12v in 1990 f350 issue
 

ok ive had my truck done now for almost 2 years ever since i put the cummins in the ford iv had very low to no boost ive noticed my egts are higher than in the dodge and i dont have the low end spool up turbo makes at about 10-15 loades rely pushing it with the size turbo i have and fuel mods i was making 40psi+in the dodge since i started diagnosing i have done a 3piece ported manifold, ported turbo and custom high flow downpipe and no change could it be to small of fuel lines? thats the only thing else i can think of because you need fuel to make boost and boost to make more fuel?

I guess it could be possible. I would see where your fuel pressure is at and go from there.

well i do remember in the dodge with the pump turned all the way up i could flat black out a freeway in my older age im going for power not smoke. i turned the pump all the way up yesterday and still seems to be lacking the boost situation is still the same , i did an intake system check and no leaks

Do you have a draw straw or anything like that in the tank? Its possible the pickup in the tank could be too small causing a restriction.

fuel tank
 

I have heard that the screen in a gas truck will not let enough fuel through for a diesel might try a electric lift pump you have to move 90 gallon an hour the stock manual pump provides 90 gal hr at 7-12 psi depended on the rpm when my lift pump went out for the 3rd time I replaced it with one similar to this

ebay item # 390367125264

might be a good test or put a psi gauge on to test pressure

I posted a reply to this in the distress thread that i don't want to re-type

well the entire ford fuel system up to the lift pump is what im running and the truck was a 7.3 non turbo diesel im gnna check the lift pump screen and change the fuel filter and see what happens i dont have a draw straw but if its the fuel system thats next on my list i would like to find the cause before i get to redoing the entire fuel system especially with dual tanks

is it smoking worse?black?white?

well im leaning toward low fuel do to the fact the fuel components im running and the pump maxed out it doesnt smoke black like it should normally i have everyhting tuned so i dont get smoke but when i built this truck i havent had the boost to tune it yet anyway im almost debating on running a bypass line into a tank with actual 3/8 rubber fuel line and see what happens. i dont exactly know what size ports the fuel valve is being dual tanks but im sure it does restrict to a certain degree. with the mods im running i was pushing 45psi+ with it in the dodge

When I had my 1st Gen Cummins in my '93 F-250, I ran the stock Ford IDI diesel fuel system up to the lift pump on the Cummins and I never had a problem. However, when the sending units went out in the tanks, I dropped them and found out that the rubber funnel/baffel at the end of the pickup tubes were all "melted" and gummed up the end of the pickups. I did notice that when I put the 2nd Gen Cummins in and turned up the pump that it seemed like I could never get enough fuel to it with the stock 2nd Gen mechanical pump. I ended up getting an AirDog 150 and ran 1/2" line and a draw straw from the rear tank to the engine, and just use the front tank as a "transfer tank" with a small Carter fuel pump between it and the rear. I'm trying to come up with a way to make a 1/2" ID transfer valve assembly so I can straw the front tank and switch on the fly, but I've been pleased with the current system, especially since adding a 33 gallon rear poly Bronco tank.