Need OSO collective help on 502 Mpi
#1
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Need OSO collective help on 502 Mpi
Okay all, having a fuel problem on my rebuilt 1999 502 Mpi. Not making enough pressure. It s bouncing around 30-38 lbs but when you pinch off or remove the vacuum line going to the plenum it gets a steady 43 lbs. I have replaced the fuel pump, regulator, anti siphon/ fuel shut off valve, all injectors, and the pressure line from the seperator to the pump. There isn't a whole lot of stuff left to replace except the fuel cooler and the line going from pump to rail. HELP! I've spent a year and a half rebuilding everything on this boat and now it's done and this dumb little issue is keeping me from running the hell out of it. Can any of you 502 Mpi experts help me out?
#4
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Thats my first thought as well,,,,,good luck !!!!
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#5
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Okay. Didn't get a vacuum gauge yet but I unplugged the vacuum line and ran the boat today. Ran like a bat out of hell, 4800 rpms. So that brings the question, why does bypassing the fuel regulator by unplugging the vacuum line make it run right? It is a new regulator, do you think the regulator I got could be bad? Since it ran so well I don't believe I have a stuck valve or a valve issue. What do you think?
#6
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fixx
Okay. Didn't get a vacuum gauge yet but I unplugged the vacuum line and ran the boat today. Ran like a bat out of hell, 4800 rpms. So that brings the question, why does bypassing the fuel regulator by unplugging the vacuum line make it run right? It is a new regulator, do you think the regulator I got could be bad? Since it ran so well I don't believe I have a stuck valve or a valve issue. What do you think?
#7
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I did not change the cam. So without vacuum it was just running full fuel pressure no matter what throttle? How do you reprogram the ecu?
#9
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I thought about doing that but didn't figure it was an electrical or computer issue. Blackwood told me to send my ecms out to that place in Arizona to remap them.