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Where can I get info on adjusting my TPS on a 90 model FI motor, idles very high when first cranked (3000 rpm's or more) for a good while then finally calms down. I DID A SEARCH and found that it could be adjusted, but dont read anything about it in my haynes. Any help would be appreciated

Mark

 

[Guest]

mark
I really do not think its the TPS.Assuming from what you posted your idle stays high when the engine coolant temp is low and then as the temp rises your idle drops down to normal.Right?
Ok then if this is the case the cold start valve may be out of adjustment.looking at the throttle body from the front you will see a small round cover with three screws spaced evenly around it pull these,the gasket and the cover and behind this is a plunger turning it out will lower the cold start RPM. see this thing is equal to a choke .There is a coolant line going into the rear of this housing, when the temp is cold this plunger is in a retracted position allowing more air to pass, as your temp rises this thing pushes out thus closing off this passage bring the idle RPM back to normal.
BE FOR WARNED!!!those little screws are nortorious for rusting and WILL BRAKE OR STRIP.so unless this is a major headache or a pet peave just live with it I belive that the manual states that warmup RPM is like 2200-2500 anyway.so if you are at 3000 your not to far off spec.
Also dont mess with the TPS unless you show a fault "ie ENGINE light" is on and the code comes back stating that it is this thing.These can be a real pain to dial in and even more so on a high milage unit.You need an ohm meter for this and i do not have the specs handy right now.
Hope this helps
Bill

 

[254]

Thanks Bill, I will give that a try, I think I performed this fix on a 90 Tracker a few years ago, (my memory doesnt go back that far) I will give it a try

Mark