Engine/Transmission (1998.5 - 2002) Thin hot fuel ??

[Turbo Terry]

I have a 99 with a RASP and stock lift pump backup. On a recent trip using X brake and climbing up and down grades truck got very hot(water temp) due to filthy radiator. My fuel pressure normally runs 12- 14 lbs. with the sending unit mounted on top of the fuel filter canister. It was a rather hot day for here and my fuel pressure dropped to 7-8-9 lbs. then the stock lp was on for a short while. I pulled over and did the 1500 rpm in neutral cool down and my pressure came back to normal. The backup lp had taken over but not enough to bring the pressure up past the 7-8 lbs. to make the light go out on the Hobbs switch. I think the fuel was so hot and thin in the sending unit that gauge lost pressure for a moment and the hobbs switched it over to the stock lp. I also think my lp might be stuck. Its a very new lp. Thoughts or ideas appreciated. Thanks

 

[tgee]

You probably wont notice a drop in pressure with hot fuel, although i'm sure there is some, not much, You should notice some power loss, I think something like 2% for every 10* above 110*.

 

[Turbo Terry]

Why the power loss I wonder? I didn,t really notice any power loss but the cooling system was very hot due to the the dirty radiator. My LP is seized up and will not run at starter bump so I will change it out. Its running just fine on the RASP but I will need the stock LP to change fuel filters etc. Thinking about getting rid of the lp and putting something from Glacier Fuel to be the backup etc. Will work on this in the fall when I have more time. I did take the belt off the RASP this AM and zero pressure at the gauge. Interesting as the LP is two months old.