5.0 not running too good with AC on!

John opined in news:ICe_a.33157$ snipped-for-privacy@twister.southeast.rr.com:

You have some weird problems and need to spend an afternoon with the hood up.

First, look for any cracked hoses or loose connections. Does engine speed change when you press brake?

then warm car up, disconnect the IAC connector and see if problem remains.. the idle will be erratic but you should be able to rule out that (erratic engine control) if it remains the same.

Still happening?... Rig a test light to the A/C clutch terminal.. see if the problem coincides with clutch cycling.

If so, probably bad ground at block - firewall, and/or the ground at the ECM itself.. pass. side kick panel.

exactly what I would expect it to do if it were out of refrigerant. That is EXACTLY what happened to mine when the refrigerant disappeared. The compressor was working very hard and cycling off and on.

Exactly, same thing happened to mine. Service your A/C. Be careful, running a compressor without coolant can damage it. Ford A/Cs aren't as smart as GMs in that they don't have any safety devices to prevent the compressor from running if there is not enough refrigerant.

Makes perfect sense. Is it pretty safe to assume that your A/C isn't blowing as cold as it should?

Wow, I didn't think of that; I'll have the refrigerant level checked right away. Thanks!

Victor DiMichina opined in news:3F3980B0.7030400@pixel_no_spammagicfx.com:

?????

1000 to 2500 rpm with A/C clutch cycle? I dont think so Tim... The 2.3's do "anticipate" like that, see no reason for the 5L to do that

Ummmm that's what that switch ASSY on the accumulator does,, the Clutch WILL NOT engage with no refrigerant... unless there's a bad switch. Low refrigerant DOES cause fast cycle.. because the pressure drops when compressor runs.

He MAY HAVE low refrig... but, unless he's exaggerating the other symptoms, that is not the whole problem.

Backyard Mechanic opined in news:Xns93D665812A28ABkMch6d@216.168.3.44:

DUH... typo:

The 2.3's DONT "anticipate" like that, see no reason for the 5L to ..

Are you actually suggesting that both John and myself are LYING? Do you actually think that we're imagining the whole thing? I haven't heard talk like that since I used to go to the Pontiac dealer for frequent fixes on my old Firebomb.

Ford has kindly replaced two compressors on my car because of this. When the compressor is trying to cool the car with low or no coolant, it gets damaged and starts making noise.

OK, so I started up my car today, without the AC on, and it did the 2500rpm rev thing!

It started fine, idled for a few seconds, then revved to 2500, held for about 4 seconds, then dropped back to 1000.

So, if it's doing this with or without the AC on, where should I look for the problem?

Thanks, John

Victor DiMichina opined in news:3F3A63F0.70102@pixel_no_spammagicfx.com:

If you say so

But my cars' A/C's will not engage (or stay engaged) with low refrigerant.

I certainly could be wrong.. I have been before, I will be again.

There are a couple professional ASE techs on alt.autos.ford.

Why not ask there.

OK, so I started up my car today, without the AC on, and it did the 2500rpm rev thing!

It started fine, idled for a few seconds, then revved to 2500, held for about 4 seconds, then dropped back to 1000.

So, if it's doing this with or without the AC on, where should I look for the problem?

Thanks, John

93 GT

It sounds similar to what my car would do when the IAC needed cleaning. I don't know if you followed BYM's advice about unplugging the IAC and seeing what effect it had at idle, but if unplugging that doesn't yield a change in the behavior, then it may be that the IAC itself needs cleaning. I had good luck simply unscrewing it and cleaning it with carburetor cleaner. The IAC is a pintle and seat valve that gets gummed with carbon, which affects its ability to seat properly, hence the 'hunting' effect. Mine would rev up, then drop down, then rev up, then drop down, until it eventually just died out on the rev down part. When you look into it, the valve should be shiny, not black. I simply sprayed the carb cleaner into it and covered the holes and shook it a bit, dumped it out and repeated the process until I was happy with it. You can also try using a cotton swab to gently clean some of the tougher spots.

Victor DiMichina opined

Well, see below, Vic. I said I didnt think that was the problem.

MAYBE the reason I said that is because I know how EECIV works.

John opined in news:67r%a.732$ snipped-for-privacy@twister.southeast.rr.com:

Sorry... someone should have responded to that by now

You probably have a sensor out of range, have the codes read out. If no codes, look at the TPS

Also check all harness ground point, particularly at the PCM pas side kick panel. All sorts of weird effects when this is loose or corroded.

Sounds to me like the ol' bad BAP sensor engine surge thing.

Just changed one of them barometric dohickies on a five-oh. Cured the problem lickity split. Expensive little bugger, though. About $120 from FoMoCo. Cleaning the ten pin connectors dosen't hurt none, either.

~phiz

GROSS POLLUTERS SoCal

~phiz opined in news: snipped-for-privacy@news.west.earthlink.net:

Good idea about the BAP...but that's onna those things that's either good or bad... not really a wear item.

And there's thousands of those in the junkyard looking for new homes.