Hello all,

I have a 96 XJ Stock everything.
Sometimes it will start and run properly, and sometimes It will not start unless I featehr the gas pedal like a old carb'ed engine with a choke and it will die until the engine is warm.

I Replaced the IAC and still no good. Does the same thing. I cannot Get the scan tool to connect to read Codes..It will just not connect. So I am sort of stuck.

I am thinking some sort of failing sensor or input somewhere, But I wanted to check to see if there are any suggestions on where to start the diagnosis.

Thanks for the help!

Greg

 

Have you tried this method for extracting codes?
https://www.quadratec.com/jeep_knowl...article-24.htm

Also did you clean the throttle body before replacing the IAC?

 

No O did not clean it , nor did I try that method for codes. I will check both out.

Thanks, Greg

 

Although it's important to clean the entire throttle body assembly your problem could be #4 in the link below:
http://cruiser54.com/?p=60

 

Does it otherwise run and drive ok?

 

Yes It runs fine otherwise.
It's getting to the Age and mileage when stock/ Original electrical bits are going to fail on me.... That's why I assumed the IAC and Replaced it. I have since cleaned in there as well but not with a full disassembly / removal and cleaning yet.
I have a Crank Position sensor ready to go, I just have not gotten the thing on the lift to replace it yet.

Original coil Crapped out on me a month ago... Replaced it... Good to go there.

Thanks,

Greg

 

And does it do this on warm starts as well, or only on cold starts?
Sounds intermittent electrical, always a nice challlenge to diagnose.
CPS is possible, (it always is its a sensor well known to fail at some stage. Advise is to get a OEM one, or if not possible find a reliable brand.

In the meantime some other simple and free stuff first:
-Adjust the throttle cable, just to get a good baseline ( instructions on this easy to find via a search)
-Clean the throttle body out as best as you can, especially the valve on both sides and where it sits (so the walls of the throttle body ) (its best done with TB removed, but you'll need a new gasket for reinstalment)
- Test your TPS (do a search for the procedure),it requires a multimeter and its easiest with an analogue multimeter to see the meter sweep better)

As always, clean all grounds up, which in electrical trouble shouting is always a good practise and takes things out of the equation.

 

Thanks for the tips. Runs fine warm.. just was erratic on cold starts.

Greg

 

Well I think I have it sorted.

Checked all Codes with key on / off sequence - Nothing of note. - It seems that my '96XJ has an OBD port, however my code scanner will not connect to the vehicle.

Cleaned battery and alternator connections and grounds real good.

That seemed to solve it.
No measurable voltage drop and it starts and idles fine now every time!

Thanks all and Happy Jeepin'

Greg

 

Good to hear it worked and thanks for getting back.
Simple cleaning and checks, especially grounds.