NetNews Usenet Archive 1992 #27/NN_1992_27.iso/spool/rec/autos/tech/15522

Internet Message Format | 1992-11-17 | 1.6 KB

Path: sparky!uunet!hela.iti.org!usc!cs.utexas.edu!gateway
From: [e-mail]
Newsgroups: rec.autos.tech
Subject: Re: Stalling problem.
Date: 17 Nov 1992 09:31:49 -0600
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    "Does this TBI have a seperate injector for cold starts? Has anyone got
any ideas?"

No and yes.  There's a very good chance the symptoms you describe (stalling on
drive-away warm or cold) can be accounted for by an erratic throttle position
sensor, especially in an older car.  GM uses this ultra-cheesy TPS that seems
to be designed to wear itself out.  The maximum wear happens where the pot
wipers spend most of their time - at idle.  Over the rest of the range, you
still have enough resistance material to get a signal out of the thing, so no
driveability problems while under way.  This won't necessarily set an ECM fault
code either.  To test the TPS, disconnect it and hook up an ohmmeter between
the center pin and either end.  You should see some resistance in the low
thousands.  Then lightly tap the sensor housing and watch the meter (an analog
VOM works best here).  If the needle jumps erratically in response to the
tapping, replace the TPS, even if it's not completely shorted or open.  That
fixed the problem in my wife's 84 Skyhawk with the 1.8 TBI.  The TPS there is a
total pain in the butt - you have to remove the EGR valve to reach the bolts
that hold in on, and it took a crow's foot wrench to get the flippin' EGR off.
Good luck.

            - Michel

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