This is an odd one to describe.
I think the IAC may have failed. But only seems to have the problem under a very specific circumstance.
In January, I pulled the AC relay. I do this because when the temperature drops below freezing, it all leaks out around the schrader valve.
With no AC relay, when any one of the blue settings on the HVAC are selected (anything with defrost, face / feet) it will just bump the idle up indefinitely until HAVC is put on a non-ac setting or turned off.
Normally, it would just idle down to 650. I noticed it would just stall when I turned the HAVC off when I wasn't on the throttle.
Note, at this point, the AC Compressor wasn't engaging.
This kept happening on and off. It idles fine with the AC off. I can get on the gas and off the gas, rev it up and it won't stall when it comes back down. Can cycle through the gears with AC either on and off (no relay) with no problem.
Last night I recharged the AC. Blows ice cold now.
However, every time it dis-engages the AC compressor clutch it either tries to stall or will stall. Certainly was interesting trying to recharge it or drive it in traffic when it would stall at stop lights.
First I thought that maybe the AC clutch was getting stuck. I can see the compressor stop spinning before it stalls. The computer will disengage the clutch, then a second later try to (unsuccessfully) bump the idle back down.
The compressor itself is fine and makes no noises. The engine has no problem idling when it kicks on.
TPS is fine. With no throttle it is at 16% open, wide open throttle (key on, engine off for both), it is at 65% which seems to be normal - it's even all the way throughout the pedal travel.
I want to think it's the IAC, but seems to be a bit odd that it only happens when the ac disengages (or the computer thinks that there is a ac clutch running). I did fix a few vaccuum leaks back in April and I reconnected the airbox as the intake tube was lose to the throttle body.
Engine runs VERY smooth for it's age and mileage.
Any ideas?
I think the IAC may have failed. But only seems to have the problem under a very specific circumstance.
In January, I pulled the AC relay. I do this because when the temperature drops below freezing, it all leaks out around the schrader valve.
With no AC relay, when any one of the blue settings on the HVAC are selected (anything with defrost, face / feet) it will just bump the idle up indefinitely until HAVC is put on a non-ac setting or turned off.
Normally, it would just idle down to 650. I noticed it would just stall when I turned the HAVC off when I wasn't on the throttle.
Note, at this point, the AC Compressor wasn't engaging.
This kept happening on and off. It idles fine with the AC off. I can get on the gas and off the gas, rev it up and it won't stall when it comes back down. Can cycle through the gears with AC either on and off (no relay) with no problem.
Last night I recharged the AC. Blows ice cold now.
However, every time it dis-engages the AC compressor clutch it either tries to stall or will stall. Certainly was interesting trying to recharge it or drive it in traffic when it would stall at stop lights.
First I thought that maybe the AC clutch was getting stuck. I can see the compressor stop spinning before it stalls. The computer will disengage the clutch, then a second later try to (unsuccessfully) bump the idle back down.
The compressor itself is fine and makes no noises. The engine has no problem idling when it kicks on.
TPS is fine. With no throttle it is at 16% open, wide open throttle (key on, engine off for both), it is at 65% which seems to be normal - it's even all the way throughout the pedal travel.
I want to think it's the IAC, but seems to be a bit odd that it only happens when the ac disengages (or the computer thinks that there is a ac clutch running). I did fix a few vaccuum leaks back in April and I reconnected the airbox as the intake tube was lose to the throttle body.
Engine runs VERY smooth for it's age and mileage.
Any ideas?