Re: Error code 2121

[Andrew Duane USG <duane@hunch.zk3.dec.com>]

Hairy green toads from Mars made MMGreger@aol.com say:

> I've been having problems with my 91 100 lately.   It wants to stall after 
> being driven 1 to 1 1/2 miles after a cold start.   At that point it drops 
> back to idle for 30 secs or so, at which point it begins to run normally 
> again and will not restall until after another cold start.   I pulled the 
> fault codes and got a 2121 which translates into "Idle Switch".  My questions 
> are;   1. has anyone else had a similar problem, 2. can the idle switch be 
> responsible, and 3.  where is the idle switch located and how do I identify 
> it?   I have a parts car which was operating normally before an accident, so 
> I can easily change out parts.  Thanks.

It could be the idle switch, or it could just be the accelerator
pedal cable is misadjusted so the idel switch doesn't get pushed.

Follow the cable all the way to the throttle body, and check the
two stops. Make sure it rests against the idle stop, then have
someone put the pedal to the metal and make sure it hits the
wide open stop.  I guess there are also switches at both places,
but this picture doesn't show them.

To check (did this on my old 100Q lots), just unplug them and test
for continuity or not with a multimeter.

-- 

Andrew L. Duane (JOT-7)			duane@zk3.dec.com
Compaq Computer Corporation		(603)-884-1294
110 Spit Brook Road
M/S ZKO3-3/U14
Nashua, NH    03062-2698

Only my cat shares my opinions, and she's too psychotic to express it