Symptom: Recently my '91 740 (70K) started to idle strangely, very low and very high. About one week later it went to a no-start situation (OK, it started but bucked like a bronco and died within seconds).

Solution: The throttle body was completely clogged with gunk and must be REMOVED and cleaned. REMOVE and clean the IAC valve (directly under the throttle body) at the same time.

Reason: The crank case gases are recycled back to the throttle body where they build up over time clogging small passages, and causing the throttle plate to stick shut (the later is a no-start situation).

Conclusion: This is a rather simple job and should be done at the first sign of strange idle. It's surprising how fast this goes from strange to dead, in my case about 10 days total!

I hope this helps someone...

Ron