What's causing my misfire?
Grand Champion
Joined: May 2019
Posts: 5,156
Likes: 721
From: S.W. Indiana
Ah, good to know. While I guess I should definitely change the timing chain soon (thanks for the tips), how would I actually verify that that is my problem? I do not want to go through the chain change and still have the misfire. I do not presume it is because of the plugs since only one is misfiring (I stayed away from Bosch plugs). How do I actually diagnose where my misfire is coming from? How do I know it isn't PCM or injector wiring related?
If you need to replace the water pump go ahead and do the chain too as 80% of the work is already done. On these trucks, it's a bit labor intensive due to how the distributor is tucked away in back. Put a white mark with soap stone or something on the harmonic balancer. Rotate the engine by hand using a socket and put it at TDC on the timing mark. Remove the distributor cap and using a paint or other marker, but NOT a pencil, mark where the rotor is pointing. Now rotate the engine backwards slowly until the rotor starts to move in the distributor. 3 or 4 degrees is okay. 5 or 10 or 15 degrees is not.
