Today I went to have my truck tuned for the second time in two weeks. Last week I was sent home because my truck wasn't making boost at the intake. I fixed this problem by relocated my boost reference to the front of the truck and I return today and now I am loosing fuel pressure. I have a Walbro 255 and 42 lb. injectors in the truck now. My buddy had it on his dyno and at WOT it will be at 55, 60 then will drop off to about 40 at around 4200 rpms. They suggested taking a look at the fuel pump...Anyone else had this problem? The first thing I am going to do is change the fuel filter tomorrow and go from there. Any input is appreciated!

 

That's a good place to start. How much boost are you running?

 

on low boost about 5 lbs. and with boost controller about 8lbs.

 

any ideas?

 

You can check your FPR on your fuel rail. After a drive pull the vacuum line off and check to see if it is wet. If it is then it is leaking fuel and needs to be replaced. Make sure your tank is at least half full.

 

ok, just did that...it wasn't wet but I decided to replace it anyway just to eliminate minor things before having to go into the tank...so thats...fuel filter and FPR ive changed...I am thinking its a cracked line to the pump because it will spike pressure then fall. If the pump were bad wouldnt it just give low pressure regardless?

 

UPDATE::::My problem was the fuel pump, it just simply went out...turns out i had a racetronix pump not a walbro...which i was told i had when it was installed. I have a new set of problems on my hands now. After installing the pump i took it for a drive, did fine until i gave it WOT then it knocked down the power like my tank was empty but it wasnt of course so I took it back to my house and noticed that the boot connecting the last charge pipe to the TB was collapsing when WOT and starving the motor for air. Easy fix with a piece of pipe inside the boot to give it structure. Nest drive did the same thing at WOT only. AFR is 10.5 at WOT so very rich... What the hell is my problem now? When I took it to get it tuned they told me I was losing fuel pressure bc he kept adding fuel and it would go lean again...me fixing the pump and still having that added fuel...could it literally be flooding my engine bc too much fuel? HELP!!!