Historically, the speedometer in my '93 F350 4X4(E4OD) has had some irregular spastic activity at or above 70mph. Also, I've had an issue with fuel delivery from the rear tank, which may or may not be relative to my current situation. The truck runs good off the rear tank at local highway speed(60mph or less), but the engine will sag under load, especially uphill, forcing me to switch to the front tank. When the truck is parked for much time while switched to the rear tank, the fuel apparently draws back to the tank, leaving the line with air forcing a lot of cranking and hard starting. This never happens when it's switched to the front tank when parked.
I pulled a trailer from SW IA to Denton, NC this weekend, 1200 miles pretty much straight through on Friday. Nothing really out of the ordinary getting down there. Left there today, and shortly after I hit the road I switched to the back tank after climbing a long grade. When I switched the tank selector the speedometer dropped to zero, forcing me to take control of the transmission by moving the selector manually. Shortly after that, the ABS light came on. After stopping for fuel the speedometer started working again, but now it bounces consistently when I change the fuel selector, especially switching to the back tank. It seems to act goofy when operating the wipers, but on a less consistent basis.
I'm wondering if there may be some bare wires in the loom that serves the speed control sensor and the fuel tank selector. Or, maybe just a speed sensor going bad, or a grounding issue somewhere. Any ideas??
I pulled a trailer from SW IA to Denton, NC this weekend, 1200 miles pretty much straight through on Friday. Nothing really out of the ordinary getting down there. Left there today, and shortly after I hit the road I switched to the back tank after climbing a long grade. When I switched the tank selector the speedometer dropped to zero, forcing me to take control of the transmission by moving the selector manually. Shortly after that, the ABS light came on. After stopping for fuel the speedometer started working again, but now it bounces consistently when I change the fuel selector, especially switching to the back tank. It seems to act goofy when operating the wipers, but on a less consistent basis.
I'm wondering if there may be some bare wires in the loom that serves the speed control sensor and the fuel tank selector. Or, maybe just a speed sensor going bad, or a grounding issue somewhere. Any ideas??
