An interesting thing happened today. I run a Frybrid system but have been using dino for about a week while I clean my drums and check mpg's. Today after topping off the dino tank, I switched my Frybrid system on. Within a few seconds my check engine light (SES) came on and the engine sounded noticeably different, noisier, rattly. I hit the purge button. The SES light went out, but then while on diesel my engine revved on its own for a few seconds.

Any thoughts?

After scanning the ODB1 with my trusty paperclip, I pulled code 34 which is the "DTC 34 - Injection Timing Stepper Motor Fault". I tried VO again on the way home from w*** and again the engine raced and the SES came on. The beast runs fine on dino. What does code 34 mean exactly?

The Powertrain Control Module PCM controls injection timing with the injection timing stepper motor. To increase injection timing the PCM extends the stepper motor. To retard injection timing the PCM retracts the stepper motor.

DIAGNOSTIC TROUBLE CODE (DTC) 34 WILL SET WHEN

Engine operating at steady RPM.
A 50 difference between measured and desired injection timing for 20.8 seconds ACTION TAKEN PCM will default to)
None.

DTC 34 WILL CLEAR WHEN
The fault condition(s) no longer exist.