I had my Chevy K-5 military edition blazer (diesel) converted to run on Waste Vegetable Oil about two years ago. She drives great, no loss of power, Turbobooster.
Recently, I had to get my fuel filter replaced. And she still runs on mostly filtered vegetable oil. (She had additional glow plugs put in by Lovecraft biofuels.)
She's been doing fine at speeds up to 40 miles an hour.

However, I recently took her on the freeway, and when I got her up to 60 for longer than 20 minutes, she began to lose power. The engine immediately shut off to protect itself, and I had to pull over to the side. I added some regular diesel fuel to see if that helped, but she still wasn't doing well over 50 mph.

A friend of mine said he thought air might be getting in the lines.
Anyone know anything about this? I'd love to keep running her on veggie or veggie-mix, as it's better carbon dioxide emissions.

Thanks so much!

 

Make sure you are getting enough pressure from the fuel pump.

 

"Engine shut off to protect itself"

Was it getting hot?

How clean is the bio you've been getting? Might be garbage in the lines. Re-checked fuel filter?

Any problem restarting after shutdown?