Jeep cranks up, but with high rpms, it idles semi-rough, almost sounds as if it is misfiring while driving down the road, it cuts off when put into reverse, and also revs up when put into reverse before it cuts off, when I re-crank it, the jeep sputters and spits pretty rough when started back. I have replaced the idle air control valve and cleaned all sensors. It has a brand new map sensor on it, I just don't know what else to do... vacuum leak? a different sensor? transmission? I NEED HELP FAST!!!!

SOURCE: idles fine but stalls when i give it gas?

Hi jkeefer,

I'd suggest you check the air flow sensor

Regards Johngee10

SOURCE: PO171 OBD-II Trouble Code " System Lean To Bank 1

Check PCV valve and be sure it is not stuck open.  Check for vacuum leak at intake manifold.  

SOURCE: jeep starts and idles perfect no acceleration,

Sounds like the catalytic converter or muffler are clogged. There isn't much exhaust at idle, but when you accelerate your exhaust volume increases, thus if your catalytic converter or muffler are clogged the restrict the exhaust escaping out thus causing an excess of back pressure which won't allow the engine to breathe normally.

ray calhoun

• 166 Answers
• Posted on Jul 20, 2009

SOURCE: 96 jeep cherokee idles high/accelerates by itself

try unhooking the cruse cable

SOURCE: 1998 Jeep grand Cheroke hard cranking, sputtering, rough idling

In READING what you wrote, it appears that your car is difficult to start and pretty much is rough while running....It also appears that your are randomly replacing parts...How did you verify that the parts your have replaced had failed? I suggest you get a basic manual like chiltons or haynes as well as a decent digital volt/ohmeter, then do some testing. Pay close attention to map sensor test and manifold air temp. Having a good fuel pump does not insure that your injectors are clean enough to deliver a good spray pattern This will not show up on any test...you need to actually look at them. There are other items to look at but I think you will likely find your problem in what i mentioned. (you already checked for vacuum leaks, right?)
Good luck!