E30 Zone

For starters, I have a total Frankenstein 320i/325e cabrio. I had a valve drop into the 6th cylnder of the 320i engine while on a road trip to south France. The donar car for the new engine wound up being a 325e, not a 325i. Did an engine swap anyways using the all the 320i wiring and a bunch of the 320i components (intake etc.), and surpisingly it has worked fantastic.

Until now. I have a strange thing that happens when starting on a cold day. The car always starts on the first turn, no problems. However, sometimes the idle will jump from 1000-2000 RPM for up to 30-40 seconds, then it is fine. I can't figure out what exactly is causing it. It even contnues if I try to put it in gear right away. Almost like it's driving itself. It doesn't ever occur again afterwards, but it the car is left for a number of hours it happens again at startup. It doesn't seem like a problem, but when starting on the street everyone thinks I'm a jerk or want to race.

Hope someone out there can help!

Griz

Odd that this is only on cold start up, is it absolutely fine once warm? at idle and across the rev range?

Very strange indeed. It will do this up to a minute or do, then it's fine. I'm wondering if it's trying to cope with a possible timing problem, but then it would happen every time....