[saerandy]

1997 GL - I'm experiencing a significant stumble every 10-40 seconds when the AC is turned on. There's no odd noise coming from the engine compartment. It is not the compressor starting up. It's happening when the compressor is running. This 'stumble' can be felt as a 'shudder', and the tach moves a bit.

Air is blowing as cold as ever. I bought a can of AC "tune-up" at Advance Auto Parts, but haven't added it yet.

Has anybody had this? Also - Where would I inject this can of snake oil? Is the port to recharge the system the one that's near the firewall on the passengers side?

Help!!

 

[saerandy]

Anyone? At least tell me where the low pressure access port is. . . .

 

[Rockledge]

QUOTE

Is the port to recharge the system the one that's near the firewall on the passengers side?[/b]

Yes.

 

[saerandy]

Any ideas anybody? How about guesses?

 

[gtx2000]

should be on the firewall on the A/C lines you just follow them around youll end up finding it sooner or later it has a 2 pins plug on it. WHen was the last ime you cleaned the IAC and gave it a tune up?

 

[saerandy]

Not sure about the IAC, but the engine is new - Only 3000 miles on it.

This is only happening when the air is on and I'm idling at a stop. Likely it's noticable because the rpms are so low. It isn't the ac kicking on and off either. This just started a few days ago.

Nobody seems to have any idea what this might be (or else they're not posting the answer)

 

[TheGreatZambini]

I'm putting my brain to this one.

My wife's Saturn does the same thing.

 

[Rockledge]

The PCM and IAC are supposed to correct for increased/decreased engine load while the engine is at idle. So yes it is possible that the increased AC load is not being accounted for...

3000 miles means it's new. Is the IAC new, as well?

 

[gtx2000]

Whats the motor out of? Did you replace the upper intake manifold? Should check too see if there is any codes in the Computer

 

[TazTaurus]

I have a similar problem with my car and today it died for the first time when I used the A/C. It only happened once but nontheless, I'm concerned that it will happen again and I won't be able to start up again. I haven't had the time to check the car out but it could be a variety of issues ie. vacuum leak,bad battery, etc. The car has been recently tuned with new plugs, wires, dist cap/rotor. The battery is about 7 years old though I tested it with a multimeter and it seems fine and the alternator is supplying charge to the battery.

oh, how easy is it to disconnect and clean the IAC???? It's located near the throttle body right??

 

[saerandy]

The engine is a reman so everything that is typically new and the rest was swapped over from the old engine with the exception of things like the water pump and so-forth. I don't think the IAC is new.

Seems to do it worse when it is hot outside, but as you know that shouldn't matter too much as in the Bulls the AC is on or it is off. Maybe it works harder when it's hot?

Given that it is march, we're not talking about hot as in 80 degrees. I mean like the difference is between 60 degrees and 70 degrees.

The check engine light isn't on or anything, so I'll have to see if any codes are coming up next time I drive past The Zone.

I'm surprised this hasn't affected anybody else's Taurus. Strange. . .

 

[eagle888]

If your car has an AC Cycling Switch, maybe it's bad or it's signal is not getting into the PCM. This switch tells the computer that the AC clutch has kicked in and to adjust the idle (raise) to compensate.

 

[ffvulcanpowah]

My car will shudder if i turn the a/c on at idle. The only way i have found that stops this, is if i turn on the a/c when the car is above 1500 rpms. Then there is no shuddering. Also, my idle wont raise when i turn on the a/c, it actually lowers.

 

[saltlakedave]

QUOTE

I'm surprised this hasn't affected anybody else's Taurus. Strange[/b]

LOL - dont be so sure. I have the same problem.. Not exactly, but at idle with when the rad fan turns on, it starts fluctuating.. Stupid car!! Dealership was just scratching their heads because of course, it didnt do it when they had it

It's got to be something with some part of the load compensation system with yours.. As for me.. its not the a/c that does it. :-( Its only if I have the heater/a/c controls in any other position besides off. Then when the rad fan kicks on, it starts fluctuating. (2002 ses)