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the photo of the iac valve in the 1992 fsm manual is different from the one mounted on my trottole body, are the installation rules the same?
also my tps sensor is different from the 1992 manual
Sounds like your throttle body may not be original to the car? Can you post a photo of your TB area on top of the motor? There should be a part number stamped into the side of it also....
yes it is night here now tomorrow I will do it thanks, I have another 1992 FSM manual but with the white cover and the photo of the trottle body is different and both the iac valve and the TPS sensor are the same and it is possible that the 1992 has two trottles leotard?
In the first manual above, you're looking at the section of the manual that applies to ZR1 Corvette engines. The top of the page which says "VIN J" means it has the LT5 motor, which is different than the second manual section that you're looking at. The pages marked "VIN P" apply to the LT1 engine that you actually have in your car. So use the installation rules for that IAC valve in the " VIN P" section.
I fitted the new iac valve as the FSM manual says, adjusting the tip to the size of 28 millimetres, but in parking the engine runs at 1500 rpm, perhaps because the new iac valve has a smaller tip and needs to be lengthened to a few millimeters more yes it can reset or stretch more after it has driven a few kilometers because the manual says it can break
I replaced the iac valve I followed the procedure in the FSm manual, 1) mounted the valve 2) attached the wiring 3) accelerated slowly and turned on the engine for 5 seconds then waited 10 seconds and turned on the engine and traveled 20 km but the engine remains at 1200 rpm I tried three times but always the same I tried to lengthen the valve pin a few millimeters and the engine rpm drops a little but always at 1000/1100 rpm can I try to remove the valve and lengthen it again? Is there a procedure for resetting the valve after it has traveled a few kilometres? Do I have to disconnect the battery before fitting the valve?
Just a thought.... i had wierd idle fluccuations too. Tried 2 different IACs with no change. One day my 88 L98 started belching smoke and running terrribly. Long story short my coolant temperature sensor went bad. Related or not, that settled most of my idle issues too.
It can send wrong signals to the ECU. What the ECU does w it is something that other folks would have to verify. I was saying it helped my situation.
Im also not a fan of throwing parts at a problem. But the sensor wasnt a lot of money... plus for the black smoke and such that i was experoencing, it is the typical fix.
From: Liliha Bakery stuffing my face with coco puffs!
I tried to poke around my 1990 FSM but I couldn't find anything that say the IAC wire voltage "should vary on a running engine." With key on engine off, it's my understanding that the "stepper" motor will be parked at a predetermined value that is written in the program (PROM) which is ~145-160. This in turn means the pintle is retracted (almost fully) to allow more air to bypass the throttle blades in preparation to startup. Upon startup, the 145-160 should decrease as the engine warms up and at operating temperatures reach 5-50. If it sinks to 0, then it's possible there maybe a vacuum leak or read below... Of course this would be a lot easier to see with a scanner...
the size of the iac valve pencil is the same as the one I had previously but the engine always runs at 1500 2000 rpm, I followed the procedure in the manual, I wanted to understand why the valve remains open even when the temperature rises to 80 90 degrees Celsius and I thought that the problem was that there weren't enough volts to make it work properly. with the key in the on position with the engine stopped I have values of 0.29 volts 0.30. the wiring is not interrupted I measured the resistance from the valve pins to the ECM pins and it is ok, perhaps the ECM does not close the valve, because it always remains at the length of 28mm as set by the FSM manual, I have to measure with the engine running but the manual does not say how many volts the iac valve works at.
iac valve technical question
