I have a 97 F-150 with a 4.2 v6. When I am at highway speeds it seems like I have a miss or hesitation. Its like the engine is sputtering. I changed the plugs and the fuel filter. What else should I try?Thanks for your help..
G_MAN

 

[updated:LAST EDITED ON 30-Aug-02 AT 00:50 AM (EST)]Check to make sure that the coil pack is firing on all cylinders. The one on my Windstar 3.8 quit firing #2 even though it fired 2&6 together. Could be going out. Just a suggestion.

P.S., the 4.2 is an oversized 3.8. old design, just added a few cubic inches.

 

 

Test for clogged EGR ports by appling vaccum to the EGR valve while engine is idling. If the ports are clogged it will begin to miss regularly b/c all the EGR gas is going to one cyl. If they are not clogged it should die or almost die. To get to the ports the upper intake has to come off. Blow them out with compressed air. They look like circles at the top of the rectangular runners in the lower manifold. This is a common problem with 4.2s. Good luck.