boatcop1

Well the battery was dead in the Jeep so after it charging for a bit i went to start it up and the idle shot up to 2400 RPM and only came down to about 2100 after warming. If I put it in gear it drops down to about 1400-1500 RPM's. Any ideas on this one?

Merry Christmas everyone.

DFlintstone

I'm not much help, but at least I can bump you up the page! A 97? OBDII maybe...if the battery was really hammered dead, your PCM might need to learn how to walk again, like it had a stroke. When It's reset it takes so many cycles if hot/cold, on/off to reset the paramedics or something. In the meantime make sure you didn't knock off a vacuum line while you where in there. That might do that.

boatcop1

Thanks bud, Yeah it was dead dead dead. I tried jumping it and didn't even get a click or anything! The dome light was barely even lit. So it was beyond dead!

I went out an hour ago and started it and it shot right up to 1800 rpm's and tried to drop to 1500-1600 but stayed at 1800ish for the most part.

Sooooo maybe it's getting better? lol

rrich

The act of charging it probably let a glitch get in the long term memory.
Disconnect the battery for at least 8 hours, it will erase the memory.
There's lots of schemes - turn on lights, cycle the key, kill a sheep at midnight - none really erase the long term memory.

DFlintstone

I don't myself remember reading anything about a long term memory. Not knowing any different I wonder though if you might do well to go ahead and hold the terminals together for a 10 count. If you just NEARLY zeroed out the voltage, it might be starting it's new life with haunting memories of the past. But seriously, a fresh re-boot might be what you want. (I guess there might be other issues if you have a V6)

rrich

Touching the cables together DOES NOT discharge the capacitors that hold the long term memory.

That's internet bull!

Delta

electricaly speaking it isnt to discharge a capasitor touching the ends will work. now does it work with the capacitors in the computer thats yuor opinion

rrich

THEN TRY IT! You'll see it does nothing!

The capacitors inside the computer that retain the keep alive memory are way behind diodes making it impossible to discharge them.

With a scanner that you can get into the computer you can SEE that it does no more than coloring your hair.

Lots of so called "experts" say to touch cables together, cycle the key, turn on the lights, wash the windows, all kinds of goofy things - but they've never tried it - some times I wonder if they've ever even ridden in a Jeep.

The ONLY way - is with a DRB Scanner or disconnecting power for at least 8 hours, 12 is better. Quicker than that only erases the code - if you rip the cover with the title off a book does it erase what's inside?

He said he used a charger on a dead battery - not the only cause - a spark somewhere, even lightening somewhere, a welder, anything that can make an electrical noise can get loaded in accidentally. The computer tries to read the glitch as data - causing all kinds of symptoms. It's not a cure-all, but it's a good FREE place to start.

The real proof - try what the fools say - problem still there? Then do the "deep cleaning" disconnect - problem gone! If that's what the problem was.

boatcop1

man this stinks. tried starting it again with the same results. i just disconnected the battery and will leave it disconnected until tomorow morning when i go back to work. if its still messed up tomorrow after reseting the computer hopefully, then what? am i screwed?

Lesson learned here today, dont charge a battery while its still hooked up to your vehicle

freegdr

how long did it sit b4 noticed dead battery?

freegdr

any thing else done repair wise recently?

boatcop1

Just overnight in the garage. We were using it to hide Christmas presents and my wife left the door open i believe and it just drained the battery overnight. It was completley dead in the morning. Through a charger on it for 2 hours and it cranked right up albeit to 2,000 + rpms!

boatcop1

No it's been fine, last repair was cat back and shocks a few weeks ago.

freegdr

any possible chance you knoced a vacuum line loose/broke therers one gos behind the battery to the vacuum ball ,this can cause a high idle also more air being sucked in the computer thinks you have you foot on the gas pedal

boatcop1

Hmm I'll go check. Going to clean hte IAC while I'm at it.