Well, I'm having some A/C problems right now- hard compressor cycling, etc., but it also appears that something else is amiss. Occasionally, the car feels like the throttle setting is changing even when accelerator pedal position is constant. Has anyone seen anything like this? Is there some sort of throttle position sensor that goes out with symptoms like this? Unfortunately, it's been 100+ degrees here for awhile now, so I can't be COMPLETELY sure that it's not the compressor dragging the engine down with the hard cycles, but the wife thinks it's happening to some extent without the A/C on. We haven't ever had any tranny problems, so I'm hoping it's not slipping or anything like that. Unfortunately, she's usually the one driving and explaining this stuff to me, and you all know how that goes! But, she hasn't mentioned ever hearing the motor race when the tach jumps around and you FEEL the RPM changes...

Any ideas or epxeriences like this?

 

When the A/C comes on, the RPM goes up to compensate for the additional load

 

the tps is easy to test if you have a multimeter so you should check that first. i need to replace mine.

 

In park, I held the throttle at about 2500 rpm, and while holding it there, turned the A/C on. The rpm dropped almost 500 rpm. That seems a little excessive to me.

 

try energizing the clutch and turning the compressor manually you won't think that it's such a steep drop then

 

I've owned the car for 5 years, and I've never noticed it as pronounced as it is now... I mean, if it drops 500 rpm in park at 2,500 rpm, wouldn't it KILL the engine if it cycles at idle? It usually only drops like 150 rpm or so when it cycles at idle.

Anyway, wife's got a mechanic appointment tomorrow morning for it. I'm lubing up in preparation...

 

did you clean the IAC valve?

 

Umm, no. Don't know what/where it is. I am not real familiar under the hood of this thing, as it a) rarely gives me trouble, and b) spend all my tinkering time with my Powerstroke diesel and our ATV's.

I've got a manual (aftermarket) at home. Is cleaning the IAC a fairly quick job? If so, I'll try and do it quickly tonight and see if it helps...

Thanks again.