1st & 2nd Generation (1983–1986 & 1987-1991)Toyota Camry Discussion for years: 1983-1986 & 1987-1991.
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For some time now, i have noticed that the engine, when at idle, hunts (goes up and down between 500 and 1000rpm).
I had initially thought it was attributed to the a/c air control valve, located on the intake mani, that works in conjunction with the solenoid. The a/c tech had told me that i needed to change it as it was defective (he said the solenoid is good though).
However, i just happened to take a look under the hood while it was hunting one day, and i saw that everytime the idle went down to 500rpms the compressor's clutch disengaged, then when it went back up towards 1000rpms, it engaged, and it continued that cycle unless i revved the engine or switched the a/c off.
I was wondering what could be the cause of this, cuz somehow i don't think the a/c control valve is the culprit, as it only does this sometimes (not very frequently either).
I am wondering if it is becuz i use the ECON feature where the compressor chips in and out and it might be malfunctioning. I haven't tried it on A/C to see if it still does it becuz as i said before, it doesn't happen very often. But i do use the ECON more cuz it helps with conserving the cane juice (E-10).
For some time now, i have noticed that the engine, when at idle, hunts (goes up and down between 500 and 1000rpm).
I had initially thought it was attributed to the a/c air control valve, located on the intake mani, that works in conjunction with the solenoid. The a/c tech had told me that i needed to change it as it was defective (he said the solenoid is good though).
However, i just happened to take a look under the hood while it was hunting one day, and i saw that everytime the idle went down to 500rpms the compressor's clutch disengaged, then when it went back up towards 1000rpms, it engaged, and it continued that cycle unless i revved the engine or switched the a/c off.
I was wondering what could be the cause of this, cuz somehow i don't think the a/c control valve is the culprit, as it only does this sometimes (not very frequently either).
I am wondering if it is becuz i use the ECON feature where the compressor chips in and out and it might be malfunctioning. I haven't tried it on A/C to see if it still does it becuz as i said before, it doesn't happen very often. But i do use the ECON more cuz it helps with conserving the cane juice (E-10).
hELP!
Well I had a very similar problem and this is going to sound crazy but it worked.
Do you know what type of refrigerant you are using i.e r-12 or have you had the system converted to R-134a? What I found this problem to be on my car was that the compressor was working really hard and caused this as well. It wasn't just happening to me when i was idling, when driving i could turn the ac off and it was like hitting a turbo button on my car because my engine was working so hard to compress R-12.
Now in normal operation the compressor will cause the engine to reve up quite significantly in my case almsot 1200rpm and then drop down to 600 when the compressor would disengage and then continue to go up and down as long as i had the ac on. So here is my fix. You have one of two options. Your compressor is showing its age badly so you can replace your compressor or upgrade and postpone a costly repair. I converted the system to R-134a and put in synthetic R-134a with sub zero. Now i have realitivly normal operation of my compressor and my engine isn't struggling to compress R-12 which takes a great amount of pressure. Plus its like an ice box in my car. Nice and chilly my last temp reading while the compressor was engaged was 43F while running at 700rmp.
sounds normal to me in ECON mode it cycles the compressor on/off mine goes to around 1200 when compressor's on.. if you press AC it'll be constantly on
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Quantum mechanics - the dreams that stuff is made of.
Where does it idle with the A/C completely turned off?
Where does it idle with the A/C fully ON (not in any econ mode).
I bet that you are percieving it a little wrong. The idle should go up to around 1000 when the A/C is on and drop to around 600 when the A/C is off.
If the A/C is cycling on and off quickly (which may be a problem in itself...), then it would cause the idle to hunt as a side effect.
-Charlie
1. With the a/c completely off it idles at around 650rpm with the transmission in the D range. When the tranny is in park (with a/c off) it idles near 1000rpms at operating temp.
2. With the a/c on and the tranny in D, it goes lower maybe to 500rpms, sometimes til the car starts to vibrate.
This is what i was trying to explain. When i had the a/c tech re-gas the system, he rebuilt the compressor (had bad bearings and stuff) and he told me that the valve on the IM was bad, therefore when the a/c was turned on, the idle would not "step up" as it should. So what i believe happens is the extra load the compressor etc has on the engine carries down the rpms to that low 500.
So what could cause the a/c to be cycling on and off so rapidly, could it be this same vacuum operated valve on the IM?
Well I had a very similar problem and this is going to sound crazy but it worked.
Do you know what type of refrigerant you are using i.e r-12 or have you had the system converted to R-134a? What I found this problem to be on my car was that the compressor was working really hard and caused this as well. It wasn't just happening to me when i was idling, when driving i could turn the ac off and it was like hitting a turbo button on my car because my engine was working so hard to compress R-12.
Now in normal operation the compressor will cause the engine to reve up quite significantly in my case almsot 1200rpm and then drop down to 600 when the compressor would disengage and then continue to go up and down as long as i had the ac on. So here is my fix. You have one of two options. Your compressor is showing its age badly so you can replace your compressor or upgrade and postpone a costly repair. I converted the system to R-134a and put in synthetic R-134a with sub zero. Now i have realitivly normal operation of my compressor and my engine isn't struggling to compress R-12 which takes a great amount of pressure. Plus its like an ice box in my car. Nice and chilly my last temp reading while the compressor was engaged was 43F while running at 700rmp.
I'm not sure what type of refrigerant is currently in the system. I had thought that R12 was phased out. But i can't say for sure that i know what the tech had gassed it up with.
The car cools very nicely, sometimes i have to take it off the auto climate control to the manual fan speeds to turn it down for fear that my fingers, nose and ears will freeze off. lol. However when i'm in traffic or stopped at say a traffic light, the air goes warm-ish ( which i think is attributed to the low idle speed). But otherwise, it blows very cold even on a hot Jamaican day.
I can surely say though, that it does not suck that much power from the car. Sure it's noticeable, but not that significant to what you described. Even with the a/c on, the car still has good power. & i had the compressor rebuilt before i had the system re-gassed.
sounds normal to me in ECON mode it cycles the compressor on/off mine goes to around 1200 when compressor's on.. if you press AC it'll be constantly on
Ha ha, okay. When i have the a/c in econ mode and the tranny is in park, i see the normal cycling operation. The car will idle between 800-1000rpms for maybe 7-10 seconds, then the compressor comes in and it would drop to about 600rpms and the cycle would continue. Apart from the idle going down when the compressor comes in instead of up, it operates pretty normal as far as i see.
But the issue i have, is that, SOMETIMES, the compressor chips in and out frequently, in other words, it's clutch stays engaged for like a second before disengaging and it continues on and off, on and off, until i rev the engine or turn the a/c off. But as i said earlier, this is not a regular occurrence. It mostly runs okay apart from the low idle speed when the a/c is on.
The AC solenoid is probably bad on your car. (but the tech said the opposite, right?)
Most of the cars in the junkyard I tested when I was looking for a replacement for mine a couple years back were bad. Either find a good used one or pay up for a new one. It is easy to test with a multi-meter though. If you read an open circuit, between the two terminals, the solenoid is bad, otherwise it should be working (I think it is supposed to be 40-60ohms when working).
The valve on the intake manifold that is operated by the vacuum from the solenoid is adjustable to get decent idle-up and smooth on/off A/C performance. Adjust as necessary with the big screw on the front.
The AC may be cycling on and off due to a lack of pressure due to low RPM or something, so get the AC idle-up working first.
-Charlie
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2003 Impreza WRX Wagon 5spd - 2.2L stroker + other goodies
1989 Camry Alltrac LE 3S-GTE 5spd - SV25/ST205 hybrid
1990 Camry 3S-GTE 5spd - parted out / junked
1990 Camry DX 3S-FE 5spd - The original white90dx; gone but not forgotten
The AC solenoid is probably bad on your car. (but the tech said the opposite, right?)
Most of the cars in the junkyard I tested when I was looking for a replacement for mine a couple years back were bad. Either find a good used one or pay up for a new one. It is easy to test with a multi-meter though. If you read an open circuit, between the two terminals, the solenoid is bad, otherwise it should be working (I think it is supposed to be 40-60ohms when working).
The valve on the intake manifold that is operated by the vacuum from the solenoid is adjustable to get decent idle-up and smooth on/off A/C performance. Adjust as necessary with the big screw on the front.
The AC may be cycling on and off due to a lack of pressure due to low RPM or something, so get the AC idle-up working first.
-Charlie
I had already purchased a used solenoid from another camry and replaced the one that came on the engine when i first purchased the car, But i'm not sure, maybe the one i bought ain't working either, it did come from a newer model camry than mine, but i was told it could work by the person i bought it from, it also looked very similar to the one i had in before.
Then the a/c tech told me the solenoid was good, but the vacuum valve was bad, he even showed it to me by turning that big plastic screw at the front of it and nothing happened to the idle. No response, unless the screw was removed entirely.
Kinda confused now, should i get the vacuum valve replaced, or buy another solenoid.
Kinda confused now, should i get the vacuum valve replaced, or buy another solenoid.
Simple debugging should answer that question for you.
Bypass the solenoid with the vacuum line. (connect directly between the manifold vacuum port and the bypass valve). If the bypass works, its the solenoid.
Test the resistance of the solenoid as I described above.
Then figure out what you need to replace.
-Charlie
__________________
2003 Impreza WRX Wagon 5spd - 2.2L stroker + other goodies
1989 Camry Alltrac LE 3S-GTE 5spd - SV25/ST205 hybrid
1990 Camry 3S-GTE 5spd - parted out / junked
1990 Camry DX 3S-FE 5spd - The original white90dx; gone but not forgotten
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