2001dodge ram misfire on 1


#1

I have a misfire on 1 I recently changed intake and plenum gasket, changed plug, wire, injector, cap, rotor, compression check and pulled valve cover rockers moving good and I recently swapped injector wires on 1&3 only shows misfire on 1 anyone have ideas help please


#2

This is 5.9 gas


#3

What was the compression number?


#4

100-105


#5

Not sure Gage 100% accurate other cylinders about same


#6

You have a problem if that number is accurate. Good numbers even on a worn engine should be in the 175 or better range. The general rule of thumb on compression is 20 X the compression ratio. There will be variances based on altitude and barometric pressure, engine wear, and so on.

If you revisit the compression issue you should do a wet test. This means a small squirt of oil into each cylinder before it’s retested. If the number takes a substantial jump upwards there’s a ring problem. If the number remains the same or only increases slightly then it’s a cylinder head valve issue.