I'm having this strange problem as of late with my 1989 740... It seems as if it won't idle correctly.,... If it tries to idle at the reccomended 850 RPM, it idles rough, and has barely any vacuum... It will then revert to idling at 1000-1500 RPM.... When driving, moderate acceleration is alright, but at WOT it really suffers from a bad hesitation... but if i don't go to the little "click" at WOT, it's nearly fine (although, still not as good as it was or should be)... Ever since I've had the car I've gotten a code 2-3-2 (idle rich/lean)... and every once in a while it backfires when i depress the accelerator... Here's a minor service history..

Oxygen Sensor - last year
cap/rotor/wires - last week
injectors, new 24# replacements - last week
rebuilt MAF - two weeks ago
New Jetronic "571" ECU - Last year (when i got the car)
new in-tank fuel pump - in the springtime

the hesitation got a LOT worse a few weeks back, and the recent parts replaced made it a little better, but it's still not right.... (i was getting a code 2-2-1 but not any more) and it starts considerably faster since the new injectors...

I also have never got "good" fuel economy with it either (11-20 MPG)

before i had it, it had sat for probably about 3 years

Cliff Scott
89 740 16v