So, I was driving around today and the jeep was doing great. Its 115 here in Vegas and the jeep never got over 210.

I stopped for about 20 minutes and went outside to leave. I started the jeep and it died almost instantly. I started it again, and again and again... all times it died within seconds.

I finally pumped the gas quite a bit when I started it to keep the RPM's up and it backfired a time or two, I took off still pumping the gas and it kind of caught and went back to normal.

I got home, turned it off and started it a few times, no issues.

What the hell happened?!?!

FIY 1999 jeep cherokee 4.0l auto with 108k

 

Sounds like heat soak / gas in the fuel rail vaporized.
When you turn off the engine, heat from the block vaporizes the fuel in the fuel rail. So its similar to vapor lock issues. Once liquid fuel makes it through the fuel rail to the injectors everything is back to normal operation. You can insulate the injectors to help prevent this happening again. No guarantee but you can wrap foil on injectors. I think there are actually covers made for the injectors. Hood vents help also.

 

You need to verify what the actual temp is on her. 210deg is normal operating temp for the 4.0. You need to get a temp heat gun and point it at the t-stat housing to get a true temp reading to see if your gauge is not reading to low and you are actually over heating.

 

I'm more of a "kindergarten physicist" , than a Jeep pro. Amongst the "answers", a sleeve that slips over the injectors to provide shielding from radiant heat sounds like an idea. There is a TSB deal right by "search" that might have more on the heat getting to the injectors there.

There might be miss-fire codes set for the cyl's near the middle.

I meant "TSB" (it says "TSB & recalls"). Good luck!

 

The temp gauge is right, I was having overheating issues and replaced everything. New 3 core radiator, hensco high flow water pump, high flow thermostat and high flow thermo housing. I also installed 2 large hood vents.

Heat soak makes sense. Anyone know where to buy the foil shield that comes on manifolds stock, mine didn't have that? Also, I think my header is cracked and I was going to do with the aftermarket one, maybe I'll wrap it as well to help out. Need all the help we can get with heat out here

Thanks for your help guys, butt pucker moment stuck in the desert on a 115 degree day with a non starting cherokee lol