I have a 1998 Camry with a 4 cylinder engine.It has 102,000 miles on it.
I noticed today when the air conditioner is turned on,the idle speed drops way to low.All of my other Toyota,s idle speed gets kicked up when the air is turned on.
Is there an adjustment for this?
Any information would be great appreciated.
Thanks...Chuck

There's an "idle up" valve for the air conditioning.
You need to find it and check the vacuum line for cracks or looseness.
Sorry for not taking time to look this up, but I think you'll find it on the end of the intake manifold - facing the engine would be on the left side. That would be the collector part on top, not the individual runners.

Hello:Thanks for the information.
Is there a adjustment to the idle up speed?
Thanks...ChuckThere's an "idle up" valve for the air conditioning.
You need to find it and check the vacuum line for cracks or looseness.
Sorry for not taking time to look this up, but I think you'll find it on the end of the intake manifold - facing the engine would be on the left side. That would be the collector part on top, not the individual runners.

I got the same problem on my 88 Camry for couple years now. The AC clutch will disengage when idling since the rpm drops to about 500. But works good on highways.

Can you keep us updated how you are doing with that problem? Thanks.

I got the same problem on my 88 Camry for couple years now. The AC clutch will disengage when idling since the rpm drops to about 500. But works good on highways.

Can you keep us updated how you are doing with that problem? Thanks.
Hello all, I have a similar condition on my 1989 camry. The air conditioner seems to work fine only when the car engines speed (R.P.M.) is fast. when the car is just idling the compressor does not kick on for the A.C. The idle speed control valve was checked by me using the test procedure in the Hayes repair manual (BRIDGING TERMINALS T AND E1) while the engine was idling, and engine speed increased for about 5 seconds then went back to normal idle. the part seems fine. Does anyone else have any ideas what could be the problem. I seem to have the same problem with my A.C. as ProMan does on his 1988 Camry air conditioner. Any help/advice would be appriceated. Thank you... JOET/CAMRY

As previously mentioned, an idle up valve is likely culprit, there is no adjustment. The valve creates a small vacuum leak when the AC compressor comes on to increase idle speed.Either the hoses leak or the electrical portion of the valve doesn't work anymore, I replaced the one in my 89 Camry last summer to fix the idle problem as it wouldn't work electrically.

Hello all, I have a similar condition on my 1989 camry. The air conditioner seems to work fine only when the car engines speed (R.P.M.) is fast. when the car is just idling the compressor does not kick on for the A.C. The idle speed control valve was checked by me using the test procedure in the Hayes repair manual (BRIDGING TERMINALS T AND E1) while the engine was idling, and engine speed increased for about 5 seconds then went back to normal idle. the part seems fine. Does anyone else have any ideas what could be the problem. I seem to have the same problem with my A.C. as ProMan does on his 1988 Camry air conditioner. Any help/advice would be appriceated. Thank you... JOET/CAMRY


Same as mine. I tested the the valve and the engine rpm went up exactly as the manual described. So I am a little confused -- looks like the valve is working fine, but why it won't engage when the AC kicks in? Wiring problem?

The idle up valve for my 89 is on the passenger side firewall, the idle speed control test used will not indicate whether the idle speed will increase when AC compressor is on. Idle speed will only increase when compressor comes on and AC button is on. The idle up valve increases rpm and the computer reads the rpm increase and allows the AC compressor to stay on. If no increase in rpm the computer will shut off compressor till rpms increase.

The idle up valve for my 89 is on the passenger side firewall, the idle speed control test used will not indicate whether the idle speed will increase when AC compressor is on. Idle speed will only increase when compressor comes on and AC button is on. The idle up valve increases rpm and the computer reads the rpm increase and allows the AC compressor to stay on. If no increase in rpm the computer will shut off compressor till rpms increase.
Hello All, Just wanted to keep you all updated on the problem I was having with the ac on my 1989 Camry. The car would idle way too low when ac was on/engine idling. Most of the time the compressor wouldn't come on at all while engine at idle. On the highway or driving at a steady fast speed the air conditioner worked great!! I found out that it was most likely the ac idle up feature that wasn't functioning.The ac idle up valve is supposed to increase the engine speed (rpms) when the engine is at idle 1/2 second before the ac compressor comes on so the engine doesn't run rough/konk out. In my Haynes 83-91 camry repair manual it listed a procedure to test the idle speed control valve (isc) by bridging terminals T and E1 on the check connecter box. I jumped the terminals and engine speed increased to about 1300 rpms for 5 seconds then returned to normal idle just like the book said it should. I found out the IAC (idle air/speed control valve ) DOES NOT control the ac idle up feature for the older Camrys like mine from what I understand. The ac idle up on my car is located on the firewall on the passengers side of the engine compartment. the ac idle up a.k.a. (vsv) vacuum switching valve has 2 small hoses connected to the top of it and also a electrical plug with 2 wires on the bottom of part. I replaced this part with one from the local car junkyard; cost was $10.00 and presto.... AC WORKS GREAT NOW!!!! I found very useful information on this subject on the website www.autoshop101.com. Look under technical articles #21 efi-air induction systems. Thank you TYPESIX for your previous input on this subject. PROMAN might want to replace the ac idle up valve A.K.A. VACUUM SWITCHING VALVE (VSV) IN HIS 1988 CAMRY. Thank you everyone for your input. this messageboard is very informative. JOET/CAMRY

Woooooooow! Got it!

Yes, I think I mistake the IAC with the Idle-Up VSV. I took the 2 hoses off from the VSV and ASV. I can hear hissing from the ASV and feel the sucktion from one port. I connect the hose from that port directly to the other port and Voila! The engine revs up! I also measured the voltage of the wire connector, when the AC is on, one of the wire did have 12V.

So, now, as you guys pointed out, yes, I had pin pointed the problem to be the Idle-Up VSV. I will see if I can find one on the internet or from the local junk yard.

Thank you guys!!!

Woooooooow! Got it!

Yes, I think I mistake the IAC with the Idle-Up VSV. I took the 2 hoses off from the VSV and ASV. I can hear hissing from the ASV and feel the sucktion from on port. I connect the hose from that port directly to the other port and Voila! The engine revs up! I also measured the voltage of the wire connector, when the AC is on, one of the wire did have 12V.

So, now, as you guys pointed out, yes, I had pin pointed the problem to be the Idle-Up VSV. I will see if I can find one on the internet or from the local junk yard.

Thank you guys!!!
I was wondering what year the Camry started using the IAC (idle air/speed control valve) for the AC idle up feature on their cars? Am I right about this? late 90's? :confused: On the website www.autoshop101.com there is an interesting article on this subject under technical articles # 26 Engine Controls- Idle speed control ; page 14 on bottom of page. Just wanted to know for my own curiosity.. Also on my previous post I said the vsv (vacuum switching valve) was the ac idle up. I might of been partally wrong. :confused: I think the vsv and the asv (air switching valve) work together to form the ac idle up feature; in the older Camrys anyways. Any advice/information on this topic would be appriceated. Thank You.. JOET/CAMRY

Holy Houston!

I just called a dealership out of curiority to see how much a new AC Idle-Up VSV costs. It's $240! Kind of expensive for a small part like that.

I then called a junk yard, they ask for $10!

Hmm, I wonder which one I should choose....

All right! I got the VSV from a junk yard. $10. It feels so good that I have AC while waiting for traffic lights.....

All right! I got the VSV from a junk yard. $10. It's feels so good that I have AC while waiting for traffic lights.....
PROMAN.Nice going on getting the AC working on your 88 camry by replacing the vsv. Now the compressor kicks on and off as needed even when the engine is just idling. :grinyes:The dealership wanted $240.00 for a vsv? They can kiss my a$$ 10 dollars sure is alot more reasonable!!I'm sure you noticed both of the vsv hoses connect to the ASV (air switching valve). Thier is a big white screw located on the ASV that will adjust engine idle while the AC compressor is engaged. turn the screw counter clockwise and engine speed/rpm's will increase. turn the screw clockwise and engine speed/rpm's will decrease. I guess that adjustment is there in case the idle speed is too low when ac is on/compressor engaged; but you shouldn't have to screw with it :screwy: [no pun intended] Have a coool Summer. Take care.. JOET/CAMRY