A/C Cold Air Only When Accelerating

[joehero]

I have a 2001 Explorer Limited with EATC and I have searched this forum high and low and I have found the blower motor issue and the blend door issue and I will likely have to change my blower motor controller as well, but my issue goes further.

So first off, my unit will only work on high. That is one issue which I have found alot of info on. But the real problem is that the A/C will blow cold air at first sometimes, but it always cuts out. However, if we turn off overdrive or are applying gas and working the engine, we get cold air.

Can anyone point me in the right direction? I don't think it is the blend door unless the acceleration is jarring it back into position somehow.

I appreciate any help you can give me.

 

[dogfriend]

Never mind.

 

[01sporty]

check that you have the proper amount of refrigerant when they are low on refrigerant they will act that way

 

[my98nnj]

The temperature blend door does not operate on vacuum it operates via a small electric motor. That's not his issue.

Have an a/c tech put a set of manifold gauges on it. That will tell you exactly what's going on.

 

[fsumotorhead]

I think that you have a vacuum leak somewhere. What is happening is that under acceleration (high engine load) you create enough vacuum so that the blend door moves to the correct position. At other times when you aren't accelerating, there is not enough vacuum stored to operate the door. I would look at the vacuum lines going from the firewall to the vacuum storage container that is located in front of the passenger side (right side) front wheel. The plastic container could be cracked or one of the lines could be cracked.

this is exactly backwards, engines have the most vacuum at idle (throttle closed), and no vacuum at WOT.

 

[dogfriend]

this is exactly backwards, engines have the most vacuum at idle (throttle closed), and no vacuum at WOT.

You are correct, I had it backwards. Never mind.