Fast Idle Thermo Valve 101
Vehicle: 1995, F22B1, AT
My Honda has an Idle Problem: i posted this a few days ago but did not get any response. i know it looks lengthy and that techs do not like to read, or are too bored with this subject and prefer to read a highly technical horsepower increase post. but i was just trying to relate all the facts and concerns, out of respect for the board. so if it is too long then just tell me everything i need to know about setting the FITV inner plastic valve -- a 101 on the FITV. the FITV is just lying on the bench and i need to get it back on the car asap. below are the detailed facts and concerns if anyone prefers to read it:
After the engine reached operating temp and was stabilized at 550-750 rpm, i revved it to 1,500 and 2.000 rpm. i was trying to get some coolant i added circulated in the system. when i left off the throttle, the idle did not go back to where it was, it went from 1,000-1,300 rpm. i read about adjusting the Fast Idle Thermal Valve's inner plastic valve to eliminate any air leaks occurring at op temp. i took the FITV off the TB. personally i would rather have a 1,000 - 1,200 rpms maximum cold start idle.
but my concerns are this:
1. if i tighten the valve all the way in can that cause any other problems with the related systems or parts? ... perhaps change the normal operating idle range of 550-750 rpm? ... or cause the ECU to think there is a problem and set off a fault code?
2. what rpm will it idle at when cold then?
the F22B1 VTEC's are programmed to run a fast idle of 1,000 to 2,000 rpm on a cold start ??? the Honda Service Manual (HSM ) troubleshooting chart lists the cold start idle problem this way: "When Cold Fast Idle Out Of Spec (1,000-2,000 rpm). the 1,000 to 2,000 rpm is the correct rpm range. my car starts up at 2,000 always, and then gradually drops down. the HSM says "The FITV is factory adjusted and should not be disassembled." a local Honda parts guy told me he would not tamper with it, telling me i could screw something up. is that true? some people are saying to turn it all the way in (easy to do) and get rid of the fast idle entirely. others are saying to turn it in until it is not loose, thats not so easy to do, because no one on this Honda Tech website is providing any description of just how far or in or out you need to set it. more details are needed, for example, someone could say the following:
"Turn the white plastic valve all the way in, and then back it out one full turn, and that will be the correct factory setting. But if you want it to idle lower and still come within the engineering spec, then back it out 1/2 turn."
when i took my FITV off, i was able to turn the valve about a full half turn until it stopped, using normal pressure, not trying to get it real tight, just a normal stopping kind of snug. as i said above, i was at 2k rpm, so where will it be now? is it better to at least let some air in? if that plastic valve is turned in all the way, won't that put lots of pressure on the plastic valve end caused by the metal spring at the other end always being under tension?