an1176

Holly crap I'm really confused now. With a crapped out ac system (I don't know what) when I push the ac button my idle should rise right? Mine is not.
I started on the ac today replaced everything but after 3 expansion valves none of them were right. I ended up ordering another evaporater in hopes that one of the expansion valves will fit. I'll be cracking at it again tomorrow. I'm so frustrated with this ac system I could set fire to everything I did today. None of the expansion valves fit the high side line but one and that one wouldn't fit the evaporater. I hope the parts I get tomorrow will work.

ozzir70

I am also a little confused now but I'll get it figured out. Fyi, I got my evaporator core from Rock Auto, a Denso that is OE and fit perfect, and my expansion valve came from NAPA, which also was a spot on match

an1176

What year is yours? I got my whole kit from rockauto. Outside of the plug on the compressor not matching and the issue with the evaporator and expansion valve everything else was fine. I'm not sure which evaporater I bought. If tomorrow's don't work I'm gonna order the denso and see what happens. My evaporater looked horrible, very nasty.

an1176

I sprayed my old expansion valve with some carb cleaner and blew it out with air compressor. Wonder if it is reusable. You can blow air freely through it.

ozzir70

Mine is an 87

grumpin

Sorry, I wish the FSM had a detailed description of operation. When you said you adjusted the black RPM knob, I forgot that one was there. Mine has not been a problem so I've never touched it. I'm certain that there isn't two places to adjust the idle up. And I know you adjust the RPM at the Plenum. I would put the black knob in the middle and go from there. I hope it goes well for you.

ozzir70

But my truck never had A/C, I had an 86 I took the evap box and wiring out of.

an1176

Thanks to everyone for your advise and help. I'm hoping it'll all work out tomorrow. By the way I've screwed the idle knob in and out all the way with no change. I have not messed with the amplefier yet. Guess if I get everything running tomorrow and my idle still won't go up I'll mess with the amplifier.

scope103

Idle-up is almost trivial to diagnose. Get a 5/32" male-male vacuum fitting (or scavenge a ball-point pen) to connect the metered air line to the plenum line. Does the idle increase? Good. It sound like your valve isn't opening. Note that it is a piggy-back valve; the VSV puts vacuum on a diaphragm that opens a larger valve.

If the idle doesn't increase with the "jumper" method, check the plenum line for vacuum. I don't know anything about the 22re, but the 3VZE can get a lot of "crud" (that's the technical name) inside the plenum (mostly from the PCV). Over the years, it can actually cover the vacuum ports.

Don't confuse the idle-up with the control ON the A/C amplifier. Idle-up is only that; when the A/C switch closes, the engine idle increases. The control on the amplifier shuts off the compressor when the idle gets "too" low. (To keep the compressor from stalling the engine.) You want that control set so that the compressor turns, even at idle, when the A/C switch comes on. But if your idle is too low (bad idle-up?), having the compressor come on could stall the engine.

grumpin

"You need to try that question again."






That's what I was saying.

an1176

Well it's done. Finally found an expansion valve that would fit. Couldn't find the right evaporater. I cleaned my old one that was nasty and put it back on. Ac works but idle up still doesn't. I messed with amplifier and set to kick on the compressor at the lowest rpm but truck still won't idle up. I tried messing with ac idle screw and nothing. When I take the two vacuum lines loose from vsv and put them together it idles up on the vsv it does nothing. So I'm guessing problem is vsv.

scope103

When all else fails, Read The Fine Manual. http://web.archive.org/web/201102052...24vacuumsw.pdf (test procedure for VSV)

grumpin

Good! I had to replace my VSV.

an1176

Update; so with my idle up vsv still not working I went to a pick and pull place looking for VSVs. I didn't find any like mine but I found a mid 90s camery with a row of 4 VSVs all of them different then what I needed. I decided I'll try them can't hurt, 20 bucks for 4 VSVs. One of them actually worked even though it's a different vsv. Now the problem is after I turn the ac the truck idles up like it should but after about 5 minutes it stops and idle drops again. I'm at a loss... I did mess with the amplifier when changing everything. I set the amplifier to its lowest setting to kick in the compressor. Could this be the problem now?

ozzir70

I am adding A/C to my truck which never had air. i do not have a VSV. Does anyone know if i have to have a vsv to make the air work?

scope103

The VSV controls the A/C idle-up. Without it, when you come to a stop the compressor will stall the engine. You could sorta get around that by jacking up the idle, or turning off the A/C at idle, or remembering to keep your foot on the gas whenever the A/C is on.

Good luck!

grumpin

The VSV will shut off when the compressor does, so the idle will cycle with the compressor. Is your compressor still running when it idles down?

an1176

Yes it is. The guy that helped me said the compressor should never shut off. I was under the impression it should cycle... I know the compressor is still running because my idle will fluctuate between 200 and 600 several time until it settles at about 450. If I turn ac off idle goes back to 800 like it should.

grumpin

Could be that VSV is getting warm and shutting off. Did you try any others? You could connect the VSV lines together and see if the idle stays up and then you'll know it's the VSV.

Lono&theGremlin

*bump bump Hey can anyone tell me if the VSV on the 22R is the same as the VSV on the 22RE? Or more specifically is the wiring connector the same? I am swapping the AC system from a 22R into a 22RE truck and just trying to work out compatibility issues. Any other differences I should be aware of? I know I'll need the Idle-up diaphram valve for the RE as well. They are both 85 pickups. Thanks in advance