Hi all I have a 97 3.9 4x2 I've been getting a 43 code multiple misfire misfire #1 #2 #3 not sure why the 2 digit code. I have replaced plugs, wires , cap, rotor, crank and cam positioning sensor, Timing gear and chain (were bad). I'm not sure why but my scan tool shows the misfire codes but nothing in the individual misfire under each separate cylinder. Checked vacuum it stable, fuel pressures 45 psi
I have rad a bunch of threads about this and it seems nobody has came up with a fix is there something i'm missing all help appreciated

 

Service manual says possible causes are:
Ignition Wires
Faulty Connections
Spark Plug, Wire, or Connector
Mechanical Engine Problem
Injectors
PCM
Ignition Coil Circuit

Here is a diagnosis chart that may help you:

 

Thanks for the reply I removed all plugs all looked good no issues there. Compression test #1 160 #3 165 #5 160 #2 145 #4 160 #6 155 So i think I'm ok there. Rechecked vacuum holds steady 20. Idle jumps between 640 and 672 I'm leaning toward pcm because i get codes #1 #3 #5 multiple misfires only on that bank plugs show no evidence of misfire.

 

I think you are right about the PCM. I replaced my motor and used the older sensors and it runs fine. I had even replaced the heads and it still threw 301, 303, 305 & 351 codes. Just get a 360! so much more better!!!