Engine/Transmission (1998.5 - 2002) B20 starting to gel around 32?

[JPulliam]

The other night it got down to the low 30's, and when I left my folks' house I noticed that my fuel pressure dropped to 10 - 11 psi at idle. By the time I got home, 30 min, it was back up to 15 where it should be. I put the specified amount of white Power Service in last night before I shut her down for the evening. This morning it was about 34 degrees, and my fuel pressure stayed 8 - 9 psi. By the time I had driven 45 minutes or so it was back up to 15 psi again. Is the fuel waxing up? I take the pressure reading after the filter, so that would make sense that the filter is getting full of wax, and dropping the pressure on the pump side. I figured the Power Service would work, but it clearly did not. Thoughts?

 

[JLandry]

If it helps any, I've noticed this same basic behavior with both regular diesel and biodiesel blends (lower pressure when cold and higher pressure once the fuel has warmed from circulating through the VP44). I'm not sure it's a biodiesel issue per se.



You might try replacing the fuel filter just to rule that out as a contributing factor.



Best regards,



John L.

 

[DFerverda]

It all depends on the feedstock of the bio. If it was made with hydrogenated oil, it may cloud at 50 d f. When it gets real cold, and your going to run bio, keep a couple gallons of K1 and dump it in the tank,(if the bottom falls out temp wise) it will cut the bio and help the jelling issue.
Power service will help some, but does not work on bio as it does with diesel.
I got caught once with 70% bd in my tank, when the temp dropped to -12, the truck would start and run, but NO fuel pressure. I flooded it with K1 and got it warmed up in the shop and pulled 1/2 of the fuel out and filled it back with diesel and it was fine, used the rest of the fuel after it warmed up... .

 

[JPulliam]

I topped the tank off with 22 gallons of number 2 and the required dose o Power Service last night. She has been plugged in all night, so we will see what that did for fuel pressure. After about 45 minute of driving last night it came up to 13 psi from about 7.