Diesel vehicles will still work as long as they do not have any sort of microprocessor to contol the starter and/or fuel injection pump. That's one of the reasons why the military uses diesel vehicles. The Humvees, deuce-and-a-halfs, FMTVs (I think), and larger trucks have mechanical injector pumps and very simple glow plug systems. A diesel engine, once it is started, will run forever as long as it has a diesel fuel supply. The extremely high compression ratio causes the fuel to autoignite continuously. There are no ignition parts to wear out or be disabled by EMP. Also, I have heard that electronics using vacuum tubes instead of ICs and transistors, like old High Frequency HAM radios, should still work. The Soviets are still flying some older jets that use vacuum tubes in some of their systems.