Jump to content

wierd idle/hesitation

Recommended Posts

so mytruck is a 87 mj 4.0 2x4 and it has just recently started to get a rough idle and feels like hesitation when starting to drive. this only seems to happen once the truck is hot. and its not a over heating hot just normal operating temperature. if i really get down on the gas while its doing this it seems to sputter at first and then will accelerate like nothing is wrong and while driving it seems fine but as soon as i hit a light or park the rough idle returns and the hesitation when i go again. if i park the truck for a while and it cools down the problem is gone untill it warms up :dunno: now iv done some lookin around and looks like i might need to do a valve cover gasket but other than that everything looks fine. a valve cover gasket wouldnt do this would it? any ideas?

Link to comment
Share on other sites

If you can, do a fuel pressure check on it, it sounds like after it hits operating temperature it lacking fuel feed, almost like a vapor lock.


Here's the test and spect's on the fuel pressure -


http://www.lunghd.com/Tech_Articles/Fue ... ostics.htm


Another thought.........


http://www.lunghd.com/Tech_Articles/Eng ... ostics.htm


The valve cover leaking should not have anything to do with a vacuum leak, or rough idle.

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

  • Create New...