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Low idle

My car has suddenly started idling really low which leads the engine to cut off when I am not accelerating. The engine also frequently dies when I turn off the A/C. Any suggestions?

What kind of car? What year? Mileage? Do you keep you with your maintenance? Automatic or manual? F/I or carb? Is this always the case? Does it do it when just started-up or after it has warmed-up? Rocketman

2001 mitsubishi diamante, mileage approx. 117500, automatic. Can’t afford to keep up with maintenance all the time…I do what I can when I can afford to. F/I or carb?? Engine does not cut out every time, but it does frequently. Started about 2-3 weeks ago. If the idle dips real low it kind of starts to sputter, then I try to hit the gas a little to keep the engine going. I do not usually drive my car for long distances so, it often does not have that much time to warm up. Sometimes it starts right away and sometimes it takes a few miles before it starts acting up. Thanks for any help you can give me!

Is the check engine light on?

Honestly, it has been on for the last year or two. I had it checked a long time ago and they said it was a heat sensor that was causing the check engine light to be on. I didn’t have the money to fix it and the car has been running fine for the last year or two until just a couple weeks ago.

The best thing to do is go have the codes read - large auto parts chains will normally do this for free.

Whatever codes you had before should be in there, and there will likely now be others. Have them read, write them down (the actual codes, like P0123, not what anyone says about them), and post them back up here.

When the check engine light is on that means Diagnostic Trouble Codes (DTCs) have been stored in the computer. Their job is to tell you that one of the car’s systems has a problem and to point to the starting place for diagnosis. If there are codes and you don’t post them, then everyone is blindfolded.

The very first thing I would do is change that original fuel filter. On your car, it’s cheap ($20) and easy. It’s in the engine compartment: http://www.autozone.com/autozone/repairinfo/repairguide/repairGuideContent.jsp?partName=Removal%26Installation&pageId=0900c152801d6652&partId=0900c152801d6652
The spark plugs are probably original, also. They should be examined and, if needed, replaced.
Here is a picture of spark plugs which have seen better days: http://www.autolite.com/pdf/PlugTips.pdf

I would replace the plugs if they haven’t been done and check the throttle body housing for soot and oil buildup, if it is dirty inside clean with spray carb cleaner, a toothbrush and rags, If you get the codes read it may point you to a bad sensor. With your mileage you are probably due for a bad oxygen sensor