1996 3.4L A/C not engaging at idle

[ryanbt]

I've searched existing threads, but I'm not finding exactly what I need. (Maybe I didn't use enough key words) So I'm hoping my friends at T4R.org can help me out:

Last week my '96 (w/195,600 miles) began idling poorly at about 300 - 400 rpm and CEL came on.
I took her to my local dealership and they replaced the TPS Sensor, Idle Air Control motor and cleaned the Throttle Body. She is purring like a kitten now and idles at about 700rpm. HOWEVER, the a/c will not engage at idle only unless I put my foot on the gas to nudge the rpm up to 800 - 900rpm.

What is the problem now, or can something be adjusted?

It's 105°F (41°C for our Canadian friends) and I don't want to have to sit at a red light with my foot on the gas in neutral after just replacing all of those parts.

 

[ryanbt]

Anybody? It's hotttttttt out.

 

[nissanh]

May be not enough gas?
Do you see the clutch in the AC compressor running while at idle?

AC compressor is only controlled by the temp. control module attached to the Evaporator inside the cabin.

 

[Singtoe]

Sounds like your are low on freon. The Ac seams to be working on when you give it gas meaning your compressor is pumping enough freon to suppy the ac system with preasure.

check you sight glass and see if you have any bubbles.

 

[opie74]

Need to know if the compressor is spinning at idle or not. In addition to the temp probe on the evaporator, there is a pressure switch in the engine bay near the low side port. If the compressor is spinning at idle and the air gets colder when you increase engine speed, most likely its low on charge/ not enough air flow over the condenser.

If the compressor is not spinning at idle and it kicks in when you increase engine speed, thats weird. That could be a slipping clutch. What is the vent outlet temp coming out of the center vents?

 

[ryanbt]

Sight glass shows no bubbles. I'll take it back to the dealer tomorrow and see what the deal is. It is ice cold when you are driving around, even if you are at 5 mph.

 

[ryanbt]

Turns out it was the AC clutch!

 

[ryanbt]

So I picked it up (supposedly fixed) and it's still doing the same thing. Freon level is fine and I have a new A/C clutch. When at idle (800 or so rpm) with driver's door open you can turn the A/C on and you do not hear the A/C engage. If I bump the idle up to about 1300rpm with my foot holding steady on the gas pedal and then turn the A/C on you hear the system engage and it starts blowing out ice cold air and my foot induced idle drops 100 or so rpm. Keeping my foot steady on the gas I turn A/C off and "idle" returns to 1300rpm.

I want to take it back to them to have them look at it again, and I want to show them exactly what I outlined above but am hoping my T4R.org buddies may have some further insight that I can share with them. I've dropped $1500 into her in the last week and am not really feeling like spending any more. If it's truly the compressor, heck it's almost fall. Ill just wait until spring to replace that.

 

[nevada]

what did it idle at before you had it worked on?

did the ac work at idle before?

i dont know about that generation of truck, but on the earlier ones, theres a switch behind the glove box, that you can turn to adjust at what rpm the clutch engages.

 

[ryanbt]

No it didn't work before, at the idle was low which is why I took it in for the TB to be cleaned, TPS Sensor and new Idle Air Control module.

 

[nevada]

No it didn't work before, at the idle was low which is why I took it in for the TB to be cleaned, TPS Sensor and new Idle Air Control module.

check behind the glove box.
you might have to remove it to see in there.
like i said, i dont know if that truck has it, or if its even in the same spot.
but my 4runner was doing the same thing. all i had to do was turn the knob a tiny bit, and fixed it.

 

[Singtoe]

So I picked it up (supposedly fixed) and it's still doing the same thing. Freon level is fine and I have a new A/C clutch. When at idle (800 or so rpm) with driver's door open you can turn the A/C on and you do not hear the A/C engage. If I bump the idle up to about 1300rpm with my foot holding steady on the gas pedal and then turn the A/C on you hear the system engage and it starts blowing out ice cold air and my foot induced idle drops 100 or so rpm. Keeping my foot steady on the gas I turn A/C off and "idle" returns to 1300rpm.

I want to take it back to them to have them look at it again, and I want to show them exactly what I outlined above but am hoping my T4R.org buddies may have some further insight that I can share with them. I've dropped $1500 into her in the last week and am not really feeling like spending any more. If it's truly the compressor, heck it's almost fall. Ill just wait until spring to replace that.

Take it back. Especially if you paid $1500 to have it repaired. Spend no more money.

Sounds like clutch was a misdiagnosis on their part.

 

[opie74]

I want to take it back to them to have them look at it again, and I want to show them exactly what I outlined above but am hoping my T4R.org buddies may have some further insight that I can share with them.

There have been some specific questions asked that have gone unanswered. Cant help without specifics.

 

[ryanbt]

Do you see the clutch in the AC compressor running while at idle?

I don't know how to check for this.

check behind the glove box.
you might have to remove it to see in there.
like i said, i dont know if that truck has it, or if its even in the same spot.
but my 4runner was doing the same thing. all i had to do was turn the knob a tiny bit, and fixed it.

I've been trying to find out if the 3rd gens have this... But still have no answer.

Need to know if the compressor is spinning at idle or not. In addition to the temp probe on the evaporator, there is a pressure switch in the engine bay near the low side port. If the compressor is spinning at idle and the air gets colder when you increase engine speed, most likely its low on charge/ not enough air flow over the condenser.

If the compressor is not spinning at idle and it kicks in when you increase engine speed, thats weird. That could be a slipping clutch. What is the vent outlet temp coming out of the center vents?

I'm starting to lean towards Temp Probe on Evaporator or Pressure Switch..

I also lurked over at yotatech and found this (fixed high idle now ac clutch wont engage - YotaTech Forums) but there isn't a resolution yet.

I agree with singtoe. I am going to take it back because of the $$ I've spent and the misdiagnosis.

 

[ryanbt]

Update: Dealership called and said they had to open a special case with Toyota as they had never seen this issue before. They said they also don't have a ball park figure on how much it would cost yet. Since I've dumped $4500 in it in the last year, I'm going to take it upon myself to figure it out from here. I'll probably wait awhile now that Fall is upon us, but will start with buying a new amplifier, and then move on to the pressure switch and hopefully figure it out by next May!

 

[Singtoe]

Wow, your stealership is dumb. Did they refund you back your money. Sounds like small claims court is in your future.

I don't believe your year model has an ac ampilfier. Don't go spend a lot of money that you don't have too.


If you would, verify that the clutch (Center part of AC compressor should be spinning) is engaging at idle.

 

[BlackWorksInc]

There is an AC Amplifier listed in the repair manual, not too sure if I would consider that the culprit.

That's a very strange problem, but I highly doubt the RPM is anything more than coincidental, about the only way I can see it relating is if the clutch is not functioning properly so when you rev it up it spools the compressor more.

I want to say that I think either a pressure sensor or the compressor is at fault, it seems to be pressure dependent in the sense that when you apply more revolutions per minute you're applying the compressor to pump longer at a higher pressure.

You mentioned that they replaced your a/c clutch, just the clutch? Not the whole unit?

 

[nevada]

There is an AC Amplifier listed in the repair manual, not too sure if I would consider that the culprit.

That's a very strange problem, but I highly doubt the RPM is anything more than coincidental, about the only way I can see it relating is if the clutch is not functioning properly so when you rev it up it spools the compressor more.

I want to say that I think either a pressure sensor or the compressor is at fault, it seems to be pressure dependent in the sense that when you apply more revolutions per minute you're applying the compressor to pump longer at a higher pressure.

You mentioned that they replaced your a/c clutch, just the clutch? Not the whole unit?

are you saying its strange for that particular vehicle?
because for SURE thats what mine was doing.
turned the knob a tiny bit, and it was good to go.

maybe it had gotten bumped when someone was working under the dash? i have no idea. i just know mine was doing the same thing, compressor not kicking in at idle.

 

[ryanbt]

There is an AC Amplifier listed in the repair manual, not too sure if I would consider that the culprit.

That's a very strange problem, but I highly doubt the RPM is anything more than coincidental, about the only way I can see it relating is if the clutch is not functioning properly so when you rev it up it spools the compressor more.

I want to say that I think either a pressure sensor or the compressor is at fault, it seems to be pressure dependent in the sense that when you apply more revolutions per minute you're applying the compressor to pump longer at a higher pressure.

You mentioned that they replaced your a/c clutch, just the clutch? Not the whole unit?

Comments from invoice:

Idle Air Control Motor sticking. Malfunctioning. Recommend TPS sensor also be replaced due to age/wear/mileage. Remote throttle body assembly and replace Idle Air Control motor, Throttle Position Sensor and gaskets as needed.

Perform complete fuel system service. Clean top engine and valves, clean throttle body.

Bad fan clutch, replace fan clutch. Charged freon, service AC.

They also opened a case with Toyota because they had never experienced this issue.


Parts that were replaced were:

08921-04950, Fan Clutch.
22270-62050, Idle Speed Control Motor
22215-62180, Gasket
22271-62040, Gasket Throttle
89452-35020, Throttle Sensor
00263-00134-01, Warranty? - Not sure what this is
00289-INDKT, Induction Kit.

Comments from invoice:

Idle Air Control Motor sticking. Malfunctioning. Recommend TPS sensor also be replaced due to age/wear/mileage. Remote throttle body assembly and replace Idle Air Control motor, Throttle Position Sensor and gaskets as needed.

Perform complete fuel system service. Clean top engine and valves, clean throttle body.

Bad fan clutch, replace fan clutch. Charged freon, service AC.

They also opened a case with Toyota because they had never experienced this issue.

are you saying its strange for that particular vehicle?
because for SURE thats what mine was doing.
turned the knob a tiny bit, and it was good to go.

maybe it had gotten bumped when someone was working under the dash? i have no idea. i just know mine was doing the same thing, compressor not kicking in at idle.

I don't think the third gens had this. I looked behind the glovebox and didn't see anything that looked like what you were talking about.

 

[LittleCaesar]

Here is a clear case of why dealerships are earmarked as stealerships; Ryan does the right thing in his mind, pays $$$, and still there is no fix for the problem that was looked at by professionals, so to say.

Not only did they throw parts at this problem, they did not even replace the possible problematic components. There should be part# 88412-35090 if they replaced the magnetic clutch/stator, which, instead, they chose to replace the fan clutch. Why? There is an amplifier on the side of the case on the passenger side BTW.

I'd take it to a dedicated AC shop, get them to give you an estimate of the possible problem(s), and then have the stealership pay for it. Lawyer up if need be. Or have the stealership fly Singtoe first class out there to repair it.