Engine/Transmission (1994 - 1998) Engine Miss

[Jfam]

Recently developed a slight miss which seems to exist only when engine is cold and only at idle (though I cannot be certain of that). Could not find any thread that helped. At 276,000, truck has had a new lift pump and Piers IP. Not enough of a condition to cause any driving problems..... yet. Milage is slightly down.



It disappears when engine is at NOT (normal operating temperature).



Any help appreciated.

 

[hsmith]

Maybe a tired injector. I use a temp gun on the exhaust ports for a quick weak cylinder test.