fiddle_jake

Hey everyone. Thanks for being so generous with your knowledge. I have a 1990 pickup that runs great except for when it idles after warming up. It acts like the timing is way off. I did the 22re tps tests per http://www.4crawler.com/4x4/CheapTricks/TPS/index.shtml and everything is good except IDL - E2 is always infinite. Could this be why my idle is so bad? Will this make me fail smog? Thanks so much!

MID SIZED BOSS

where do you live bud?

peckinpah

Are you sure the TPS is adjusted correctly? The amount it needs to be moved to get within spec is like about the width of a hair. My guess is that you need to loosen it and do some very fine adjustments to get the correct readings. And if that doesn't work, the unit may be faulty.

Does the idle change when you short the T and E1 terminals to set the timing? If not, that's a sign of a bad (or possibly mis-adjusted) TPS.

In CA, I failed smog a few years back because I had a bad TPS, so I know that it does matter here. Plus, you don't want to be driving around with something broken like that, which could lead to other stuff breaking. That's my philosophy anyway, FWIW.

BigSwole

jake, my opinion is to work it and work it, peckinpah is right, its a SMALL change to be correct vs being wrong.

and yes it will hinder your idle.

alligator clips + allen head screws will be your friend here. made it 10,000X easier for me. still a PITA but just a lil less.

razed

if idl/e2 is always infinite, the switch might need adjusted or could be bad.

4Crawler has adjustment instructions on his page too.
Did you follow them to try and fix the problem?
If you did, and couldn't fix it, the obvious solution is to replace the TPS.

fiddle_jake

Thanks guys!
@MSBoss: Sorry, I should have said I fall under California's smog rules.
@pechinpah: Good to know that it's so sensitive.
@BigSwole: Good advise. I'll take it to heart.
@razed: It actually didn't occur to me that it might be out of adjustment. I have 230k miles on the truck and the TPS has never been touched.

I'll try all of the advice. I also need to buy a new timing light. A friend gave me a really fancy one that worked great for 10 years but a while ago it started smoking. Since then, I've gotten lazy and just change plugs and oil. I own 3 toyotas and rarely have a problem with them.

Thanks again. God bless.