I just got my car back from the shop, which put in a used ecu. The overrich condition is gone and it is running much better. However when it is cold sometimes it bogs down when I try to accelerate. I checked last night and the shop had forgotten to reconnect the cold start injector. I thought I had it. However it did it again this evening. Where do I start? I checked the resistance of the temperature sensor two weeks ago with no problems found.

Clean the throttle body..and fix your vacuum leak..
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Max..1989 244 DL 5 Spd., Bilstein HD, Turbo Swaybars, Poly Bushings all round, Turbo Wheels, Black leather interior, Electric mirrors, LED dash and gauge lights.

Well you could just warm it up for a bit before you try and merge onto the freeway.
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Drive it like you hate it

I had an '85 240 that did the same thing. I replaced the AMM and that helped it a lot. On cold winter days the car was always slow to accelerate. Mine didn't really show the usual signs of a bad AMM (like stalling or no start), so you might want to check the connector on the AMM to make sure some of the pins aren't getting pushed back into the wiring boot. Does your car foul plugs if you try and drive it from cold (like it's loading up)?

Cheers,
Dave

Sorry, I forgot in your initial post that you said the car wasn't running too rich anymore. One of my turbo 740 wagons fouled plugs from a bad AMM. Even so, my '85 240 that I replaced the AMM on didn't run rich, so that could still be something to check in your case.

Dave