Re: idle revisited

["David Teitelbaum" <jtrealty@xxxx>]

When the motor is cold the O2 sensor is not being used so you cannot
say it is bad because the motor hunts badly when cold. I still think
you need to go over the advance system for something hooked up wrong,
a defective part, or a vacuum leak. In addition I would check the
thermister circuit to the idle ECU. This is the sensor that tells the
ECU to run the motor at a higher idle when cold. It is uncommon (but
not impossible) for the idle ECU to be defective. Since you say you
have another Delorean to swap parts with then just switch the ECU's
and you will know if the trouble moves to the other car you have a
problem with the ECU. On the Deloreans that I have worked on vacuum
leaks are the #1 cause of idle problems. Don't forget that you can
have vacuum leaks from the seals on the injectors. They get hard and
stop sealing when they get old. They can get so hard that the
injectors are actually loose, the only thing keeping them from falling
out are the clips. An "O" ring can be out of place between the
cylinder head and the intake manifold. The "O" ring for the air tube
to the idle motor can be missing or cut. The point is there are a lot
of places that you can be leaking vacuum and the effect is cumulative,
ie, they all add up so it can be many tiny leaks making it impossible
for the idle motor to control air. If you have never had the top of
the motor off maybe it is time to do it, it is over 20 years since
those seals where put in origionally. Even if it was taken apart,
maybe there is a stripped bolt, or an "O" ring missing or out of
place. I am always amazed by what I find on some cars, from
missing/lost harware, to parts put together wrong etc.
David Teitelbaum
vin 10757


--- In dmcnews@xxxxxxxxxxxxxxx, Louie Golden <louie@xxxx> wrote:
> Hey group,
> 
> I've done some more fiddling around with my car's idle... trying to
figure out what the deal is. Initially I thought the cable was somehow
not getting enough tension to return the throttle arm to the
microswitch, but it looks like that is no longer the issue. The
throttle can return the arm to close the microswitch, but the
microswitch doesn't make the car idle down every time like it should.
I've lubricated the ever living mess out of every visable part of the
throttle linkage from front to back on the car for reference. When the
car is cold, it idles perfectly (well, as perfectly as a PRV CAN
idle...), but as the car warms up, something suddenly happens and the