I was looking on this site and saw a few posts talking about a stumbling problem with the 4.9 engine. I have been having this problem for a while now and want to know how to fix it. I took the vacume line off the egr and pluged the vacume source and the truck runs great now but how do I fix the problem

Thanks in advance
Duane

 

U might have to replace the EGR valve.
Also check for other vacume leaks.

 

dang marines...

 

Duane, you need to build a restrictor plate for the egr valve to downsize the amount of flow it can produce. This will remove the lean misfire. Take the valve off and you will see the gasket between it and the manifold. Use it for a template and reduce the size of the hole to 1/8 in. Use thin stainless. Make 2 holes for the bolts and use a gasket on each side. It did fix mine.

 

I been running it for a few weeks with vaccume line pluged and it runs fine no engine light or any thing. I have the two gaskets on my work bench have not had that mutch time to make the restrictor yet. I am sure glad I found the problem.

Thanks again
Duane