The original unit failed about a year ago, kept getting Code 21 if it idled for more than 10 seconds. I check it with a multimeter and tried adjustments to no avail. I purchased a new one in September fo $25 and all was solved. Well about a month ago, same thing, Code 21 again as above. I tried adjustments again to no avail.

1. Is this a bad TPS, or could some underlying problem caused the new one (and the original one) to fail with only a few months service? I still have the receipt from Autozone with a one year warranty.

2. What does the Code 21 mean? Can I ignore it and keep going with no problems? I have not notice any change in operation this time or the last other than that irritating CES light.

Thanks

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1986 Black/Gold LG4 Z28
Original Owner, 200,000+ near trouble free miles.
Mostly Stock.

1995 Dark Red Metallic Corvette Coupe Original Owner

 

Anyone?

 

Joey- Have you pushed the TPS plunger while the engine is idling? When I did that on my 83Z, the engine would almost die. Have you checked the TPS for proper ohms with your
meter. Sorry I don't have my Helm manual here, but I think you put the black wire from
your meter on the center TPS terminal and
the red one one the top and then the bottom. Push
the plunger under the accelerator lever down
with a feeler gauge and note any change in
ohms. If you have to replace the TPS make
sure you have the spring under it and hold the TPS down with a stiff feeler gauge as you put the airhorn on. Also make sure the green plunger under the accelerator arm does
not fall out of place.

Nordbert