My friend and I have been working on a v6 4.3 Gi Volvo Penta Princecraft for a good month now. The people who own the boat got water in the fuel system somehow and it basically wiped out the whole engine. We have changed the map sensor, TPI, IAC, Ignition module, rotor, and fuel pressure regulator and still this boat will not run correctly. We now have basically narrowed it down to possibly either the intake manifold, or the ECU has been fried. SO, I have come here for possible answers before we blow up a boat! There are symptoms such as, VERY hard to start sometimes with backfire up through the throttle body, but when it does start it runs fairly well. Randomly will cut in and out when throttling the boat. If any answers could be reached on the subject I would greatly appreciate it.
Did both, when we tried to get codes off the boat it didn't bring anything up.......We have called the president of the Volvo Penta company and he was just as puzzled about the situation. What does this backfire from the throttle body when we try to start the boat sound like though? He did say there is a possibility that the starter modular of the ecu could have went bad.....but we really don't think thats the case
And thanks for the welcome
I would imagine a leaky intake would cause a number of problems.
I don't putz around with EFI Marine stuff too much, but when I've had back-firing issues with my cars, normally the timing being off or having the wrong firing order have been two common culprets.
-Chris
I don't putz around with EFI Marine stuff too much, but when I've had back-firing issues with my cars, normally the timing being off or having the wrong firing order have been two common culprets.
-Chris
Chris E
Member
i have not played with efi to much either, backfiring can certainly be caused by bad timing, which i beleive is run through the ecm. it is possible that the ecm has gone south, however, in my experiance, other than when new - the ecms are very reliable. you may have to try and swap it out - or send it to volvo for reprogramming. it would be nice to know for sure before you went to that trouble.
I think youve still got water in the system somewhere..may in the fuel injectors or the associated plumbing. If the engine has been static timed, that should be a good start, as far as timing goes. The orifices on EFI are so small that water will actually work like a plug and not atomize, in some sytems anyway, Good luck