BEALEAF

Just changed out stock lift pump because my truck died like someone had turned the ignition key off. Repair shop replaced old lift pump with FASS DDRP 04 lift pump. Everything seemed ok for a few days (ran good and accelerated fine). Today I took it out on the highway and as soon ad I put my foot into the gas/diesel peddle the engine felt like it was sputtering and wool only increase speed over a long distance. Stepping on peddle to kick it into overdrive was futile. Engine just *******/ hesitating on under load. I replaced the fuel filter just to make sure that wasn't the problem, but that was a waste of money as nothing changed. Anyone have any suggestions on what might be wrong. Could the new FASS lift pump be defective?
Thanks

Bealeaf.

C Schomer

I'd check pressure at the CP3 to be sure nothing went wrong with the pump or anything. My APPS recently went south and it did all sorts of screwy things. Loosing some top end power was one of the first symptoms but it took a lot longer for the really bad problems to start and once they did, it was a quick ending. Craig

BigIron70

Check for codes first? Air filter new? All sensors reading properly, possible boost sensor defective. Check all boost hoses for leaks, check fuel quality and fuel volume in spec. What is set point pressure and running pressure at rail? Max boost pressure reading. Like to help but need something other then no power, many things can cause that.