S54 e36 inconsistent power and no A/C

[e36seanp]

Hi guys,

Recently did the swap into an e36, I had another thread about a cooling temp sensor issue I was having. Was able to get that fixed. Unfortunately I have just a few problems left in completing and having a 100% functioning swap.

The current issue I’m having is an inconsistency of power. For example, in 2nd gear around 3500 I’ll pin it and at about 4000rpm the powerband hits harder than other times. It’s really strange. Sometimes my car is damn fast and sometimes it’s fast.

I also notice that if I’m in a gear and take it past 4500 and then let it drop to 3500 and then if I pin it, it usually has a harder hit in the powerband around 4K. Was thinking possibly a vacuum issue but everything is plugged.


There are a few issues that I think could be making it act like this.
1. Pending CEL for SAP pump code p0418 (open circuit in relay) (do I need a sim for this? Even though I removed the code?) pump hardware is still in the engine bay
I recently fixed (I think) the issue by plugging a wire to pin3 on the ecu and connecting it to the sap relay signal ground wire near the fusebox. Maybe the pending code is keeping it in somewhat of a limp mode. I also noticed when I reset my battery (have been doing it a lot) The car seems to be fast for the few few miles and then goes back to being inconsistent.

I’ve been trying a few things over these last few months but nothing seems to fix it. Maybe the pending code is waiting for enough heat cycles to turn off or maybe I just need to drive a few hundred miles to let the computer learn itself. I’m currently in a bind.

The last issue is having no A/C, I have Andrew CAN bus and connected the e46 m3 pcm module to the stock auxfan assembly in my car. I was under the impression that this would fix the A/C. It’s not kicking on, fuses are all good. No idle bump either. Any ideas?

Any help would be greatly appreciated. Thanks guys

[e36seanp]

It also had me thinking it might not be a software problem and more so of a hardware issue. Or possibly both
Things I could think of:
- dirty injectors
- vacuum leak
- fuel lines not big enough?
I do have the correct fuel pump and fuel pressure regulator