jimd4x4

I have a 99 JGC with a 4.7 engine. When cold it will start than die. If you feather the accelarator a little. It will idle than let it warm. Once warm there is no problem. I have replaced the IAC it is better. The new IAC was shorter I figured that once driven the computer would adjust. It has not had a good drive since install. Any ideas gentlemen.

Thanks Jim

ol"blue

Sounds like a problem with the IAT (Intake Air Temperature) sensor to me. On the 4.7L V8 it is mounted on the left (drivers) side rear of the intake manifold, to the rear of the throttle body. You need to test the resistance of it to verify if it is good or bad. There's a chart for this in the manual.
Dan

jimd4x4

Thanks Blue I will check it out.

ol"blue

No problem. Hope it helps.
Dan

jimd4x4

The intake air temp sensor did not fix the problem. Should I disconnect the battery to reset the computer? Does it need to be driven for awhile to relearn? I did notice that the IAC was a different length but figured it would adjust.

ol"blue

I'm not certain, but it couldn't hurt. Remove the positive cable from the battery and hold it to the negative cable for 10 seconds. That will drain the charge from the capacitors, then it needs to be driven to relearn the parameters.

jimd4x4

Alright gentlemen here we go an update. I had a long and fruitless weekend. Here is what I did. I replaced the TPS and sparkplugs. Still have same issue. I also took the old number off the IAC and crossed it to same IAC I was using. So I took it back to the store and had replaced. After this with positive cabled disconnected. I used a jumper from positive cable to negative cable still connected to battery for 10 seconds. The Jeep started and sounded much better. I took it for a 30 minute test drive for computer to relearn the parameters. Later Sunday afternoon same symptoms. Which are when vehicle is cool you have to feather the accelarator pedal to start and idle. I have not replaced the fuel filter that will be tonight. Anybody else want to weigh in on this. I has become personal now.

crc

Same thing was happening with my 99 XJ last year. It had the original battery. I replaced it and problem solved.

jimd4x4

crc, wins With crc's reply in mind I decided to charge the battery. I put my charger on and it was drawing lots of amps. I waited an hour and it started and idled perfectly. So I put a trickle charge on overnight. Next morning started and ran great. Couple of days later it was back to the same old crap. Pulled the battery and took it to the local parts store. Thay put a test on it and it was bad. I replaced the battery and everything has been fine. There was no indication that the battery was failing. Who would of thunk!!!!! Hope this helps other Jeep owners.

ol"blue

Well I'm glad you've got her straightened out.