chris's ws6

iTrader: (1)

I have a twin turbo(incon) T/A with a built 9:1 bottom end. I went to get the car dynoed with 60#injectors, stock lines, stock rails, one high pressure 255lph walbro pump, and an aeromotive rising rate fuel pressure regulator. The car was at ten pounds of boost and was doing fine(fuel pressure was rising and holding to redline) until I tried to use my greddy profec-b spec 2 boost controller. It wasn't working(boost controller) it was spiking to 14#'s and dropping back down to 10. When this happened the fuel pressure started rising from the 60#'s of pressure at idle to 70#'s under boost but when the boost would drop the pressure was dropping down to only 40#'s. We unhooked the boost controller and the car was back to running 10#'s of boost all the time but the pressure was still rising and dropping down to 40 at redline. The shop I was at said it sounded like a volume problem and that the injectors were supplying so much fuel that the pump couldn't keep up so they recommended I switch to a dual pump setup. So I did 2 walbro gss340 pumps, -8 feed line, speed inc rails, moved the fuel pressure regulator from the back of the car to the front by the rails, and ran a -6 return line. Now I got the car back and the fuel pressure won't hold 60#'s at idle it will hop between 58 and 62. I decided to drive the car and got 1 block from my house and the pressure for a split second dropped to 0 and the car almost stalled. I drove it straight home since it's now 11:30 p.m. and the shop that did the work is closed. I was just wondering if you think the original diagnosis of there being a volume problem which was why they said I should go with a dual pump setup was correct to begin with or if you think it might have been something else. Plus, what do you think could be causing the new problem of the car not being able to hold fuel pressure at idle. I have replaced everything in the fuel setup except for the aeromotive fuel pressure regulator. I would think it has to be either the pumps, which are brand new, or the regulator. Any help would be greatly appreciated.

onfire

iTrader: (17)

I'd check the regulator. I'm running an incon set-up with the incon regulator and all factory lines plus a walbro and don't have any fuel issues from 10 -14 psi boost. Some regulators get funky over 50psi if they are not calibrated for the ls1 high fuel pressure.

chris's ws6

iTrader: (1)

Thanks for the reply onfire. It turns out the shop used the factory wires to power the pumps and burnt them out(wires) even though I suggested they wire each individual pump to the battery so they can get a constant twelve volts of power. They are fixing the mistake at no charge.