sssnyd01
Junior Member
So I have a 1993 Dodge D-150 with the 5.2L engine. About a month ago went to start the truck and is started momentarily then kind of stumbled a bit and died. Then it would not start at all. Verified spark at the coil but did not have spark of the spark plug.
I replaced the wires, plugs, cap, rotor, cam sensor and crank sensor. Set the firing order per the book and would not start. Them I removed the front of the engine to get at the timing chain and timing gears. The timing chain and gears were still intact but the "dot to dot" alignment was off by a tooth. Replaced the timing chain and gears as well as realigned the dots. Also, I removed the driver side valve cover bared the engine over to TDC compression on cylinder #1 and verified the rotor position which was not point a what should be one on the cap, it was two places counter clockwise. I reassembled the front end of the engine set the firing order on the cap based off the new position of #1 and the truck fired right up.
Now here is where the story gets interesting. Took the truck for a test drive and drove great until the engine warmed up and then begin what I call the shuttering. A total momentary global loss of spark in all 8 cylinders. But if you mash on the gas it stops, if you are coasting or decelerating it stops, it is only when cruising or light acceleration from a stop after the engine warms up does the shuttering phenomena happen. This lead me to think it was related to open/closed loop fueling. Unplugged the PCM coolant temp sensor and the O2 sensor and the same behavior existed once the engine came up to temp. I tried swapping in a different PCM from a friend and the same behavior was present. I am running out of ideas and patience. My next thought is to start replacing all the sensors that feed into the PCM…. Any advice would be greatly appreciated.
I replaced the wires, plugs, cap, rotor, cam sensor and crank sensor. Set the firing order per the book and would not start. Them I removed the front of the engine to get at the timing chain and timing gears. The timing chain and gears were still intact but the "dot to dot" alignment was off by a tooth. Replaced the timing chain and gears as well as realigned the dots. Also, I removed the driver side valve cover bared the engine over to TDC compression on cylinder #1 and verified the rotor position which was not point a what should be one on the cap, it was two places counter clockwise. I reassembled the front end of the engine set the firing order on the cap based off the new position of #1 and the truck fired right up.
Now here is where the story gets interesting. Took the truck for a test drive and drove great until the engine warmed up and then begin what I call the shuttering. A total momentary global loss of spark in all 8 cylinders. But if you mash on the gas it stops, if you are coasting or decelerating it stops, it is only when cruising or light acceleration from a stop after the engine warms up does the shuttering phenomena happen. This lead me to think it was related to open/closed loop fueling. Unplugged the PCM coolant temp sensor and the O2 sensor and the same behavior existed once the engine came up to temp. I tried swapping in a different PCM from a friend and the same behavior was present. I am running out of ideas and patience. My next thought is to start replacing all the sensors that feed into the PCM…. Any advice would be greatly appreciated.
