I've got strong spark. Confirmed my other tests for that by pulling fuel pump relay and shooting a little ether in the throttle body. It fired right up.
The fuel pump is working too. In fact, I've got too much fuel on cylinders 1 and 2. Consequently no fuel on 5 and 6. And that leads me to the problem. Skip ahead after a few more tests.
The PCM is grounding all the injectors continually (even when the ignition switch is off). So, the injectors are all open all the time once the switch turned on and B+ is supplied.
It's not the injector harness itself. I pulled it and tested. The harness leading to that one does not have the melting problem that sometimes occurs with these vans. Checked for that too. When I disconnect the PCM the grounding goes away. So I tried another PCM from junk yard (cheaper way to rule out bad PCM) and still that same continuous ground to the injectors.
So I'm looking at an input problem to the PCM. BTW both the camshaft and crankshaft sensors have now been replaced while on this journey because both showed OL on the ohm meter (maybe they got fried by whatever is tricking the PCM).
I'm kind of at a loss. Looking for a short or broken wire coming into the PCM but need some pinout guidance that Haynes and Chilton's don't provide.
Thursday, January 23rd, 2025 AT 8:04 AM
