The truck has 56k miles on it and this is the first problem other than a dead battery. Been great since I got it used last April and have since put about 15k miles on it.

The missing started last week and has progressed pretty quick from pesky to downright annoying. I had a buddy of mine with a snap on scanner try and find a code but he came up empty. It showed him something but he was not able to retrieve it (he's a tranny guy, so I'll cut him a break). After that I bought the most expensive freakin scanner I could find at Autozone (a $279 Actron) and still came up with nothing. No pending codes, no hard codes, nothing. Any idea how long it has to miss before turning on the check engine light?

I got a little desperate today and pulled all the cop's to try and see if I had a bad boot but they all look good and still have plenty of dielectric on them.

Can you say "clueless".

Any and all input is welcome... Thanks...

 

It is probably one of the COPs. They sometimes don't throw a code.
Thread moved to 5.4L Engine forum.

-Matt

 

Does your scanner collect real live data? It should show a misfire in the monitoring if it does. My Diablosport Predator shows live data and will show a misfire even if there is no code thrown.

 

Thanks for the response. The scanner does collect live data, I can watch the fuel trims, o2's, tps, vss, etc... I read the directions pretty good, but I have no idea where I would see that except for watching the rpm's. It misses at idle, and I can see it change the timing and iab duty cycle real quick to bring the r's back up, so I can see the effect of the misfire, but it does not (perhaps I don't know how) let me watch each of the coils fire so I can't see which coil is missing.

What screen are you watching on the Predator to see the misfire?

 

It has a reading that says misfire. It takes several continuous misfires before it will throw a code.

 

Check your misfire count PIDS.

Steve

 

Thanks......

 

Just a follow up... The scan tool (Actron CP9145) I bought will not show anything more than the standard OBDII PID's, so I'm out of luck for now... For anyone who reads this, don't buy that tool to use on an F-250, you will be dissapointed.

Guess i'll just buy a Predator....

 

Call the manufacturer and see if there's anything they can tell you about it.

There should be a way to read misfire counters.

 

krewat- I called them yesterday and verified that their tool was not able to read enhanced OBDII info from my truck. It will just read the standard OBDII generic PID's on my application. Thanks for the input...

 

Crap.

An Autotap (while needing a laptop) can read misfire counters.