A/c idle up/ wont idle up - Toyota Nation Forum : Toyota Car and Truck Forums

banshee35 · 07-06-2005, 06:51 PM

Ive got an 89 4wd dlx. The a/c idle up circuit is crap. Ive got vacuum at the switch and if i bypass the switch by hooking the hoses together, it works. I replaced the switch with another one(it wasnt new) and it still wont idle up. I'm getting frustrated w/ this. Any ideas? thanx!

texas12 · 07-06-2005, 09:13 PM

With the hoses connected and engine running, apply 12v to the VSV and see if it revs up. If it does, the VSV is good but not getting the signal to rev up. That signal comes from the a/c amplifier. It has an adjustment knob on it. Cut-off should be set 600-700 rpm's and adjustment knob is CW if cut-off is too high and CCW if too low.

banshee35 · 07-07-2005, 07:23 PM

apparently ive got a toasted vsv. it didnt do anything when i applied 12v to it. the rpm adjuster under the das/behind glovebox only messed w/ rpm engagement at idle. Any reputable places i can get one from ? I got the one that is on it off ebay(junk!

). Thanx.

benny_bell · 07-08-2005, 05:16 PM

hey guys

i have an 87 4runner and have a similar prob. when the a/c is on and trying to idle, it often surges from about 500 rpm to 1000 rpm, just keeps on cycling with a click every time under the hood (sounds like a switch coming on and off).

any ideas of how to fix this?

banshee35 · 07-18-2005, 06:45 PM

I checked for voltage today- Im gettin 12v with the key on (engine not runnin) regardless of a/c button.Engine runnin' w/ac button off voltage drops slightly and goes back up to bout 14 w/ ac button on-blowin dang cold air- no increase in idle. Evidently my bastard switch is bad, but what about that voltage??

banshee35 · 07-19-2005, 06:45 PM

am i missing something?

texas12 · 07-19-2005, 08:49 PM

Haven't had a chance to check mine, but I think the TPS is tied in with it. If the TPS is not adjusted correctly, it will probably cause problems with the a/c kick-up. I might have a chance tomorrow to look at it.

banshee35 · 07-19-2005, 10:21 PM

thanx, im sorry for buggin everybody w/ this. Its been this way for too long and i'm ready to fix it. Tryin to find a new vac switch also. ill check my tps and make sure it set correctly tomorrow and go from there.

banshee35 · 07-21-2005, 07:13 PM

I checked my tps, it was well within range. I vsv is toast. gonna order a new one and see what happens.

subliminaltrips · 10-21-2005, 08:16 AM

did you ever figure it out because im having a simlar , well exact same issue. the valve opens and closes properly and the set screw is adjusted to allow air to pass but it will not idle up with the vsv in the vacuum circuit. tried every possible combination of hose configuration to no avail. could it be its just not letting enough air pass through?

banshee35 · 10-21-2005, 07:58 PM

Nah, i gave it up. I've determined it's in the a/c amplifier though, Cuase the problem is electrical. I tried a new vsv, but it still didn't work. I've got the proper vacuum from the rite places but not the rite signal. I hooked it to 12v battery and it worked, so I know it's in the circuit coming from the a/c amp to the switch. I do get some voltage to it, but it doesn't work. If you or anybody else has any suggestions, I'm all ears. Thanks asking, subliminal.

subliminaltrips · 10-21-2005, 09:03 PM

so did you try hooking it up to the battery and see if it idled up? like bypass the ac and run power directly to the vsv. if that works then you coud rig it to the compressor clutch wire as its 12v and it should work if the a/c is running.or just put your own switch if you dont want to splice. try that and see if it works. by the way where did ya get the vsv? how much? try that and let me know because if it works like that its gotta be something internal. i know on mine the switch does kick on and when you put it in line with the vsv and back to the set screw thingie it seems like its not getting enough suction. i was also thinking that if there was a vacuum leak somewhere in the system it could cause it to suck from the leak. i dunno but i really want to fix this problem cuz im in florida and i need my freekin a/c !!!!!

banshee35 · 10-22-2005, 12:24 PM

Yes, I hooked up directly to the battery and it(vsv) worked.I did think of it,but I don't really want to jerry rig it up to my compressor. I've got the proper vacumm going to and from the vsv, or else it wouldn't have worked when i bypassed the power supply and hooked it to the battery. My problem is definitely electrical-somewhere between the vsv and the ac amplifier.

texas12 · 10-22-2005, 12:58 PM

Hey Banshee,
Checked my booked and I do I a wiring diagram for the a/c system. You are mostly likely correct that it is the a/c amp. The VSV gets its 12v from pins 4 & 5 on the a/c amp. If you always have 12v to the VSV regardless of the a/c switch, the amp is probably bad. I can scan the diagram and send it to you if you are interested.
Sublimin,
Unhook your VSV and check for 12v with a/c switch on and no voltage with it off. If so, I just bought a VSV from the dealer not long ago for $32.

banshee35 · 10-22-2005, 03:21 PM

Thanks texas12, i would appreciate that very much. I was quoted from 1st toyotaparts.com for a vsv for around 17 bux though. I just ended up buying a 2nd hand one off ebay for bout 10 bux. I didn't want to fry a brand new one so thats they route I went. Thanks again.