Engine reves to the max at start up
02-23-2010, 11:58 PM
#1
Newbie
Thread Starter
Join Date: Feb 2010
Location: Seattle
Posts: 4
Likes: 0
Received 0 Likes
on
0 Posts
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! 
02-24-2010, 12:11 AM
#2
Senior Member
Join Date: Jul 2008
Location: Reno, NV
Posts: 803
Likes: 0
Received 0 Likes
on
0 Posts
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!
02-24-2010, 12:15 AM
#3
Member
Join Date: Nov 2009
Posts: 189
Likes: 0
Received 3 Likes
on
3 Posts
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..
02-24-2010, 12:22 AM
#4
Newbie
Thread Starter
Join Date: Feb 2010
Location: Seattle
Posts: 4
Likes: 0
Received 0 Likes
on
0 Posts
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!
02-24-2010, 12:46 AM
#5
Senior Member
Join Date: Jul 2008
Location: Reno, NV
Posts: 803
Likes: 0
Received 0 Likes
on
0 Posts
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!
02-24-2010, 12:50 AM
#6
Member
Join Date: Nov 2009
Location: Edmonton, Alberta, Canada
Posts: 133
Likes: 0
Received 0 Likes
on
0 Posts
Model: Cherokee
I would also say that you have a major vacuum leak. possible that something happened to the gasket when you installed the intake and exhaust manifolds?
Trending Topics
03-15-2010, 09:01 AM
#12
Newbie
Join Date: Mar 2010
Location: flordia
Posts: 26
Likes: 0
Received 0 Likes
on
0 Posts
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!
03-15-2010, 09:51 AM
#14
CF Veteran
Join Date: Mar 2009
Location: Watha,NC
Posts: 1,208
Likes: 0
Received 1 Like
on
1 Post
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.
