PonyBoy2000

Car ran rough before so I decided to clean up engine bay to install CAI I purchased a while back. Cleaned MAF, air temp sensor and IAC. Car runs great. But now with the weather changing, I turn heat on, car runs rough. Turn heat off car runs fine again. So what do you guys think it is? Appriciate your diagnosis.


Thanks.

PonyBoy2000

Anyone?

anolis

What exactly do you mean by the car running "rough" maybe a few symptoms of the problem might help

kenv

sounds like a vacuum leak. Mabey under the dash at the heater controls?

dennis_112

If by rough you mean the car has a hard time keeping an idle then sounds like a vaccum leak like kenv said before.

PonyBoy2000

I apologize, yes I ment rough idle. I've taken a look behind control panel and everything looks in place. turned heat on and felt around by hand to feel any leaks, nothing.

Thanks for responce.

99BlackPonyGT

this happened to me in my probe... i know it sounds dumb, but mine was caused by my negative battery cable being loose.... turn the hvac on and the car would missfire everytime the compressor kicked in and my engine light would flash and the gauges would sweep....tightened the cable and all was good...its worth a shot

PonyBoy2000

Checked neg. ground on batt. it's all good. Checked behind HVAC c.p. connections good. As far as leaks, how to check?

RuffCat

I don't think I have ever heard the term HVAC for a term in the auto industry....lol That's for housings or dwellings, but at any rate... I would assume your car is running rough because the car idles lower when any accessoy is turned on. The heat and air conditioning are the 2 main culprits of power consumption. Ac more than heat, however that being said, I would say try a tune-up. How are your plugs? Maybe your idle is just too low? If the negative terminal was loose or corroded you would have charging issues. Also, I would use a volt meter and check the resistance of your COP's (coil on plug) packs. Check them and see what they read in Ohm's. You might find one running a little high. The lower the better. I would just throw some plugs in there while your at it. basic copper NGK TR55 is stock heat range. Gap'em at .055" or go with one step colder NGK TR-6 gap those at .050-.055" They are super cheap and very reliable. Life span is only 15kmi roughly though. Much better than iridium or platinum plugs for consistency and reliability