Know what code was stored would help, but in the short term, I would probably inspect the harness connections at the valvecovers (1 front and 1 rear for each valvecover). If you disconnect each one, is there oil in the connector or any burned/melted pins? Also, remove the oil cap and sniff it. Does it smell like burned electrical insulation? If so you could have melting/burning of the Under ValveCover Harnesses (UVCH, there are 2 of them under each valvecover). To do a better inspection than the sniff test (quick and dirty), you would need to remove the valvecovers or perform the following:
For each Valvecover gasket connection (5 pins each), you should not get any continuity from any of the 3 inner pins to either of the outermost pins or battery ground (indicates no shorts between injector wiring and glowplug wiring or ground).
Cheers!
