My 4.2 is missing out when accelerating and when climbing inclines. I've changed the plugs and it quit for a while, changed the wires and it quit for a while. Took it to a garage, they said the computer showed the coil and replaced it (for a nice price) and it worked for a while. It was recommended to replace the Oxygen sensors and I did that. Replaced the fuel filter. All of this and it still has the same problem. Any suggestions?

 

did you notice a slight drop in the coolant level? if so you have the same problem i had which is the lower intake gasket failing.

 

Thanks. I had been noticing a coolant level drop but didn't think of relating the problem I'm having with it missing out. I flushed the system, added new coolant and some Bars-Leak thinking I had a small leak somewhere. Maybe this will this fix the problem with the gasket. It hasn't yet. What did replacement of the lower intake gasket entail? Were you able to do it yourself?

 

I strongly suggest you stop by the 4.2 forum and do some investigating. You'll find info on the leaking gaskets problem.
I'd guess your's is an early '98 or prior and you have about 100,000 miles.
See you in the 4.2 forum.

 

i also added stop leak but used the aluma seal which helped but if the gasket isnt changed they say it could hydro lock and do severe damage to the rods. It was fairly easy to do just time consuming i removed all the upper intake and coil pack there are lots of intake bolts on upper and lower the hardest are the rear lower intake bolts you need to disconnect the 2 vaccume actuators at the rear of the lower intake and remove them to access the rear lower intake bolts take care not to damage the plastic keepers that attach the actuator rods to the intake in the rear the are very brittle depending on the use i pryded them loose with a flat screw driver when istalling the new gaskets dont use any sealer they interlock at the lower intake and sides install the lower side gaskets first then the front and rear setting the intake straight down on them as they are very delicate gaskets were costly and not available had to order them at advanced auto around $79 for upper and lower gasket then all intake bolts are torqued in in/lbs in 2 stages each for upper and lower dont recall the torq specs any local ford garage will give them to you. the results were amazing i had been driving it that way apparently for a couple of years because i had no skip and lots more power even starting was easier. good luck and take your time the results will be worth it

 

www.leakingfords.com

 

Thanks to all. Looks like I'll be replacing this gasket before it's too late.