I'm going to his home on sunday to help him with his drama. He tells me the problem happens only when the engine is up to temp, at idle or when off-throttle decelerating.
It makes me think there maybe a drama with the oxygen sensor as
it happens only when hot, thinking, closed-loop operation only works at idle and light (or no) throttle and only when the donk is up to temp. Though the car runs fine on the highway which I thought would be closed-loop too, maybe not.
He ran a diagnostic test on the IAC valve and said it passed the test. He mentioned the test ran the engine up to particualr rpm for 3 seconds or so. That sort of counts out the IAC mostly I guess - maybe? Can still run a continuity test on the windings though.
I have a decade box(precision stepped resistance box) which I can use to simulate any resistance value, especially the water temp sensor to confuse the engine into thinking it is cold and more importantly force it out of closed-loop operation without causing a the engine light to come on.
I have a spare oxygen sensor from one of my Cressidas for testing. Hopefully the mounting flange is compatible.
Any other suggestions over the next day would be great. Can't believe the local Toyota dealer couldn't find the problem.
Fri, 02 December 2005 13:13
