00 XJ will not start

First of all I did a search and did not find anything specific to what is going on with my Jeep. A few weeks ago I went to start my jeep and it would turn over but not start. So I held the gas pedal to the floor and it fired up, but it would only stay running if I was giving it gas. It would not idle at all. So I started driving. I would shift into neutral at stop signs, and rev it up to keep it running and then drop it into drive. I drove it for about 10 minutes and it finally started to idle on its own. After that it was fine. It would start up and idle and no other problems were noted. That was until last night. It did the same thing. I could keep it running by giving it the gas, but as soon as I let my foot off the gas it would die. So I drove it (I had to make it home) and about 5 minutes into driving it I came to a stop sign and it finally would idle on its own. Today all is fine.... What is up? It is the TPS?


Thanks in advance and I apologize if I started a duplicate thread.

either the TPS or the IAC(idel air control), its more likely that the IAC is sticking and blocking air at idle.

I have this same problem, what is the answer? Could it be a MAP sensor? I have a 1997. I would appreciate a super quick response because I am trying to get it fixed right now and need it to get to work!!

Well, I don't have this problem on my XJ, but had the exact same problem with my previous car...1991 Escort GT...it was the IAC valve/solenoid. It wasn't allowing enough air to pass to the intake to keep the vehicle at idle at first startup when it was cold. It was just a matter of cleaning the IAC and the intake passages.

After the car warms up, it doesn't need the IAC anymore except when the AC is turned on...to increase idle.

I can hear the motor sucking tons of air in..more than usual. Could it still be the IAC? It was running fine, then wouldnt start without the pedal to the floor, and then ran fine. Started right up later, and then made it about a block, and then it stuttered and died, then it wouldnt stay running without revving it up to about 2-3k.???

i had a simular problem in my old 87 xj, turned out to be bad gas. It took about 6 bottles of heat to fix it.

chelms27 said:

I can hear the motor sucking tons of air in..more than usual. Could it still be the IAC? It was running fine, then wouldnt start without the pedal to the floor, and then ran fine. Started right up later, and then made it about a block, and then it stuttered and died, then it wouldnt stay running without revving it up to about 2-3k.???

Click to expand...

So, the problem persist even after it has warmed up? If so, it seems less likely that the IAC would cause that...but it would not hurt to check.

Once you get is idling on its own...does the rpms go slightly up when you turn on the AC? If so, then your IAC might be okay.

One other thing to check...look at your throttle body...may it just needs a good cleaning. If there is gunk around the butterfly and passages...it might be the cause of your problem.

The following is from another forum...the basics still apply...

"Does your idle rise and fall over and over again? Does your 'Stang stall when you come to a stop, or even when you put it in gear? Well if so then this series of articles if for you.
In this age of fuel injection, idle problems can literally be caused by hundreds of different things. What this series of articles is aimed at is how to fix the most common idle problems found in the Mustang.
The fuel injected Mustang uses a small motor/valve assembly that allows a specific amount of air to enter the engine to control it's idle. This valve is comonly called the idle motor, the IAC (idle air control) or the IAB (Idle air bypass). When your car is new the IAC works remarkably well. The problem arises when the car gets some miles on it (usually 75K+) and carbon fouling takes its toll.
What happens is dirt, excess air filter oil, and most notably carbon gunks up the IAC valve and doesn't allow it to either open or close properly. This can cause an really high idle, a lumpy/surging idle or no idle at all. The solution is to either replace or clean the IAC. "

TB is clean, It wont stay running on its own long enough to warm it up, it spits and sputters out black smoke, and then RPM's drop and it dies. And like I said before, it will not even think about starting unless I florr it.

Sorry...yeah, that sounds like a more serious problem that just the IAC sticking.

Almost sounds like a timing problem...but everything is electronic on the 97-01 XJs.

Well, hopefully, someone here can give you some suggestions...I'll ask around here as well...

good luck.

the Throttle Body can be completely clean but the IAC and TPS can still be completely gummed up. Decarbonize your TB but thoroughly clean the IAC and TPS using toothbrush and carb cleaner. Mine used to hesitate before doing this and runs better. You could also be sending too much cold air to the engine and the ECU isn't able to adjust

Ok, I started it up again(pedal to the floor). It revved up to about 2500, and then the rpms fell back down slowly. I kept it running by just touching the gas and the rpms would always jump up to 1500, and then slowly go back down. Eventually it started idling on its own around 1100. This whole time the temp guage didnt move from cold??? Then I touched the gas again, and the rpms jumped back up to 2500 a few more times, and then all of the sudden the temp guage went up to nomal(210) and now it is running fine again? What the Fuc$ to do now so this doesnt persist?

o2 Sensor. I just had the same problem with my 2000. I had to replace all 4 o2 sensors as well. Take it to autozone and have them put the code reader on it. It is free.