[Shotimes] IAC voltage questions

[Kevin & Cheryl Airth]

> Fall's here and so is my annual battle with bouncing, surging, erratic
idle.
> Since the problem rears it's ugly head as temps drop one would think it's
a
> temp sensor. I've checked all out per Probst manual directions and all are
> OK. I get no error codes [unless it stalls and I get that fuel pump error
> code, which I ignore]. The one device that doesn't check out properly is
the
> IAC [or IAB or ISC]. The valve itself checks out fine but the signal from
the
> EEC-IV module doesn't read as the Probst manual says it should. The manual
> states backprobing the wire from the module with engine running, the
voltage
> should vary from 3-11.5 DCV as you slowly increase/decrease engine RPM. I
get
> 10 volts at idle and it decreases to 8.5 as I increase RPM. This has been
> done with engine at operating temp. If I don't get those #'s the manual
says
> the EEC-IV module or wiring may be faulty. Has anyone anything related to
> this test or my #'s or anything that may clear up my problem. It is a
clean,
> new IAC valve and, as I said, all other sensors check out properly. I'm
> leaning toward a funky computer, thoughts???
 Thanks!!
 Bob 93 MTX

Bob:
 Have you check your plug wells? My idle smoothed totally out when I cleaned
the oil out. I had done the silicone trick but less than 10K miles later I
put new seals in with silicone again. Just a thought!
.
.