87 xj idle wayyy to high?

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06-18-2010, 11:00 AM

mikeg216

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Model: Cherokee

87 xj idle wayyy to high?

so i did a tune up and adjusted the idle down but now its over 2k and my exhaust manifold is running red hot, i have no ideas as to whats going on can anybody point me in the right direction

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06-18-2010, 11:02 AM

superj

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Year: 1999

Model: Cherokee (XJ)

Engine: 4.0 I6

vacuum leak. the red exhaust is from a lean mixture and the idle being up is from the air causing the lean mixture

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06-18-2010, 11:06 AM

RENIXBEAST

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Year: 1989

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Engine: 4.0 I6

My first guess would be the I.A.C. located on the throttle body. Probly NFG, unplug it and see if anything changes.

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06-18-2010, 11:15 AM

mikeg216

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thanks guys gonna go check it out

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06-18-2010, 01:03 PM

alpine.adrenaline

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Year: 1999 XJ

Model: Cherokee

Engine: I6 4.0L

Quote:

Originally Posted by superj

vacuum leak. the red exhaust is from a lean mixture and the idle being up is from the air causing the lean mixture

X2, you have air entering somewhere, probably between your intake manifold and cylinder head. Use an unlit propane torch to find it, your engine will run different when it sucks in the propane.