If you are coasting just lightley put pressure on the gas. Thats how I was able to recreate the intermediate missfire... It was due to a bad coil. I think the service manual has something there about checking the coils. Also I would say replace one coil at a time and then take the truck for a drive to see which coil is bad that way you dont have to replace all of them.

 

take out the new spark plug and take a check. then me i would check the oil or radiator fluid... see if u see anything.. not trying to scare ya but i got the same thing happening to me and found out both head gaskets blew but thats worst case. deff check ur tire pressure as it is getting cold out and ur pressure will go down. clean ur CAI and like he said could be the blended fuel. i know last nite i burnt a hole quarter and half and only drove 40 something miles...

 

Thanks guys!!! Lots O' great ideas. Plugs are all clean, nice and light tan. Coil is new on that cylinder, and the miss only occurs at idle. Already seafoamed it and smoked out all of northern NJ! It definitely made an improvement! I will say that. 102K miles on it at the moment. All fluids are fine.

Ball joints, tie rods, alignment, etc all new or recently checked

I suspect that its some metering/measurement problem, like O2 sensors misreading, etc. Not sure the misfire has anything to do with the lousy mileage, but they could be related.

Gonna go put my OBD reader on it again and do the **** probe on it

 

An O2 will cause a problem at idle that will disappear as the engine RPMs increase. You will notice lousy gas mileage as well, since normally when an O2 fails it will richen up your mixture.

However, I would guess your O2 is not the culprit; you would be getting a code for multiple cylinder misfire or a code for bank 1 cylinders running rich from the O2 circuit reading high.

 

may try swaping the injector out with another cylinder, and see if the miss moves to that cylinder, the o2 sensors are another good idea

 

yeah not looking forward to all this replacement stuff! lol

 

i know that beating the snot out of my truck has put a toll on the engine, but at 100000 miles it still pulls strong and does get over 20 miles to the gallon on the highway. as far as gas consumption, i would bet its an injector, when i put the nitrous system on the truck, i had to switch mine out to a ford injector, yes ford. the spray out of the injector was better than the mopar one, if your injector is clogged or going bad, it will drip gas like a leaky faucet instead of having a nice spray, and if its the same cylinder that having the miss, just swap it out, they are not that exspensive

 

nice!

 

That's a great suggestion!! I've been following the ignition path, and mostly ending up nowhere. The fuel system was my next stop on the magical mystery tour....

 

I got 15.5-16 with my V6 (+parttime 4x4), and i am getin about 14 city and about 15.5-16 Highway with my v8 (+full-time 4x4) that bein said, with the v8 i was hitin the gas pedal hard on the first leg of my road trip, and the second leg i had about 35 mph winds. I have a buddy with a 4x2 flex-fuel V8 that gets about 16 in town and 18-19 on the highway.
(sorry i aint tryin to hi-jack the thread)

Do you have a part # for those ford injectors? Would it be better to get the injectors like Blown287 has to have on his truck with a super, or is it better for those with out a super/turbo just to stay stock? And Finally How hard is it to change injectors out?
(again i apologize, I aint intending to hi-jack the thread)