<E28> 535i Hesitation yet again.. Advice?

["Ron J" <ron@xxxxxxxxxxxxxxx>]

Hello All.,

Well the saga awakens yet again.. On my way to university to study at the
library for an exam tommorrow, the car started to hesitate mildly at first
and then more violently until there was no power at all, unless you put your
foot all the way to the floor.  Then the tires would spin, and as soon as
the RPMs settled it would hesitate again, and drop to about 500 or so.  I
pulled off the road, and looked under the hood, and could find nothing the
matter.  The engine was idling really rough, and eventually stalled while I
was looking under the hood.  I kept tinkering and when I tried to start the
engine again, I had a dead battery.  Luckily I there was a guy across the
street with a van that gave me a boost.  I got the car started and limped it
over to a garage.  The owner seemed to know the cars very well, and started
to look under the hood.  he said it was a vacuum leak by the sounds of the
hesitation and seemed pretty sure about that.  Anyhow, we tested the battery
and I ended up getting a new one.

By this time, the car was cool, and it started ok, and idled ok, but as soon
as it got warm again, it started the rough idle.  We checked all the hoses
and didnt seem to find a vacuum leak.  He then pulled off the (brand new as
of January) ICV valve, and said it wasnt working properly.  He did a test by
looking on the inside of the valve while he had another tech turn the key
from off position to on, without starting the car.  The little gate on the
inside stayed open the whole time.  The valve buzzed but the gate never
closed.  It would budge just a little but stay in the same position.  Since
the valve was new, he said that it could be the computer, or one of the
sensors near the front of the engine by the coolant intake.  Apparently they
signal the valve to open/close.

As a side note, the hose running from the bellows to the valve cover (1"
diameter) with a smaller 1/4 line running off the bottom was cracked.  It
has electrical tape on it, and it wasnt leaking, based on what I could see,
and what the tech said.  I am going to replace it anyway.

He wanted to keep the car overnight and look at it tommorrow, but I said I
needed it for exams tommorrow at university, so he said to bring it in
afterwards.  He was going to check the signal to the ICV, and from the
sensors.  I said I would bring the car back.  I left, and about 5 minutes
away from the shop the car started the same behaviour again, and the exhaust
got so hot, the rear rubber hanger caught on fire again.. I guess it was all
that unspent feul in the tubes.  I put the hanger out, and now the car is
parked.  I cant get to my exams tommorrow, and I dont want to try driving it
to the shop again.  I guess it will have to be towed in.

Any suggestions as to what might be causing this?  New ICV, new FPR (2nd
one. purchased from the dealer this time)  New Cap and Rotor, new feul
filter, new plugs, valve adjustment, and no visible vacuum leaks.  Could the
ICV be causing this bad running condition?

Please help

Thanks
Ron J
85 535i

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