Car dies After Rev'ing it up

[e30f3ver]

Did a S52 OBD1 swap into my 91 318is. Car runs and idles fine. I can rev it up but soon as I let off it dies. If I rev it up and slowly let the revs go down car stays on. I have searched I keep seeing things about vacuum leaks but I cant find any leaks. Anyone have any suggestions? The car is running open headers but no exhaust setup yet so no 02 connected currently. Thanks

-Sel

[cormier]

Vacuum leak. Check your icv too.

[AnimalE30]

I had this issue intermittently. I believe it was because of the lightweight flywheel and the DME not being used to it. Problem got better overtime, and was only cured when I grounded the dme with the mounting bracket. Some people will say you need to ground the dme itself, and some will say it isn't needed.

[e30austin]

Get some exhaust on it. The 02 could be getting feedback from the fresh air. If that doesn't do it, and you're sure you have no vacuum leaks, look into knock sensors on the block.