[Mary Westbrook]

Have a 2001 F 350 with a 7.3 liter engine. It's got a crank but no start, solid idle then dies suddenly like someone turned the key off. When we can get it to stay running, won't go above 45 miles per hour. Replaced the ICP and the IPR with no difference. It's pulling p1670, p0603, p1316 codes also pulled a P0 264 and p1298. When it first started acting up last week we did an oil and oil filter change and fuel filter change. Fuel filter had quite a bit of oil on it. Just need help pinpointing a cause, can't keep replacing all these expensive Parts. Tested IDM wiring harness with multimeter, driver side all read around 4.0-4.4. Passenger side all read 6.8-7.1. Any idea why so high and different?

 

[Christopher Wells]

Main cause of resistance in most cases is corrosion or cut wires. If the wire has rubbed up against something causing it to lose connected strands of copper wiring the power to the wire wont change but the path gets more narrow, like trying to push water from a thicker stream into a thinner stream, you'll get more resistance and heat. Same idea when you get corroded wires. lose strands of copper to conduct the power, make a more narrow stream for the power to flow and gain resistance. I know for a fact that the P1670 code is an EF (Electronic feeback) signal error. If you look up the troubleshooting procedure for that code it will have you testing resistances between wires from your PCM to IDM and for shorts.