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porcellr
July 18th, 2005, 19:52
A/C works fine but when I hit the gas hard or have to drive up a hill. The vents blow hot air. When just cruiseing all is fine

1989 Jeep

BAs96XJ
July 18th, 2005, 20:03
My guess is vacuum leak. Check all you vacuum lines and canister. When you gas it the engines sucks all the vacuum and switches the vents to heat instead of cool.

BA

Atl XJ
July 18th, 2005, 20:15
Yeah, the "vacuum canister" effects this. If its not functioning properly or it is unhooked your Jeep will demonstrate those symptoms. Alot of people unhook them when they install aftermarket bumpers since its mounted behind the bumper and it wont fit behind some of the aftermarket bumpers.

Sorry I couldnt remember the name of it when you asked this on JU.

http://jeepin.com/features/canister/index.asp

fordtech
July 19th, 2005, 04:22
WOT shuts off the a/c in 99% of the vehicles ive ever worked on. 2 reasons: more power and to fight overheating.

Matthew Currie
July 19th, 2005, 06:55
WOT shuts off the a/c in 99% of the vehicles ive ever worked on. 2 reasons: more power and to fight overheating.

I don't recall that this is the case with the 89 4.0, but I'm pretty sure it is with the 2.5. The original poster doesn't specify what Jeep he has.

Jeff in VA
July 19th, 2005, 07:00
Also, a sudden WOT condition dramatically increases the compressor RPM's, which in turn creates a big, sudden drop in suction pressure. The WOT relay disengages (nromally closed) and cuts power to the compressor as a safety precaution.
Jeff

XJXJ
July 19th, 2005, 07:07
The original poster doesn't specify what Jeep he has.

They never do - It seems most people can't even organize thoughts long enough to express what they need for help? That's scary! It would be nice if folks would show proper respect for the technology and information sharing process.

Oh well, I don't think Renix switched-off compressor under WOT either. The ECU switches into open-loop mode under WOT but I've never seen it kick the AC off.

The FSM gives these possibilities for A/C air flow Stops on Acceleration -

Defective vacuum storage tank

Vacuum line seperated or defective

Vacuum switch defective

Vacuum leak

You are probably on the right track with vacuum system.

Jeff in VA
July 19th, 2005, 08:25
Oh well, I don't think Renix switched-off compressor under WOT either. The ECU switches into open-loop mode under WOT but I've never seen it kick the AC off.



Yep, I spoke too soon. Checked the pinouts for the Renix (both 4.0 and 2.5) that I have and there's no WOT relay in the circuit at all. Just the main AC relay and the pressure cycling switch.
Sorry 'bout that, my MJ is non-AC and I assumed the system was controlled like most others.
Jeff

XJXJ
July 19th, 2005, 09:26
Yep, I spoke too soon. Checked the pinouts for the Renix (both 4.0 and 2.5) that I have and there's no WOT relay in the circuit at all. Just the main AC relay and the pressure cycling switch.
Sorry 'bout that, my MJ is non-AC and I assumed the system was controlled like most others.
Jeff

That's cool of you to post a correction and in most EFI instances A/C=off @ WOT. My guess is that Renault probably didn't have much A/C control experience at the time they put this system together.

coach9119
July 19th, 2005, 09:45
WOT? Sorry, but what is that?

Atl XJ
July 19th, 2005, 09:46
WOT? Sorry, but what is that?

Wide Open Throttle

coach9119
July 19th, 2005, 09:52
Thought of after I posted, thanks

csr_011
July 19th, 2005, 11:52
WOT? Sorry, but what is that?


With Out Toiletpaper...Talk about a shitty situation....:D:D

Cory