1984 318i m50b25tu swap poor acceleration limp mode?

[shipwr3k]

I just swapped my m10 with an m50b25tu. It idles around 1000 rpms and does fine under about 3k rpm. However when I go over 3k or mash the throttle my car goes nowhere. I cleaned the icv ohm'd out most of the sensors, checked for vacuum leaks cleaned out and replaced the maf 3 times(used). I checked codes and it only brought up a maf code. If theres a big enough vacuum leak could it throw a maf code? Has anyone ever experienced this or have ideas on what it could be? Or where there might be an obvious vacuum leak I could've missed?

Is it fuel pressure related?

I've also heard not wiring the vss right could put it into a limp mode. On the 84 the vss wiring is in a different spot. I had it connected pin 14 on x20 to the green wire under the dash on c104.

Any help would be greatly appreciated. Its my only car and I need to get it back on the road. My girlfriends getting tired of me driving her 325e.;D

[THEhomelessONE]

Weird that it idles so high, I've got the same motor and idle at 600~rpm. Ever take the intake manifold or injectors out? Wouldn't hurt to have the fuel pressure checked, only problem I had was a bad fuel relay. GL

[N-Gen]

It might not be a case to be concerned about the idle rpm especially if the ECU chip was changed. I've swapped mine with a ~800rpm idling one and I've seen 1000rpm+ ones being marketed as aggressive chips.

I can't give any input about this issue though since I've not swapped mine yet and have no clue what could happen.

[justin_l_]

The idle is bumped up for tunes with light weight flywheel and or cams usually.