502mpi Vapor Lock
#23
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I have a slightly built 502mpi that is getting vapor lock. It fires up great runs hard for about 1 mile and then starts vapor locking. I can unscrew the fuel filter a bit and tighten it back up and it's good to go until you shut it off for a while and does the same thing when you start back off. Any help????
#24
artselectricinc.com
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I also had vapor lock issues after converting from carbs to Merc EFI. First I eliminated the VST and ran the return back to the suction side of the lift pump. Still had minor issues after ideling for long periods of time. Then I installed a small oil cooler on the raw water intake line and plumbed the fuel return line thru that. Both engines have ran perfect since. Fuel lines are cold to the touch now!
#25
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Just fixed this issue myself without all the pumps and crap. twin 454mag mpi's in a 312 Fastech Formuls. Dumb ass design by Merc... I moved the fuel filter off the motor to the bulkhead of the back seat. then jerked off that fuel line that merc runs right on the motor..(ahh motor runs at 160-170 but they want the gas to be no more than 106 hitting the VST.. So then I ran new S/S braided fuel lines and fitting from the filter to the mech pump then from the mech pump in front of the motor along the fresh cool water line up and over the top of the plenum, actually top-side to the VST.
Ran the **** out of it this weekend. Shut off to let the thing heat absorb and she fired right up and never bogged when I hit the fuel.. Cost me a $129.00 in fuel lines and fittings and about 3 hrs labor each.. and thats me making the lines..
Ran the **** out of it this weekend. Shut off to let the thing heat absorb and she fired right up and never bogged when I hit the fuel.. Cost me a $129.00 in fuel lines and fittings and about 3 hrs labor each.. and thats me making the lines..
#27
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Problem's back, ran the boat in a poker run last week and it did the same thing 5 times in one day. You talk about one pissed of boat owner, never could run with the pack it would always shut down after about a 1/2 mile of restarting.
#30
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Here is the part number for the Merc booster pump 862264A2....this will fix your problem. I live in the mid west and we have E-90 gas around here and every body has had vapor lock issues. I have installed this set up on many 502s and they never vapor lock again no matter the temp or what they have for fuel