1999 Jeep Cherokee XJ, in my opinion one of the toughest engines in American car history... that being said it has its issues. Recently I drove about 45 minutes on the freeway, got off and stopped at a drive through. The jeep then heated up after sitting in the drive through line so the mechanical fan kicked on. Then I parked and shut off the jeep for about 12 minutes while I ate. When I stated the jeep to leave, it began running really rough, shaking the motor and whole vehicle. I shut it off and tried to start again and the same thing! After popping the hood and looking at it do its thing for a good minute I slammed the hood and it stopped (coincidence?) It then had no further issues. I read it could be "heat bake" where heat from the manifold causes the gas in the 3 injector to boil because of its location and it stopped because eventually fresh cooler fuel flushed it out.

I've had the jeep for 6 years and it hasn't done anything like this before.

While on the subject of fuel injectors, a lot of folks upgrade their injectors from the old 1 port OEM to 4 port injectors, often from the 5.0 mustang for better efficiency. Is this a worth wile upgrade or a waste?

What do you think about the 4.0 inline 6 on the Cherokees, what are the best ways to take care of it?

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ScottyKilmer
ScottyKilmer

Editor

it's a worthwhile upgrade. those 6s are very good engines if you take care of them. Unfortunately the rest of the vehicle is not as well made