[Done]

Help, I have a problem. I have a 97 Escort automatic with 90,000 mi.

I live in Minnesota so if this has been a problem longer I don't know, but it only happens above 70 degrees or so. If it's below 70(maybe 65) I don't notice it.

Once the engine warms up It begins to hesitate on lower speeds. (45 and lower) It will occasionally kill at a stop sign, and will not want to remain running. This is only periodically but only in warmer temps!

I don't notice any vacuum leaks, recently had a tune-up and fuel filter replaced. Any info would be great! Thanks

 

[highanddry]

Does your Check Engine light (or Service Engine Soon in your case) light come on when it dies?

 

[highanddry]

Sorry...sent to soon. Warm air is less dense. This is likely a case of your engine running to rich or at least your computer thinking that (air flow sensor may be faulty). Have your codes read (if you're getting any) and a shop should be able to find your problem in no time with the description you provided.

 

[Done]

re-visited

Hey, thanks for the info. Today I found out some more. The AC fuse was loose and not connected, when I put it back in it began to run worse.

I put it in while I was moving, the idle/rpms were going up and down, the car eventually killed.

The hesitating seems better with the fuse in, but only when the blower/defrost/ac switch is off. If it is on it will kill

I hope this sheds a little more light on the problem.

by the way, the ac does blow cold air.

 

[highanddry]

I'm sticking with my original suggestion. When you turn your A/C on, the computer tells the engine to rev a little higher to accomodate the increaded load. That is why your rpm's fluctuate a bit when loads change (ie A/C turning on and off). Additional loads will magnify the problem such problems as an improper air/fuel ratio or vacuum leak.

You didn't say whether your SES light comes on when your car dies. If it is; have your codes read and your problem will be obvious.

Let us know what you find.