How to adjust throttle position sensor on 86 caprice

SOURCE: Car idles high and does not recognize the TPS.

my 1995 camaro just started to idle to high what could it be

SOURCE: my 1992 chevrolet caprice idles up and down and if

COMPUTER CABLE HARNESS IS MAKING CONTACT WITH EXHAUST MANIFOLD, HEATING AND BREAKING AISLANTS. IF NOT, SOLICITE YOUR MECHANIC TO RE INSTALL THE MODULE THAT IS INSIDE THE DISTRIBUITOR AFTER CLEAN THE REAR CONTACT VERY WELL, CAPTION COIL MAY BE DEFECTIVE TOO. CHECK KNOCK SENSOR BECAUSE A DEFECTIVE ONE WILL CAUSE THIS PROBLEM TOO. IT'S A COMMON FAIL IN THIS MODEL OF CAR

SOURCE: replaced the throttle position sensor and now have

You must adjust the TPS to 1.5 volts with a volt meter

Dave C

• 1050 Answers
• Posted on Jun 21, 2010

SOURCE: I have a well kept 91' Chevy Caprice V8 5.0L TBI.

It's very common for these engines to develop a vacuum leak around the base of the throttle body. You can check for this with a stethoscope or a can of aerosol carb cleaner. Also, IAC valves are a common problem, but easy to clean before you replace it. Remove it and use the carb cleaner and a brush to remove the build up, also the crud inside the IAC orifice. Next clean the throttle butterfly valve and throttle bore thoroughly with carb cleaner. If this doesn't help, remove the egr valve and try and poor a little paint thinner through it when you're holding it upside down, it may weep a little through the pintle but it should not obviously allow the paint thinner to flow through. If all of this fails to help, you'll have to get your hands on a scan tool and read IAC counts at idle to see what the computer is trying to do. If the counts are high...above 50, the computer is trying harder to open the IAC to keep the engine running because of some kind of problem, usually mechanical. If the counts are very low...below 5, the the computer may be trying to counter a vacuum leak that is providing most of the idle air, which is unstable and can cause the stall.

Hope this helps.

Testimonial: "I added more comments for the first poster but maybe you can put your second though also. I checked the EGR and took it off for a closer inspection, also took out the IAC cleaned it with rag with some solution and brushed it. My question is, how far out should the needle be or how can I tell when the IAC is warn out. thanks ."

SOURCE: 1998 Astro code P0102 low

Try cleaning the TPS and IAC( idle air control) valve .also clean the throttle body with throttle cleaner.Then see, if that is helping.If not then MAF needs to be replaced, as the error code is triggering towards the MAF.--------
The IAC valve is screwed in to the side of the throttle housing (where the gas pedal hooks up to the engine).You'll need to remove the interior engine cover(dog house).Torx screws for the covers, 2 bolts on floor. and bolts against the fire wall (You can use a long extension with a swivel socket at the end).----------- This will help.Thanks.Helpmech.