1994 XL still idles funky

[monkeydude3]

1994 XL 4.0L OHV here... manual transmission. Once the idle kicks down from the intial 1500 rpm high idle cold idle... it goes from 750 rpm to 950 gradually as it gets hotter. Once it's hot, it idles fast. I'm not sure why it gradually in creases. new T stat, IAC.... I am thinking my TPS is to blame because it is somewhat related to how much I hit the gas. It idles slow until I hit the gas. the TPS is a little sticky on the bottom in that the resistance value doesn't max out when I release it, but i tried a new onea t autozone and it doesn't do that. It sounds excellent idling at 750 or so, nice rumble... but when it idles at 950 it sounds like someone is holding their foot on the gas but no one is... ::sigh:: getting rid of it this summer anyhoo. Any ideas??!?

George

 

[Rhett]

Your post kinda runs all together and confuses me but I think I can understand what you are saying.

Sounds like what my truck was doing when the throttle set screw and TPS were not calibrated correctly. How does your truck idle when the TPS is unplugged?
If I remember, should be 500 rpm. Adjust the set screw (located on the throttle body) to achieve this rpm. Then when the TPS is plugged in you oughta idle at 750 rpm or so.

Also you gotta make sure you really are not overheating. I can't tell what your temp gauge is doing from your post. A lot of PCM's will actually increase RPMs a little when the engine is overheating, in an attempt to move air and coolant to try to cool the engine.

 

[monkeydude3]

hmm.... not overheating as far as I can tell. I opologize for the long post. My mind gets going and I don't realize I'm blurring a lot together. The temp is usually in the middle of normal or a little bit lower. It's never actually overheated in the time we've had it. The last time I un plugged the TPS it raced to like 1500 rpm. It's just very confusing as the idle increases as it warms up. May be a temp sensor thing as well. Oh yeah I also have a radiator leak I discovered today... WOHOO!

George

 

[Rhett]

Did you get it figured out? The rpm's should not increase when you unplug the TPS...
something is wrong there.