Engine/Transmission (1998.5 - 2002) Low FP, hard start, and horrible mileage, Whats up with it?

[EGaskamp]

Sorry if this post gets windy but I'm having problems that I can't figue out. My first question is about my fuel pressue. At idle I get 13 or 14psi but will drop quick with any throttle movement. It may be because of the huge injectors! It has a new lift pump and filter. Thats what leads me to believe that my injection pump may be going. When I let the truck sit for more than 10 mins and it's not on a downhill slope it takes forever for the truck to crank up. I've checked for leaks and found nothing. And finally I get about 13-14 mpg. Now I realize with all the stuff I have done its not going to be very good, but I let my friend borrow my injectors on his 01 2wd reg cab dually and his mileage went from 19 to 27! And thats gettin in the throttle a little too. We checked and rechecked the calculations and all he has is a Diablo power puck! Does anyone know whats going on? Help!!! Thanks guys.



Eric

 

[RAJohnson]

Your probably right about your low fuel pressure with the large injectors. I would not think that a bad VP would have anything to do with it. You might want to replace your fuel delivery system with a after market FASS or RASP. But first do a Vulcan big line kit which could also solve your hard starting issue. Your hard starting has to be air getting in some where. As you know if the nose is up hill it is harder to start after sitting awhile. Mine did this once and I found the OEM fuel hose between the LP and FF which looked good was leaking air but not fuel. I removed it and was able to see lots of little stress cracks due to heat causing the problem. As far as your milage goes have you tried replacing the IAT yet. Plus the cooler weather could be doing some of it but not that bad.