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Re: 325e Fuel Problems

> My 88 325e is extremely sick.  The initial problem was when the car is first driven, after 2 to 3 blocks the 
> car would die... no idle... I would need to give it massive throttle to keep it idling.  The next thing that 
> happens (as I am giving it too much throttle) is black smoke would pour out of the exhaust pipe, as seen 
> through my rear view mirror.
> 
> What I have done to the car as of late:
> 
> 	1) Replace both fuel pumps. (The new external pump buzzes more than the old one)
> 
> After no luck troubleshooting I took the car to a Local BMW specialist, this is what he found/repaired:
> 
> 	1) Replaced the airflow meter
> 	2) Replaced the Sparkplugs
> 	3) Replaced the Timing belt and adjusted valves
> 	4) Checked and adjusted idle and CO
> 	5) Replaced Water pump
> 	6) Fan Clutch
> 
> Now the car doesnt die anymore but still has a constant random "miss" when idling.  In addition, the car has 
> reduced power when accelerating in the high rpm range (4000-5000).  The mechanic also said that at high rpm the 
> CO and HO levels were too high.  His next suggestion was to inspect the ECU and throttle switches...This trial 
> and error thing is getting old.

First of all, is this car an '85 or '88?  (conflicting info here)
Has the fuel pressure been checked?  Fuel pressure regulators do go
bad, especially after 10 years and 150K or so miles.  Was the coolant
temperature sensor checked, and the wiring?

If the car is an '88, there might be a problem with a bad connection
in the Motronic harness.  '88 or so onward cars have a Motronic harness
with a seperate sub-harness for the injectors and coolant temp sensor.
There is a round plug underneath the intake manifold that connects the
sub-harness to the main harness.  What will sometimes happen is that coolant
will leak from the throttle body or the heater, run into the harness, and
end up at the plug connection, causing it to corrode.  After a while, the 
connectors become dirty, and no longer properly pass current.  This can
lead to uneven running due to either or both faulty injector operation and
the ECU being fooled by a bad coolant temp reading.

If this is the case, the individual plug connectors are replaceable.
Several dollars from the dealer.

Air flow meters also go bad, but I'll assume a new one was installed.
ECUs don't typically fail in this manner, but it is also possible.

Hope this helps,
Ben