poppajeep

'95 XJ 4.0 liter. start it up first thing in the morning, runs great. It'll run great for as long as I want. Shut it off to go into a store. Start it up after returning to rig, and it runs rougher than a "loaded up" engine for about 30-45 seconds, then it clears up and runs fine. I've been getting rotten gas mileage for some time, possibly the same cause for both? First time it did it, I replaced the fuel pressure regulator, and that cured it for some time. Next time it happened, I instinctly replaced the regulator again, but it still happens. Any ideas? Thanks

xjbones

injectors might be leaking into the cyliders when you shut it off.

might be the cause of your bad gas milage too. if they are leaking after shut off, they prob arent spraying right.

Abovetimberline

Another thing it could be is the iac,take it off and clean it and the passage on the throttle body.

DEVILSTOY

mine has been doing this for ever and i just fixed it today, i swore my injectors were leaking , soo heres my story lol well after replacing lots of things here and there i finally got down to what it was i pretty much narrowed it down to a fuel issue, to start i upgraded my injectors to the mustang 19# seemed to be idleing smoother but the popping got worse , i couldnt even drive the thing now , i had a fuel pump here just waiting to go in but i wanted to make sure my injectors werent the cause first , so i swapped my pump out and since mine is a 97 the pump , fuel pressure reg and filter are in tank connected together i cant be certain exactly what was bad but my god it feels like a whole new jeep right now , i really hope im done chaseing this problem down