intermittent shutdown
 

Hi everyone, I need some help. I have a '94 Talari Z220 7.4 Volvo Duo-prop. It has come up with and intermittent shutdown, it happens at idle, and at speed. The boat engine just quits and then you can turn the key and it fires right back up. My mechanic thought we had it solved today because he found the main wiring harness in the engine compartment not fully plugged in. Never died after that time until he called me several hours later to take it out and test it on the water. As he was talking to me it died. He went back to the harness and as he was playing with it the fuel pump quit and then started again, so tomorrow he is going to tear further into the harness. Anyone runinto this before?

Gene

accually I have ran into that same problem on a friends boat. I too also thought that it was electrical and I went through every wire from the ignition to the motor and I fixed alot of bad wires and every time i did I thought it was fixed but then it would start doing the same thing all over again. what I found after alot of tracing down wires was that the problem was in the gas tank. there was something blocking the check valve in the tank so the fuel pump would shut off after a while and by turning the key off and then back on again it would reprime and start but after a few minutes it would die again the pump was starving for fuel because the fuel line and check valve were clogged. I would suggest startting by checking the gas tank. also water in the gas tank could cause the same problem. I would clean out the tank the best that you can and replace the check valve, the check valve is only 10 bucks, good luck with your problem and if you have any more questions feel free to ask, I can go into more detail about what I checked and went through before I found the problem.

Thanks for the info, but we took the check valve out and thru it away before we decided it might be electrical. Because of the way it just fires right back up we feel it's electrical. But at this point I will try anything. Fuel pump, Ignition swith, Coil????

sorry can you give any more info on issues

one more thing does this have the front fuel pump and rear fuel pump is it fuel injected? if it is fuel injected there is a regular fuel pump and a high pressure fuel pump and a resovoir right below the rear fuel pump which is the high pressure pump. that could also be clogged it works sorta like a carb it has a float and seat

No I'm not FI. A little more history, this started a couple of weeks ago when we were wakeboarding, not paying attention to my guages and I overheated. As I was limping back to the ramp it died, I ingested water and hydro locked. After rebuiding the pump, and checking out everything the next outing it started this problem. So i assume that maybe the hot motor may have contributed to this issue.

Hello fellow boaters. My problem turned out to be a bad diode for the fuel pump. I know everyone says a diode is good or bad, but in this case it was intermittent. On the water today and it run like a champ. Thanks for the help.

Gene