Rpm actin Weird ...

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07-22-2012, 08:12 AM

simond

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Year: 98

Model: Cherokee

Engine: 4 L

Rpm actin Weird ...

Xj 98 4l auto trans ... SOmetime ... on Drive, everityng goes well ...but if i put it on Neutral or park ..it goes up at 1400 rpm ...without any warning... i'll be able to shift back in D but...1400 to 700 RPM ...it give a little kick ...

someone know where to look or already happen ?

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07-22-2012, 08:14 AM

UsmclovesXJ

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Year: 1993

Model: Cherokee

Engine: I6 4.0L HO

Quote:

Originally Posted by simond

Vacuum leak

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07-22-2012, 08:16 AM

UsmclovesXJ

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Year: 1993

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Run threw all of your vacuum hoses to check and see if there are any disconnected hoses or cracks in them

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07-22-2012, 08:25 AM

RenegadeT

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Model: Cherokee

Engine: 4.0L HO

yep. spray some brake parts cleaner on all the vacuum fittings, intake manifold flanfe, injector O-ring ports. The RPMs will change when the BPC gets sucked in. Also wiggle the MAP sensor line, see if you can get that to seal better. A stuck IAC sensor (rear of the TB) can cause that too.