Three Letters Re: Diesel Engine Vehicles and EMP

1.) Jim:
GM diesel models 1994 or later have an electronic injection pump, and are vulnerable to EMP. Some models made before 1994 will have an electronic glow plug controller which can be easily bypassed. From what I can gather GM also went to “electronic” transmissions around 1994. Before then most diesels had th350 or th400 transmissions. Some pre-1994 GM trucks also had th700r4 transmissions that had minimal electronics, and can be rebuilt with the electronics bypassed. Of course anything with a manual transmission should be safe. I believe most light diesels follow the same timeline because of EPA smog regulations that were implemented at the time. – C.G

2.) I just had to replace the glow plug relay in my 1982 Mercedes 300SD, and took the old one apart and found some transistors in the turn-on timing circuit. These may get fried, but I can always put a pushbutton on the dash to simplify the circuit. – A Marine Corps Reader

3.) Hi,
I can only speak for Fords, of which I own a 1988 F250 Diesel. The early 80’s to 1994 ford In-Direct Injection (IDI) 6.9L and 7.3L diesels,
actually an International motor, have no computers. Everything, and I mean everything, is mechanical in these motors (even the fuel pump). In
1989, Ford went to a 4 speed automatic transmission that is computer operated, and that is the only computer in the truck. Of course, there
are electronic components in the truck: Glow Plugs, Alternator, Gauges, etc, but the truck would keep on running and driving even if it took an
EMP hit. If the glow plug controller goes out, it might be a little hard to start on cold days. Losing the electronic starter would cause
problems too. After 1994, the Ford diesels are called PowerStroke, and they have computers controlling the motor.
My ’88 F250 4×4 Diesel is my G.O.O.D. vehicle for good reason! – “Analog”