I have an 02 automatic 3.55 gears and 35 inch Toyo's. I also have Predator 100hp chip 4'' exaust and BHAF. I weigh in at 16,000 fully loaded. My problem is I can't seem to pull a hill faster than 45. It does great in the flats with good power. Also when pulling a hill sometimes it will act like you just turned the ignition off for maybe 1 second and then back to normal. We have some steep grades here in Idaho. So maybe thats all she'll do.
Do you have a fuel pressure gage to monitor the lift pump pressure? Sounds like you may be starving the high pressure pump of fuel. This may sound corny but, have you changed the fuel filter lately? Does it only cut out when your on a setting over stock? I'm tending to lean toward low fuel flow to the injection pump. Good luck.
It is going to be hard to help you without knowing how steep a grade the hills are or how long are the hills. I am going to take a guess that your truck may weigh as much as 8000 lbs. If this is true then you are pulling 8000 lbs. With this information in hand I am going to tell you that your 35" tires and your 3.55 gears are going to be to blame. I am also going to guess that your stock tires were around a 31" to 32" tall. If this is accurate then you would need 4.10 gears in the truck to make it feel like it was stock. I know that you said you have performance upgrades and all but, 3.55's and 35" tires are going to make your truck work harder than it would stock. Again, the hill grades and distances would help. LT.
It's almost definantly a fuel delivery problem. What does your fuel pressure guage say when you are pulling those hills? If it cuts out for a second sometimes, it's starving for fuel. Most likely you have a bad lift pump and the injection pump just can't make the fuel flow from it being starved. Keep driving it this way and it will eventually burn up the injection pump too. Second thing I would say would be a bad IP itself. That happened to us, good fuel pressure but the pump was going out and weren't getting good power. You are likely pulling about 9K right? Even with 35's you should be able to 55mph+. With your box on 100HP, what is your pyrometer readings pulling hills?
Sounds like a low fuel issue, dirty filter or weak lift pump. Need to keep that fuel pressure up on the vp44 or else...
Thank you for your advice. to answer your question. I do not have a fuel pressure gauge. So I couldn't tell you what it is runing at. when I pull hills towards the top also depending on outside air temps. It will get right up to 1300 right now!!! If I just let off a little it goes right back down. I actually have had more of a problem with overheating. Until I cleaned my radiator out thanks to reading one of the forums at this sight. Yes my truck weighs In at 7500 +/- depending on how much fuel I have on so yes I am pulling around 9k.Also the hills we have here can be 1 mile to 5 miles most have so many switchbacks you can only do 35 but some the speed limit is 60 at 7-8% and those are the ones that I don't like to have the suvs pulling travel trailers pass me. Thank you for all the advice I have orderd a Fass 95 gph hope it helps.
i drive a ford but i have the same tire and gear setup,it really sucks for towing,i wish , had a 4.10 gear.are you tryin to pull those hills in od?if so that may be why you cant go past 45,egt's were od luggin high to.
