chuck99

having problems when starting it wont idle and stalls unless you keep your foot on the gas and then it will clear up. But does not do it all the time. Cleaned throttle body, replaced iacv, and just replaced fuel pump worked fine for two days hard starting today . I am lost and can't figure it out!

Radi

What do you mean by ACV? The idle air control valve in the throttle body? I'd take a hard look at that and the TPS if you are having intermittent idle problems that resolve when you step on the gas.
What brand of fuel pump?

chuck99

Sorry meant idle air control valve, and it was an airtex fuel pump. It acts like a old carb motor with a sticky choke on a cold morning. So you think I should change the TPS, I was thinking that.

F1Addict

I normally don't badmouth brands because I know it's often a matter of personal experience/opinion however, when it comes to Airtex fuel pumps, they are universally reviled. I have never heard anyone say anything good about them, only frustrations over out-of-box failures, loud whining, and unpredictable fuel delivery. I would recommend getting a Bosch.

Before replacing your TPS, search the forum for the testing and adjustment procedure. It's often necessary after cleaning the throttle body because after cleaning the grime from the butterfly it seats differently. At least that's what I recall reading... but it's late so I'd recommend doing a quick search rather than taking my word for it

Kalali

What is the condition of your battery? I would have it ruled out by a doing a load test.

Delta

I was going to post that airtex is honestly garbage they just don't care about quality and might be the source of your problems

SDI-XJ

My 99 is doing the exact same thing. Started doing it in the winter when it got below freezing. It has a newer battery and I started parking it inside at night, didn't have any problems....over the last few months it got worse so i ordered a new IACV....now the problem is worse and it does it on every start...I have a buddy with a scan tool but I wanted to see what info i could find on here. Could someone copy and paste a link to trouble shooting?

Kalali

You may have a faulty Crank Position Sensor. Seems to be a common problem based on the number of related posts here. Do a search and you'll find loads of info on how to test it. And if you decide to replace it, buy it directly from the dealer.

Gee oh Dee

Don't throw any more parts at it. Do some diagnostics like suggested.

Test the TPS. Verify good fuel pressure when its fighting to run like you say. Check for GOOD spark.

It could be quite a few things. Temp sensor, o2 sensor, airtex fuel pump, TPS, etc.

I doubt its a crank sensor, tho, as typically when they go the motor just wont run at times.

SDI-XJ

I took the throttle body off and turned the idle set screw about 3/4 of a turn. The Jeep has about 270k miles on it, maybe the set screw got a little groove in it. started first time with out any gas pedal input....i'll keep you posted...