Engine reves to the max at start up
Thread Starter
Newbie
Joined: Feb 2010
Posts: 4
Likes: 0
From: Seattle
Year: 1999
Model: Cherokee
Engine: 4.0
Engine reves to the max at start up
I just replace my cracked exhaust manifold tonight( typical of the 4.0) on my 1999 Cherokee sport and never had a problem until now, everything when smoothly till I fired it up and it went to max rpm.....its like its being floored! I can't imagine what this problem could possibly be. It does it every time I start it up! AH! Any ideas would greatly be appreciated! 
Senior Member
Joined: Jul 2008
Posts: 803
Likes: 0
From: Reno, NV
Year: 98
Model: Cherokee
Engine: 4L
I just replace my cracked exhaust manifold tonight( typical of the 4.0) on my 1999 Cherokee sport and never had a problem until now, everything when smoothly till I fired it up and it went to max rpm.....its like its being floored! I can't imagine what this problem could possibly be. It does it every time I start it up! AH! Any ideas would greatly be appreciated!
Member
Joined: Nov 2009
Posts: 189
Likes: 3
Year: 2000
Model: Cherokee
Engine: 4.0 I6
maybe you have a bure on your throttle cable.. check EVERYTHING over.. could be a LOT of things.. I always check 3-4 times when finishing a project or install for corrections or possible mistakes i have maid..
Thread Starter
Newbie
Joined: Feb 2010
Posts: 4
Likes: 0
From: Seattle
Year: 1999
Model: Cherokee
Engine: 4.0
Its so weird! nothing is stuck at the throttle. The butterfly valve doesn't even open, but yet it still revs out to the red line.....Vacuum leak possibly, maybe I messed up the fuel injectors, I did put a little brake cleaner on them to clean them up. Could that be it? Thanks again!
Senior Member
Joined: Jul 2008
Posts: 803
Likes: 0
From: Reno, NV
Year: 98
Model: Cherokee
Engine: 4L
Its so weird! nothing is stuck at the throttle. The butterfly valve doesn't even open, but yet it still revs out to the red line.....Vacuum leak possibly, maybe I messed up the fuel injectors, I did put a little brake cleaner on them to clean them up. Could that be it? Thanks again!
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Newbie
Joined: Mar 2010
Posts: 26
Likes: 0
From: flordia
Year: 1988
Model: Cherokee
Engine: 4.0
I just replace my cracked exhaust manifold tonight( typical of the 4.0) on my 1999 Cherokee sport and never had a problem until now, everything when smoothly till I fired it up and it went to max rpm.....its like its being floored! I can't imagine what this problem could possibly be. It does it every time I start it up! AH! Any ideas would greatly be appreciated!
CF Veteran
Joined: Mar 2009
Posts: 1,208
Likes: 1
From: Watha,NC
Year: Jeepless at the moment
Take some of that brake clean and spray along the intake manifold while running itll bog down when it sucks it into where ever the leak is....did you remove the injectors?... if so you may have a pinched oring.
