1998 502 Mag Wont Start
#31
Platinum Member
Platinum Member
#32
Registered
Thread Starter
Okay sounds like a new pump is needed. Any recommendations for a model pump to purchase? Looks like the oem part isnt available anymore. I'll probably replace the regulator while I'm in there.
#33
Registered
I used a pump from the ROP shop , $65, it's generic so it's a roll of the dice. You can buy an entire new cool fuel assembly with pump regulator and cooler from Merc if you are so inclined. $500+
#35
Registered
Also, there's another test you can do to check for pump vs. regulator being faulty.
With 12V to the gray wire, pump running, carefully and slowly pinch off the return line with a pair of pliers (use a rag on the jaws to prevent damaging the return line). As the line is occluded, if the pump is good but reg is bad, the pressure should be able to spike to 60+ psi (immediately release if you see this happening). If the pressure can't easily exceed 45psi with the return line pinched off, then the pump is weak for sure.
With 12V to the gray wire, pump running, carefully and slowly pinch off the return line with a pair of pliers (use a rag on the jaws to prevent damaging the return line). As the line is occluded, if the pump is good but reg is bad, the pressure should be able to spike to 60+ psi (immediately release if you see this happening). If the pressure can't easily exceed 45psi with the return line pinched off, then the pump is weak for sure.
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Gimme Fuel (03-23-2022)
#36
BEACH PARTY / HOLLOWPOINT
Platinum Member
I've got a pump from a 98 Cool Fuel setup. It's used but was working well when pulled (I built new engines - carbureted). 400 hours per the ECM, but some of that could have been key-on-only time. You can have it for $50 plus the ride (I'm in VA). I'll throw in the regulator too (green stripe).
I also have a great set of better-than-OEM injectors that have maybe 20 hours on them if you're interested.
I also have a great set of better-than-OEM injectors that have maybe 20 hours on them if you're interested.
#37
Registered
If on key up the pressure shoots to 60 but then drops off to 10 doesn’t that indicate a leak down? Once it achieves pressure when keyed up it should hold.
#39
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