Fuel delivery issue?

[HeavyMetal]

Odd problem with my 2000 xj

It ran perfectly all the time until randomly today. I turned it off and let it sit for 15 minutes while I was in a store, came out and started it and it would barely run, stumbling, and hammering on the gas didnt rev it up due to it stumbling, i put it in drive and struggled forwards and finally it cleared up and ran perfectly normal maybe after powering forward 30 feet or so.

went to my house, turned it off, came back 15 mins or so later again, same deal...barely any power, stumbling, low idle, forced it forwards on the gas 30-40 feet or so and it cleared itself and revved up and worked perfectly normal, idled fine, so on, drove 40 minutes after no issue, as normal.

No CEL.

What am I looking at here?

[Jeep Creep]

It's the heat that does it. next time youre out and engine is at full temp, shut it off and let it sit for 5-15 minutes. when you start it back up take a look at the engine temp. it probably will be over 210 a good bit. whats happening is, because in 00 and 01 they went to a cast iron manifold and upon shutoff, the fuel in the middle injectors is being vaporized from the heat, causing the shitty running upon start-up. If you let it sit for longer and let it cool down a bit,(about a half hour) it wont do it. Jeep sold a shield that sits on top of the intake manifold and around the middle injectors in order to keep heat off the injectors.

The bad news is that I have that shield on my jeep and it doesnt do shit. I just live with it. it runs like shit for about a minutes tops then cools off and runs fine all day long. My gets a check engine light sometimes from it though for a misfire. Clear the code after and it doesnt come back until the scenario happens again.

[CSaddict]

Put a turbo timer on the electric fan to move air over the motor.

[Jeep Creep]

Put a turbo timer on the electric fan to move air over the motor.

i like that idea

[Bigbike]

Ya its a heat sync issue, I have the same problem with my 99

[Buffalo Phil]

Does your year Jeep have a MAP sensor? That's what my issue was.

[CSaddict]

Caleb when I owned that Jeep it never did that.

[hoggie101]

Vapor lock

[CSaddict]

Will there are some interesting ideas in this thread. I think its all a band aid. The truck didn't do it when it was new. http://naxja.org/forum/showthread.php?t=1031365

[29er]

Could run an aftermarket fan control module for the electric fan. This is the one I had in my Jetta, albeit for a different reason (Germans can't do wiring):
http://www.jegs.com/i/Flex-a-lite/40...FUyY4AodYQcAbQ

I had the model with the radiator probe, not the thread-in sensor, but same idea.

You can set the temperature for the fans to kick on to whatever you want. Takes some trial and error unless you can monitor the coolant temps through the OBD2 port.

Set a bit lower than the stock fan settings, and it will kick on earlier, as well as run a bit after shutoff to cool it down. I also had the manual override switch in mine, so I could run the fan as long as I wanted, regardless of what the sensor was doing.