A while ago, I took apart the throttle body and IAC on my 1997 3.4L T-100 4wd as was suggested for high idle that dropped only when revving the engine. It's been frustrating trying to get the idle to idle instead of staying at 15K when coasting in neutral or at a stop. I cleaned the MAF, throttle body and IAC, put on a new gasket at the throttle body and a new rubber gasket where the IAC joins the throttle body. I started the truck cold and it took 5 min to come to idle (800rpm). However, once I take it for a drive, the idle sticks at 13-15K when coming to a stop. I rev it and it drops to 800. Still no idle relief. Prior to putting everything back together, I hooked up the IAC to a 12v battery and got the roller to open some and close when disconnecting power. How much is it supposed to open with power applied...in other words when do I know if it's time to replace it? or can anyone think of another reason for the high idle?
Try taking the motor off and rotating the IAC valve shaft with yer fingers. You shouldn't have to take the throttle body off to do this test. The electric motor is held on with 2 philips screws.
Sorry about the typo....I meant idle sticks at 1500+ rpm
How will I know if the TPS is bad?
I'm with ya. Seem like TPS is defective. IAC wouldn't behave like that after it's warmed up. Get a book and it'll tell you how to test it. You'll need test meter around $40 will do.
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'86 Toyota Cressida 2.8 - super cool station wagon '95 Toyota T100 3.4 - 1 ton mod stake/flat bed
I'll try to find a service book (library maybe?) or is there anybody out there with a book that is able to tell me the multimeter test specs for the leads on the TPS....?
I would still pull the electrical motor on the IAC and physically rotate that valve shaft while spraying some cleaner through the port. It's highly unlikely the electrical motor has gone bad...it's yer call...
I would still pull the electrical motor on the IAC and physically rotate that valve shaft while spraying some cleaner through the port. It's highly unlikely the electrical motor has gone bad...it's yer call...
Great info folks, thanks a lot for all the input.
Forgive me if this seems like a dumb question...
Throttle open- I take that to mean manually opening the throttle where the cable connects to the throttle body with the engine off?
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Discussion forum for the short-lived but extremely popular Toyota T-100 model.
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'86 Toyota Cressida 2.8 - super cool station wagon
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