Rough Idle

[PeteFleck]

Hi there.. I have a 1997 XLT 4.0 OHV.. it was idling rough last year so did the intake manifold gasket which seemed to help, however it is still idling rough/intermittently. What would be peoples best guess as to the culprit?!

 

[rusty ol ranger]

Check engine on? If so start there.

Next step would be plugs/wires/fuel filter

 

[PeteFleck]

No engine light on.. plugs, wires, fuel & air filter done.. problem seems to only exist once truck is warm/has been running a while?