sdonzi

Looking for some tips with my 1996 502 EFI. Recently it cuts out and shuts down at wide open throttle. It runs fine if I keep the speed down near 60 mph and under, but once it gets up near top speed it cuts out and shuts down. It does not do this every time, but it is getting frequent enough to be a pain in the ass! And no I am not over reving the engine. The boat wont even get to top speed/rpm before it cuts out, and as I said its not happening all the time. Also when it does happen it always starts right back up no problems at all!! The last time I was able to pull the throttle back fast enough to keep the boat running and it did not stall out.

I have replaced the fuel and water seperator and this was not the problem. As I said the boat runs great when I am not running at speeds above 60mph. Help?????

tomtbone1993

iTrader: (3)

rod for the fuel pump is worn, computer may be shutting it down.

just a guess, I had it happen to me before.

baywatch

I had a similar issue @ 3500 rpms. It would shut down @ that rpm but if I gave it more throttle it would come out of it. It ended up being the ignition harness. It was like a $35 part too bad I spent $70on the TPSpart replacing the throttle positioning sensor first..

specialk

Make sure you check the obvious such as corrosion around distributer cap and rotor first. I had a problem where the pick up tube for the fuel in the tank had a crack at the very top. It would cause it to run out of fuel at higher rpm but run fine all day at low loads.

Young Performance

It really sounds like a fuel delivery problem. I would put a fuel pressure gauge in and run it. You can install a temporary one in the fuel rail and see if it drops at upper rpm. You should be able to pick up a cheapy gauge at the auto parts store. Hope this helps, Eddie.

camptappakeg69

Had the same issue with mine, does it have vst?

Electric fuel pump screen in the vst was clogged. would run fine untill over 3500 rpm......then would cut out.

sdonzi

yes is has VST, so you think I should check the screen first??????

Tubby

I had a pair of 502 in a 33' Donzi and had the same problem with the port motor. These were EFI and it turned out to be the pick-up coils, so I had both distributors rebuilt and it took care of the problem.

camptappakeg69

Thats what my symtoms were, would run fine till about 50mph or just over 3800rpms, was starving for gas. pretty simple to check, just may need a new seal for the vst tank.

Also this had to have that electric pump replaced, was causing all kinds of issues when up to operating temp, wouldn't idle sometimes, would surge rpms, and plain old run like chit...........