I have a 1991 Aeromate yes that is right an aeriomate made by Utilimaster from 1986 to 1994. It has the old 3.3 as the powerplant and the yucky A604 trans
Recently it lost most power and could barely pull. Discovered that it was only firing on one coil ( two cylinders ) ....... Easy fix, thought it was the crank sensor- replaced, thought it could be cam sensor replaced. Thought it could be the coil - replaced. Then thought it might be the pcm.
I have a 1992 which I can interchange the PCM and the 1992 will run fine with either pcm but the same result on the 91 as well as a few other 3.3 pcms from pull apart- only 1 coil is firing . Engine ran well before this so I was hesitant to think it was the timing chain and my gut now tells me it has to be a flexplate issue
. My snap on states I have both cam and crank signal and it will run on two cylinders. When checking the coil only one wire is sending a pulse signal - the other two are dead I have even tested the wires coming from the PCM to eliminate two bad wires . So... before pulling the trans this weekend - flexplate or timing chain more likely ? Truck has 150K but these vehicles due to their GVW sometimes over the limit makes me think more the flexplate. Thoughts ?