I have a small miss in my engine(03 FX4 Screw 5.4L at 245K miles) and am going crazy trying to figure it out. The miss was only around 1K RPM and I could only feel it in nutural while the engine was warming up or if I rev the engine up to the 1K RPM mark. Lately I've noticed it more while driving when the RPM's are low and the engine is under load.

I have recently replaced the spark plugs with new SP479's, replaced the coils with BWD coils, and the fuel injectors with a used but tested good set of CM5081's, a new EV238 PCV valve and none of these made any real difference in the miss.


In an attempt to get some kind of info from the engine I unplugged the #1 coil to force a misfire hoping that the freeze frame data would help figure out where the problem is.

I'm hoping some of the experienced Tech's here can help me out.

So here is what the computer showed.

Fuel sys #1 : CL
Fuel sys #2 : NA
Cal load : 22.4%
ECT F* : 190*
STFT B1 : 3.9
LTFT B1 : 3.9
STFT B2 : -6.3
LTFT B2 : 0.8
RPM : 695
MPH : 0

Please help,
Earnest

 

There's nothing there that is helpful.

Use the scan tool and look at the individual cylinder misfire counts in Mode $06, TID$ 53.

 

My scan tool wont view mode 6 data, it would be very helpful if it would.

Does anyone know of a decent yet cheap scan tool that can view mode 6 data?

 

OK I got a new Bluetooth scan tool so I could see the mode $6 data and it shows misfire counts on cylinder 1, 5, & 7 but the weird thing is all three cylinders show the same exact misfire count which is 81 ea.

Anyone got any ideals?