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I just replaced pistons, lifters, pushrods, and head on a 1999 Jeep Grand Cherokee. It started right up, but the RPM went to redline.
I checked throttle body components, the linkages are OK, but the valve plate is not opening.
What can cause this?
It sounds as if the intake manifold is not sealed properly. The large intake leak will force the engine to redline instantly once started.
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