502 Mag vapor locking???
06-25-2008 | 07:09 AM
#15
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Posts: 841
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From: edgewater,md.usa
I also have a 502 mag efi, on real hot days one engine will be very hard to start. After a short idle on the other engine it will start. I have the cool fuel system. Will the booster kit fix this issue. It seems to be a vapor lock issue. If I leave the hatch open while parked it will sometime be ok.
06-25-2008 | 08:28 AM
#16
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Joined: Feb 2001
Posts: 4,018
Likes: 21
From: Clearwater, FL
I also have a 502 mag efi, on real hot days one engine will be very hard to start. After a short idle on the other engine it will start. I have the cool fuel system. Will the booster kit fix this issue. It seems to be a vapor lock issue. If I leave the hatch open while parked it will sometime be ok.
If you do not have the mechanical pump mounted on the sea pump the kit will help.
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07-03-2008 | 03:39 PM
#17
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From: Nashville, Tennessee
I checked that first and all looked good with no water or anything...starting to think im going to have to drop the $300 for the kit....she's still acting up. appreciate the help though
07-13-2008 | 02:51 PM
#18
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Joined: Jun 2007
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From: Union, Ky.
i have a 97 outlaw with a 502 Mag....basically it runs flawless when i first start it up and run it cold....when i sit all day and go to leave it fires right up again but when i go to take off it sputters and wont plane out....i can throw it in neutral and it barely will idle...ive been pumping the throttle trying to clean it out and it usually will kill it....it does that a couple times (2-3 minutes) and then all of the sudden it will just fire right up and run perfectly again? It also doesnt do this every time, its sporatic but always after i run it and then sit for a while. vapor locking? fuel filter? anyone had this problem or ideas where to start looking?
my 1994 baja 454 magnum efi is having similar issues. so far noone from michigan to texas has been able to figure it out.
my repair shop has replaced the mech. fuel pump, fuel pressure regulator, IAC, and water fuel sep.,
on wed. of this week i went on the test ride after they replaced the fuel pressure regulator. it ran great for an hour or so. the next morning i fire it up to do some checks and it ran on the hose to 150-160 degrees. i shut it down to do some things and about 30 minutes or so later i restart it and it ran for about 10-15 minutes. then the problems started again. similar to yours. the IAC opens and it falls on its face. i have a 6 page thread located here....http://www.teambajamarine.com/forum/...ad.php?t=15047
it's a LONG thread. this has been going on for 2.5 weeks.
its driving me and everyone else nutso. i have disregarded vapor lock because it has always restarted, but won't idle and just stalls. high pressure fuel pump reads 36psi at all times (per repair shop). this boat will idle for 25-35 minutes and then stall. this has happened 4 or 5 times since thursday morning. wednesday afternoon it ran on the water for an hour or so and did not even hiccup. me and 50 other people are stumped.
any help is appreciated.
07-30-2008 | 05:02 PM
#20
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From: Nashville, Tennessee
ok still chasing the gremlin down....i have the mechanical pump already on my boat after looking into it some more. i hooked up the fuel pressure gauges to it and its showing 31psi when its running fine....after i ran it and sat for a while it started right up like normal - like it always does - but as soon as i started to take off again the pressure dropped to 20 then flat lined and there i sat....i was told 30psi was low? anyone know what they are supposed to be pushing stock?
