crpdm

I am at my wit's end. Two months ago, the truck started dying randomly while driving. Hot, cold, full tank, empty tank, fast, slow, did not matter. Usually it would start right up again and be fine for a week or so. Two weeks ago, it died, but would only run for a minute or two before dying again. I let it sit overnight and it was fine. It seemed like it was an intermittent fuel problem, so I put in a new fuel pump. I saw that the pump had been previously replaced and the connector was spliced in with crimp connectors. I replaced these with solder/heat shrink tubing thinking this was probably the source of the intermittent problem. It ran fine for a week, then last Friday it died on the road but would not re-start. It will fire up for about 1 second but immediately die. There was a P0335 "Crankshaft Position Sensor a" code, so I replaced the crankshaft sensor with a $12 amazon special. This made the problem worse, as it would no longer try to start and would crank very unevenly, as if the timing were way off. I was till throwing the P0355 so I replaced that sensor with a $70 AutoZone sensor and now it is back to the one second starting scenario, but no more code.

• There is no visible damage to the connector or wiring for the sensor.
• The fuel pressure is 55-60 psi and does not drop when it momentarily starts.
• I read on this forum that the engine would not spark at all if the sensor was bad, so the momentary starting points away from a crank sensor problem.
• The fuel pressure regulator appears OK (no leak from the vacuum tube)

I would greatly appreciate any suggestions as to what next to try. Thanks in advance,
Karl
UPDATE: I have seen a few postings on the web regarding a bad ground wire at the rear of the engine that could cause this problem. The ground wire appears intact and well connected. Can anyone advise where this ground wire goes after it disappears into the harness? Then I could test with a jumper without cutting into the harness. Thanks.