blacknight

Lastweek the car took 3 times to start. The 1st time it was likethe battery was dead but the interior lights worked. Today when I started the car the idle dropped to 300 and wanted to stall and when I backed it out the garage it would want to almost stall everytime I gave any gas. It would idle at 300-400 rpm's. Then after a 30 min drive today was at a signal and the car started to idle rough because the idle dropped down to 500 rpm. What coudl be going on?

tylerdurden

Do you have the factory battery still? Check the postive cable for acid corrosion.

robb4964

Well mine took spells doing that , come to find out it had a hole In a vacume line " size of a nickel " took me 2 minutes ot plug , and runs like a different car.......

DanBUCF

Sounds like something is wrong w/your battery connection. Everytime the battery is unplugged from the car for a little while, the computer will reset itself. It has to re-learn and calibrate itself with all the air/fuel ratios and lots of other stuff. Just let the car do its thing for a couple of minutes before driving it and it will be just fine. Probably a corroted terminal or something....I would check that.

chpmnsws6

usually with a nice sized intake leak it will idle at 3k for a few seconds then drop to 400 or so rpm and act like 2 plugs are dead..... scared the hell outta me the first time

robb4964

thats what Mine was doin ...

KAO 91

My battery was disconnected for about a week and half. After re-connecting it and starting it up, the car was idling very low and fluctuated below 1,000 RPM. How long would it take for the computer to re-calibrate? I believe the previous owner had the car calibrated after installing SLP MAF, LID, smooth bellows, exhaust, etc. Have I un-done the custom calibration?

Note: The engine sounded fine when I reved it up, but fluctuated again once returning to idle.

Thanks for any replies!

Klypto

tune should still be there, but there rly isnt a need to tune a car with just that done anyway

robb4964

HOLY COW! Talk about bringing a post back from the dead. Check the dates fella's. this post is 3 years old.

KAO 91

I'm a fan of the search button.

Back to my problem; could the cause be related to a bad battery connection and/or the computer re-setting itself? Does that sound reasonable? How long would it take without power to nullify a tune?

Thanks for any replies!

AL SS590 M6

Most any time that the power is pulled from the PCM the computer has to relearn the idle. The best way to do this is to start it up and let it just sit and idle for ten minutes then turn the air conditioning on to max and let it idle for another ten minutes. It should straighten right out.
You may have to start out by resetting the PCM again. You can do this by turning the key to run without starting the motor. Go under the hood and pull the PCM "batt" and PCM "ign" fuses. Leave them out for about 10 minutes. Reach in and turn the key off and reinstall the fuses. PCM is reset.

And to ease your worries any tune modification is flashed to an area of the PCM that does NOT reset with power loss. It would have to be reflashed to change anything.

KAO 91

Thank you very much for this reply -- I'll give it a try soon!