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jimd4x4 03-09-2010 03:28 PM

Trouble Starting 99 4.7
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. I have alos replaced the Intake Air Temp Sensor. Still no change I will disconnect the battery. Let it relearn the codes and try again. In another forum they mentioned disconnecting positive cable and touching to negative for 10 seconds. Anyone Thanks

Problem solved:
crc, wins (Different Forum) 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.

robpp 03-09-2010 03:43 PM

Re: Trouble Starting 99 4.7
they suggest touchijng the cables as it drains the capacitor so all memory is realeased, things like radio presets, etc.

on the WK i was taught to either step on brake or turn on lights after diosconnecting the negative to make sure the memory is drained.

what about the TB and injectors. see what the intake part of the Throttle body looks like, could use a cleaning. and what about injectors. im a big believer in BG44K at least once a year to keep injectors and intake tract clean.

jimd4x4 03-09-2010 06:34 PM

Re: Trouble Starting 99 4.7
When I did the IAC. I cleaned the throttle body with Seafoam Deep Creep. I will do the BG44K they carry local. I seen a lot of post about battery being bad. The post are clean I also did that with the IAC. Did not like the feel of negative cable. It tightened up but I have had better.

jpvette 03-11-2010 08:27 PM

Re: Trouble Starting 99 4.7

Originally Posted by jimd4x4 (Post 166246)
I have replaced the IAC it is better. The new IAC was shorter I figured that once driven the computer would adjust.

Sounds like you have purchased an IAC for the H/O 4.7 wrong length. The initial diagnosis is correct however, you just need the right part. :)

jimd4x4 03-16-2010 03:03 PM

Re: Trouble Starting 99 4.7
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.:slapfight::lol:

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