Rough idle problem.

[mlcase27]

I have a 94 ford explorer with 197,000 miles on her. Every once in a while when I start her she stumbles and idles real rough until I start going, in drive or reverse and after hitting the gas. If I just stay parked and rev the engine it won't stop, but as soon as I start going it goes away. What could be causing this? It has been going on for a while and I have cleaned the MAF sensor but she still does it. ANY suggestions???

 

[greco37]

i would try checking for vacuum leaks, cleaning the egr valve, replacing plugs and wires, cleaning injectors, in that order

 

[mlcase27]

Thanx! Is there a diagram that you could show me that tells were the EGR valve is and how exactly to clean it? Thank you

 

[greco37]

search this site for the diagram I dont know where it is on your truck. The egr valve is like a plunger that moves by vacuuum when commanded and can get stuck open or closed. It is mounted directly to the intake manifold. You should be able to look through its outer shell and see the rubber diaphram inside. You should also check its vacuum lines. When the plunger moves so does the diaphram. Have someone rev the engine while you look to see any movement in the diaphram. If it doesnt move or you cant see it you will have to remove it and see if the plunger is sticking and then clean it and put it back.