NEWBEE here so please be gentle. I've scored through posts and posts of fuel pressure issues on here and can't quite find my issue resolved. First off let me say it's a crate motor installed in a Jeep CJ7. I built it off a 93' cobra, injectors, intake, all that jazz. I don't have a thermactor, EGR or smog pump on it. the only codes that come up are emissions related. I had her running and rolling for a few weeks while I was getting the Gremlins out. Then it died in my driveway, felt like a fuel problem. So after lots of research and reading I changed the FP. (It was a GM version from Novak, doesn't work when 12volts is applied). K, bad pump. Bought a Walbro 255, changed pigtails and hooked it up to the sending unit.
KO, pump primes but no pressure. Since I had to fab my own lines there's no schrader valve. OK, Has BBK Fuel rail, bought a BBK FPR and installed gauge on FPR, now I can check for pressure. No pressure at the gauge, removed FPR rotated the Vacuum line towards passenger side. Cranking over had almost 10lbs bouncing and acting like air in the line, also leaking fuel at fitting. Guess I should include she runs great on Ether. Removed FPR (again) rotated Vac port towards driver side (not on purpose) tightened up fitting for gauge. No leaks, no pressure now. With key on it primes(no pressure) but sounds like fuel is going back into the tank from return line. I have spark, pulse and a rebuilt computer, Guy says it's power module was bad and sending distorted voltages out. Made sense, not enough voltage to run the pump, not enough fuel pressure. Getting ready to drop the tank(again) Inertia -Good, 12-volts at pump-Good Pressure at rail, no Bueno. Probably going to do a rig job from pump to pressure gauge to try and sort this out. Going to remove the line from the rail and pump and blow from motor back, mabye previous check valve is in there, I dunno, any sweet words of wisdom would be appreciated.
KO, pump primes but no pressure. Since I had to fab my own lines there's no schrader valve. OK, Has BBK Fuel rail, bought a BBK FPR and installed gauge on FPR, now I can check for pressure. No pressure at the gauge, removed FPR rotated the Vacuum line towards passenger side. Cranking over had almost 10lbs bouncing and acting like air in the line, also leaking fuel at fitting. Guess I should include she runs great on Ether. Removed FPR (again) rotated Vac port towards driver side (not on purpose) tightened up fitting for gauge. No leaks, no pressure now. With key on it primes(no pressure) but sounds like fuel is going back into the tank from return line. I have spark, pulse and a rebuilt computer, Guy says it's power module was bad and sending distorted voltages out. Made sense, not enough voltage to run the pump, not enough fuel pressure. Getting ready to drop the tank(again) Inertia -Good, 12-volts at pump-Good Pressure at rail, no Bueno. Probably going to do a rig job from pump to pressure gauge to try and sort this out. Going to remove the line from the rail and pump and blow from motor back, mabye previous check valve is in there, I dunno, any sweet words of wisdom would be appreciated.