Attention: TDR Forum Junkies 
I had an interesting thing happen with the truck today. I had to drive back to school (about 100 miles) after being home for the weekend. Right now my heated tank has about a 50/50 mix of WVO/kerosene. The truck ran great the whole way back, fuel temp was good, as was fuel pressure. Just before campus, I clicked it over to purge mode, and then pulling up to the parking lot, I switched back to diesel. It suddenly started running really rough, as if only about half of the cylinders were firing. I limped it into a parking space, and shut it down. Restarted, and still the same thing. I pulled the following codes:
P0500 - No Vehicle Speed Sensor Signal
P1693 - DTC Detected In ECM Or PCM
P0251 - Fuel Injection Pump Mechanical Failure Fuel Valve Feedback Circuit
P0252 - Injection Pump Fuel Metering Control "A" Range/Performance
P0234 - Turbo Boost Limit Exceeded
Next thing I did was borrow a friend's scanner (he has a '98 24v) and double check the codes. All it did was find the overboost code (which is unusual, because I haven't fooled with any of that stuff, and it was also dated 1/06), so I cleared it, and then disconnected the batteries for a few minutes. After hooking the batteries back up, I couldn't get any codes from the odometer or the scanner, so I fired it up. It ran rough for about 10 seconds, and then started hitting on all six again, and now it runs fine - no codes at all.
I know that running WVO isn't the ideal thing to do with the VP44, but I've talked with people who have run them more than 100k on grease, and with the FASS I'm able to keep plenty of fuel supplied to it. I'm wondering if I sucked an air bubble somehow and that just threw the computer for a loop? Anyway, it's back to normal, I just figured I'd share the experience.
P0500 - No Vehicle Speed Sensor Signal
P1693 - DTC Detected In ECM Or PCM
P0251 - Fuel Injection Pump Mechanical Failure Fuel Valve Feedback Circuit
P0252 - Injection Pump Fuel Metering Control "A" Range/Performance
P0234 - Turbo Boost Limit Exceeded
Next thing I did was borrow a friend's scanner (he has a '98 24v) and double check the codes. All it did was find the overboost code (which is unusual, because I haven't fooled with any of that stuff, and it was also dated 1/06), so I cleared it, and then disconnected the batteries for a few minutes. After hooking the batteries back up, I couldn't get any codes from the odometer or the scanner, so I fired it up. It ran rough for about 10 seconds, and then started hitting on all six again, and now it runs fine - no codes at all.
I know that running WVO isn't the ideal thing to do with the VP44, but I've talked with people who have run them more than 100k on grease, and with the FASS I'm able to keep plenty of fuel supplied to it. I'm wondering if I sucked an air bubble somehow and that just threw the computer for a loop? Anyway, it's back to normal, I just figured I'd share the experience.
