hotrod04

iTrader: (1)

Is it possible to create a fuel pressure drop with a tune? I have 63lbs at idle,63lbs at cruise and at wot drops to 50lbs. I have checked the install of the walbro 255 twice and everything is ok. I have 43lb injectors and at the fuel drop in 1st gear it wont rev past 5000 rpm's and 2nd gear 4500 indicating it is running out of fuel? 2004 5.3 which is a returnless fuel system. I need help this has gone on to long thanks.

hotrod04

iTrader: (1)

Could someone help?

foff667

iTrader: (2)

are you running an fmu or trying to tune out the fmu?

hotrod04

iTrader: (1)

I have a tune from Allen.

foff667

iTrader: (2)

so you have no fmu just so I understand? has it always died at 5000? or is this something recent and immediately after the tune you had no issues?

hotrod04

iTrader: (1)

Did everything at the same time, sts turbo, injectors, pump and tune.

hotrod04

iTrader: (1)

Also went with NGK tr6 spark plugs.

foff667

iTrader: (2)

you still havent anwsered my questions...im sure the sts turbo kit comes with an fmu like most other forced induction kits...are you using the fmu at this time? When they did the tune did they just give up because it kept dying at 5000rpms or did it work fine while tuning then afterwards it stopped working right?

hotrod04

iTrader: (1)

Allen Nelson is a mail order tune, recomended by STS. Not sure what fmu is?

foff667

iTrader: (2)

aight after talking to a fellow board member i received this:
"we had a kids car doing that and it was his weak springs floating the valves. The kit comes with no fmu. He needs to autotap or efi live it to know for sure. Also I know my maf is maxed by 4500 and then it goes into open loop under wot. These are all guesses but without the car being logged it could be a bunc of things."

so there ya go, gives ya a couple of things to look at temporarily