Replaced exhaust manifold, when started revs to max rpm -
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post #1 of 4 Old 11-20-2010, 01:08 AM Thread Starter
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1998 TJ Wrangler 
Join Date: Nov 2010
Location: Ewa Beach
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Replaced exhaust manifold, when started revs to max rpm

I replaced my exhaust manifold. After putting everything back, when I went to start it the engines rpms rev extremely high and will keep going if I let it.
I have checked for vacuum leaks there were none, replaced IAC and MAP sensor, which didn't make a difference. I have read over other threads with similar problems, but they only had responses involving vacuum leaks.
And now I am running out of ideas.

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post #2 of 4 Old 11-20-2010, 01:19 AM
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1998 XJ Cherokee 
Join Date: Jul 2008
Location: pittsburgh
Posts: 291
you have an intake leak somewhere. most likely you dont have the intake sealed against the head properly. which is a vacuum leak. double check to see if your sealed against the head or see if you possibly cracked the manifold when installing it. i changed my exhaust manifold and i had a tough time getting the manifold back on the dowel pins. pull the intake off again get a file and LIGHTLY scuff out the dowel holes on the manifold. basically pull the manifold off and double check everything you did that should reveal the issue causing the WOT condition.

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post #3 of 4 Old 11-21-2010, 07:26 PM
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1976 CJ7 
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Location: minnesota
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same thing happend to a friend when he rebuilt his engine. the dowel pins didnt seat all the way. he said the power steering pump was hard to line up with the intake not seated on the head.
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post #4 of 4 Old 11-21-2010, 09:52 PM
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2000 TJ Wrangler 
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Location: Baltimore
Posts: 1,018
vaccume leak between the intake manifold and the cylinder head. spray some throttle body cleaner around the area of the gasket and if you have a leak the engine will suck in the vapor and engine speed will increase at a noticeable rate. try touquing down your intake manifold bolts again.

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idle issue , idle problems , idle too high , idles rough

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