Thanks to all whom have responded to previous posts.
See "Misfire at 1200-1900 rpm" and "Misfire at 1200-2100 rpm" previous.
Misfire has been traced to improper operation of the backpressure transducer valve. Removing the tube attached to the exhaust port to the intake manifold (which leads to a vacuum hose to the bottom of the transducer) and inspecting it, I found the tube to be completely blocked with carbon deposits. By thoroughly cleaning with carb cleaner, and ensuring clear passage, I was able to get the transducer to modify the opening and running behavior of the EGR. The EGR does not open initially as much and responds much more quickly to throttle and load changes.
I did replace the backpressure transducer with new from the dealer. When the same behavior as before occurred, I looked next at a possible blockage at the tube leading to the transducer.
I have replace all plugs, cap and rotor, ignition wires, fuel filter and upstream 02 sensor.
Each replacement of above parts did result in improvement in the misfire, though it is only incremental so far.
I still have a misfire at the above rpm speeds, what may I be missing? Does the 2.4 DOHC require periodic valve adjustment?
Thursday, January 21st, 2021 AT 10:55 AM