Picked up an '88 244 last week, nice condition, but had a rough idle. Get past idle and drive it and it ran quite well.
Changed the plugs, it was slightly better, but still pretty rough at idle. Started poking around sites like Brickboard and others, found it might possibly be things like the AMM or dried up injector seals.
One message in a forum said if the AMM is faulty, the idle should smooth out if you unplugged it. I tried that and it was better. So, I went into my trunk and dug up the AMM from my dearly departed '89 744 and installed it, and the car idles almost perefectly now, BUT it idles quite a bit higher than normal. Without a tach in this car, I can only guess at how much - perhap 300 to 400RPM above normal.
I checked some of the online parts sellers for info on the difference between the original AMM, Bosch p/n 0 280 212 007, and the one out of my 89 744, Bosch p/n 0 280 212 016. I learned that the '88 has LH 2.2 while the '89 had LH 2.4. This is apparently the reason for the p/n difference.
Now, the question is, can I continue to use the '89 AMM on this car, without damaging something over time, and adjust the idle down a little to make it right? Or is there enough difference between the LH 2.2 & the LH 2.4 that would rule out continuing to use this one and spending the $$ on the correct replacement?
I have yet to order a Bentley book for this one, so I would also need info on adjusting the idle properly if I can keep the setup as it is...
Thanks...
Dennis Putnam Co NY