drag shutting off

[rock]

I have a 260 with drag porting, pcu, SVS, etc. When coming off full throttle run, the motor wants to die. Starts right back up. I am thinking fuel but I don't know for sure. The boat is a Cougar with dual tanks and I am thinking the plumbing might be the problem. The two tanks tie together as high in the boat as possible. They then go down to the water seperator and back up to the fuel pump then another fuel filter and finally the motor. Pump and filters are mounted in boat and not under engine cowling. Could this be too many loops and restrictions? It pulls very hard and runs great all the way to 7500 and never dies except when you lift after the full throttle pull. This same motor turned 8700 with a 28ET thru 1.75 gears on my boat. This is why I am thinking plumbing. I replaced the Bosch pump with a new one and had the same results. I do not have a fuel pressure guage so I don't really know where that is. It does seem maybe the pump is trying to cavitate. Kinda sounds like maybe a little air is occasionally going thru the pump. I am not sure where to start. Is it possible the loops are trapping air and even if they are, how could that cause this type of behavior? Thanks
Rock

[pirogue]

to be honest rock it sounds more like a set up problem, by that i mean tunning svs, pcu, p/u timing, and if you have the gold svs it may also be air vavle on top of svs, it needs to be 3.5 turns out.

i have a small fuel cell in my boat and when the tank gets low, the fuel pres will flucuate between 30 and 56#'s when coming off a pass from areating. not sure how severe your fuel problem may be.

tell us more about set up you have, and i would call tony if you haven't already and ask him about all the settings on the pcu and svs. he can probably help.

i run a 300 drag with gold svs, pcu, aeromotive-fuel pump-regulator-and-filter, don't really have your problems but did have my lil quirks with set up like i explained above.

also check all your connections, grounds, pcu harness, and BATTERY CABLES!

[RUDERIOT]

Check the pick-ups in the tanks. We had one that did the exact same thing & after replacing a lot of electronics found a cracked pick-up tube.

[lokinutz]

I'm no expert, but I have heard of and seen problems running two tanks with a single fuel pump after the tee and no valves. Have you tried disconnecting and plugging or crimping off one tank's supply line? Or possibly putting in two high flow ball valves? A friend chased a fuel problem for two months until he put a pair of vice grips on one of his supply lines. Quick and easy thing to try.

[rock]

I am leaning toward the fuel system being the problem. The motor ran great on my LTV. His boat ran great with the Promax. I think maybe the extra demand for fuel is the problem but I don't understand the shutting off thing. I will try to re-plumb things and see what happens. I will also contact Tony and see what he has to say but that PCU was just updated by him about two weeks before the motor switched boats. Again, thanks for the opinions.
Rock