car bucking after 255 install

[OreoTsi]

I just installed a walbro 255 fuel pump in my 91 Talon. Car currently has 550's 2gMAF and S-AFCII zeroed out.

Before the install car worked fine. After the install it bucks under boost. BADLY.

I snapped the hard line so following a thread on this board i fixed it using some 3/8 rubber hose and some AN fittings.
I also rewired the pump.
I even swapped the pump with another one to see if it was a faulty pump. No change.
Fuel pressure is at 27psi at idle. For my car it should be at 37.

Could the size of the line cause a decrease in fuel pressure? Its only about 3" of 3/8th line.

Also, car is hard to start in the morning, I'm assuming thats due to no check valve.

Any ideas?

 

[Splitpi]

I didn't think stock FPR can keep up with 255... but I could be wrong.

 

[BeanBag]

When doing a fuel pressure test, clamp the return line and if the pressure goes way up then your FRP is gone.

 

[ez1286]

You really need an aftermarket fpr with a 255 pump.

 

[OreoTsi]

problem was due to one of the AN fittings i had rigged up in the tank. It had a hole in it for some reason, and was leaking as fuel passed through it. So i had a leak in my gas line, inside the gas tank.

Car runs like a champ now, but rich at idle.

Gonna get an AFPR soon.

 

[toecutter]

Same thing happened to a buddy of mine, 255lp jacked his fuel presure to about 56psi.
He got a afpr and turned it down a bit and it pulled fine agian.