[Author Prev][Author Next][Thread Prev][Thread Next][Author Index][Thread Index]
Re: Fuel Injection Control Unit Diagnostics
At 01:56 PM 2/26/98 -0500, you wrote:
>I have been tracing down a high idle in my 88 90Q. From pulling out the
>codes, I got 4431 (ISV) and 2123 (Full throttle switch). However a separate
>test of the ISV reveals that it works. The switch on the other hand, seems
>to be stuck in the open position (I checked the switch and it works). All I
>have left to check is a possible faulty FI control unit. Has somebody
>performed a test of this unit before? Any recommendations and an estimate
>of how big the hole in my wallet will be if I have to replace it? TIA,
A defective full throttle/idle switch can definitely cause idle problems.
I can't tell from your note if it works or not (you said "it seems to be
stuck in the open position" and then "I checked the switch and it works").
Idle/full throttle switch on a 90q is part nbr#026-133-093-D, about US$90
BTW, 'working' on an ISV can be a relative term....it can be sticky
intermittently. It's worth a good cleaning even though it tests out good.
The other good candidate is a vacuum leak in one of the two hoses leading
to the ISV. I've got part #'s for those also if you need
Steve Manning: firstname.lastname@example.org
...Physical home: Metro D.C. area, USA
.....Virtual home: http://www.stationwagon.com