Saturday night, i'm driving down the interstate and the car cuts off for maybe a second, then cuts back. The fuel gauge pegs itself waaay past the Full mark. Ran fine the rest of the night.

Sunday, car ran fine all day

Moday morning, car wouldnt stay on long enough to hardly get out of driveway. Car would cut off, the fuel gauge would peg. No codes. Car would not restart untill I pulled the PCM fuse. Then it would start, and then die a few seconds later. Might have cut off 4 times in my driveway.

Moday afternoon, came home from work. Car starts and idled fine.

Tuesday, I decide to take wild guess and replace fuel pump relay. Dunno if it fixed it yet. Car starts and idles, but it did that yesterday too. Has anyone else had anything goofy like this happen? I hope its not some BS like a ground or something, that crap is hard to track down sometimes......

 

My camaro did something like that onec it did turn out to be a ground. I see you have had your heads off mabey check the grounds... they are all at the rt front head. Check to make sure the stud is tight too. that was my problem I check the wires but it was the stud that was loose. I with your mods I would guess you have a aftermarket fuel pump to. Just check the simple stuff first maybe even the fuel filter. but that wouldn't explain the guage jumping around.

Good luck with it

Sean

 

You obviously have an intermittent problem. These types are almost always wiring problems or a device contact problem. The very first things to check are the easiest. Check all the contacts for power and ground for good connections such as at the battery, at the battery junction block and also check the grounds to the body and the engine. There is a braided ground strap that goes from the frame rail near the air pump to the engine. Check and clean those also. Also there are 4 gounded pins on the PCM. Connector A (Red) pin# 2(blk/white wire) and pin# 18(tan/white wire) and connector D (Blue) pin # 1 (tan/white wire) and last connector C (clear color) pin # 32(black/white wire). Pin A-18 and D-1 are grounded to the engine near the ICM. Pins A-2 and C-32 are grounded near the knock sensor. by the starter.

If that doesn't help, disconnect and reseat as many connectors as you can find.