RE:<e28> '87 535iS -- Intermittent Drivability Problem

["Georg Taht" <tfam@xxxxxxxxxxx>]

As an owner a 535is with BB Tri-Flo Exhaust (love the sound even if it is a
little loud in the 2500rpm range) and Dinan chip(much improved low end, with
great top end right to 6600rpm cutoff).  I can confirm your mileage.  Best I
have seen is 27.5 mpg with cruise set to 70mph.

Here are my thoughts on stalling:  A friend of mine has a 87 L6 (635CSi)
with a very similar problem.  It started out with intermittent loss of
power, but idle was fine.  Then it would run fine for a few days and start
all over.  Replaced all the components you listed with no help.  The final
fix end up being replacing the DME unit above the glove compartment.  It
turns out that the windshield was leaking and water was getting on the DME
unit.  It was shorting it out.  Windshield fixed and $700 later for a DME
unit car has been running flawlessly for the last 5 months.

A long shot may be to look at the air duct from the flow meter to the
throttle body.  If it has a crack and leaks air it may cause what you are
experiencing.  However my experience with leaks in the air duct were bad
idle.

Hope this help.

Georg
87 535is 5-speed

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