for a couple of minutes. Any expert advice is greatly appreciated. Want to take car to a trans shop but I need to be well informed before I spend more money on this.

[maxwedge]

Welcome to AF, you seemed to have skipped the basics here, what is the code?

[Rick V]

Sorry maxwedge. I haven't run any diagnostics code scanner on the car since I had the tranny swapped out. I had a friend plug one of those handheld scanners in when the problem first surfaced but he couldn't figure out what the problem was. He mentioned the fuel pressure regulator and I replaced that. Needless to say, that didn't fix it. I don't know if I'm answering your question properly. By OD i mean overdrive.

[maxwedge]

You must get the current code or get it to a pro, we cannot progress any further here without that info.

[LMP]

www.avigex.ca/xport/readingcodes.jpg
My guess you have a code 21 or 22
www.avigex.ca/xport/dtc21.jpg
www.avigex.ca/xport/dtc22.jpg
IN such case TPS needs replacement