e28 M5 acceleration issues...

["James Nelson" <xi@xxxxxxxxxxxxx>]

Hi! My 1988 M5 exhibits fairly odd acceleration behavior---it can best be
described as a hesitation, and occurs mostly (always?) between 1% and 99%
throttle. It's almost as if the car can't make up its mind if it wants to go or
not. Once I put the pedal down completely, however, there isn't much hesitation,
if any.

I bought the car in April, and previous to that it was in storage. It underwent
a thorough check-up (including hoses/belts/cat/etc. replacement) at the local
BMW specialist, it passes smog, and otherwise drives fine. Swapping between the
JimC and BMW chips does not seem to make any difference in this arena. I've
heard that vane-type airflow meters can cause a similar behavior, is this true?
Or is there a way I can determine if my AFM is actually on its way out? Is this
a common problem on e28 M5's?

One other data point---it does not seem to accelerate as fast as I would have
thought. Our '89 750 keeps-up quite nicely with it, with such close HP numbers
(299 & 294) it would seem the e28 would win by a significant margin (given the
weight/transmission). The e32 can't quite corner the same, though. :-)

TIA,

James Nelson...
1989 750iL
1988 M5
1975 2002

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