454bs run grat for 10 seconds then die

"Have 2-454XL with 300 hours.I

"Have 2-454XL with 300 hours.I bought the Silverton a year ago and it sat 3 months before I could get it hauled 200 miles to Dallas. In those 3 months 1 motor started acting up. Over the winter and before I could get that motor fixed the 2nd motor started acting up. Now both motors start easily and sound great for 10 seconds then I seem to loose power to the ignition system and the fuel pump. (throttle body injection)

I've read the latest thousand or so FAQ on this site and the manuals that I can get my hands on. I think the engines are suppose to shut down if the oil pressure is low or the RPM's are below 400. I have 45 PSI oil according to both oil gauges, and I get any RPM's I desire (1000-3000 or more)

Here is what I've tried so far with no changes to the operation: 1-fuel pump, both fuel seperators, both distributor caps & rotors, all spark plugs, 1-control module (located on side of distributor), 1-oil sending unit & 1-oil alarm sender.

The oil is full and appears clean. The gas is 1 year old with stablizer and SeaFoam. I'm nearly positive that both motors lose electric after 10 second of smooth running. Any ideas?????"

I had a similar problem and it

I had a similar problem and it turned out to be bad gas. I had to pump 40 gallons out and clean the tank. A quick way to tell if it's gas is to bring down a 5 gal can of gas and stick you gas line in it and see how they run. If you have 2 engines bring one for each. My engine isn't fuel injected it may be harder if yours is. You could put a volt meter on the pumps to see if they are loosing power. Good luck

"Thanks for the 2 ideas Brian

"Thanks for the 2 ideas Brian G. Running on temporary gas tanks would be a real challenge. I would need a new fuel line with fittings. I haved proved to myself that I lose voltage at the fuel pump and distributor, but I'll redo that test. I only need to get 1 engine running, the 2nd will practically fix itself once the diagnosis is correct."

"It would be real ironic for t

"It would be real ironic for two to fail at the same time, but I would confirm that you are actually losing voltage. If you are, replace the fuel pump relay. It's a Bosch and costs about $12.00 at NAPA. It is common with automotive. You should keep one onboard so if that's not the answer, you now have a spare.

The same style relay runs the entire ignition circuit so you may want to try it there as well.

I'm not ruling out other possibilities, but this one is very likely and easy and innespensive to prove.

Good luck,
Rick"

"Ok, I bought a relay and plug

"Ok, I bought a relay and plugged it in the fuel and ignition slots. No help, but I finally got up the nerve to test the power going to the coil and to the fuel pump. Surprize, I am NOT losing power to either, both engines seem to be running out of gas after 10 seconds of idleing, and they restart immediately. The fuel and return lines do not appear to have any check or anti-syphon valves. Now I will get serious trying to find out if the gas is bad or what's happening. Help, how do I do this. I'll make a gas line and pipe it into the water seperator, guess I also need to buy a fuel pressure gauge?"