upstatef150

Please help. I have been chasing an issue with my F-150. It has 136,000 miles. It seems to run decent when it is first started. As the truck warms up, it develops rough idle and a skip. As you rev the motor, it smoothes out a bit. Gas mileage has decreased. So far, I have replaced cam sensors, #5 coil, fuel pump driver module. It also seems when it begins to skip, it sounds like there is an exhause leak. It all started a couple weeks back it was running fine, parked the truck, when i started it again, it ran horrible. Now the issue is sporatic. Im not sure where to go next. Im thinking injector issue but it seems it idles better then misses as it is revved. Im at a loss and really would love to get it going again. Thanks in advance for any help.

upstatef150

Also want to add, no noise or knock in the engine. The check engine light has not come on through this until recently. No codes were registering.

grss429

Time to do plugs and new coil boots/springs

upstatef150

Ok. You don't think it's injectors at all? It sounds like a plug issue to you?

grss429

Ive been around 2004-2008 f150s i havent seen many f150 injectors need replacing

upstatef150

Ok thanks. I'll try plugs. You think that may contribute to the very rough idle when warmed up? I'm not thinking cam phasers as I don't hear the clatter like everyone says. I recently had it oil under coated too.

grss429

Yes vey well could be, have they been changed before? If not please read up on them and get the right tools

upstatef150

No I don't think they were. Looks like a break off tool and proper socket are key. I've been looking into it a bit. What did you mean by springs?

grss429

Do the proper soaking as well, and get anti sieze/dielectric grease

Your coil on plug packs have a boot and a spring on them it's always good to replace them as well

Tommy J

Im going to state the obvious. Is it throwing any codes. You changed the #5 coil so Im assuming you have a scanner or had someone else scan it. If you don't have one than go to advance or autozone and have them scan it. What about the fuel filter? Spark plugs, dirty/clogged injectors, air filter, dirty throttle body?. Do as much of this as you can, it won't hurt. If you still have an issue then go from there.