dossangers:
Im ready to repower my 24' i have a 330 hp mercruiser carberated its 17 years old used all the time been all over mead and mojave probaly has 3000 hrs on it the only thing ive worn out is the outdrive! i think after hearing all the problems with efi ill stick to carb motors just go bigger cubes i have a 496 in my truck its never ever gave me any problems go figure? Does Mercruiser even make a carb motor?
I just had a problem on a very hot day with the engie vapor locking. The problem comes when you do not get enough air flow into the engine compartment and the fuel lines get to hot and then its all over. I added two vents under the rear seat that allows air to flow in the engine compartment that should help.
8299, does that boat have a blower, and were you in Havasu when it quit? If you are the guys I helped, just remember; the aftermarket fuel pump you have is more than twice the amp. draw of the 'stock' fuel pump. The 'shaken' fuse is also a real fluke.
The camshaft position sensor was a silent recall on GM trucks. I have also had problems with the fly by wire throttle which failed completely and I had the entire throttle body, electronics and switch replaced on my truck.
I would say vaporlock sounds likely just as others have said. If you could figure out what section of the lines are getting hot, you might be able to insulate it.
EFI is sooooo much more reliable than carburated engines. I have had both, and I don't ever want another carb.
No Blower. Its not Vapor lock. Shit, I just saw the date when I posted. And I still havent gotten it fixed. Its an intermittent electrical problem. I'm real leery of leaving my boat with some of these knucklehead mechanics. I was hoping that the builder would just pick the boat up and handle the problem, but he just turns away and leaves it up to me. It's going in next week to a local Merc. warranty repair shop. I just hope the mechanic respects the boat. Its brand new! I'm worried that he will scratch the gelcoat or the crome fenders, ect.
If it is not vaporlock (I had never heard anyone report it on the 496 before) and it is electrical, did you check the cannon plug at the engine? The really big ass multi conductor plug that connects all of the engine controls and stuff together. Just might want to shove the ends together and make sure it is firmly connected.
Might check the ground conductor on the engine and the battery. If it was loose, it might make the computer shut the engine down. Also how about the fuel pump ground wire? That may be harder to find... Also I would just for giggles replace the fuses even if the look OK. I have had them burn out where you could not see near the tang.
[ September 29, 2003, 08:15 PM: Message edited by: Dr. Eagle ]
Dr Eagle, Thanks for you concerns. The last thing I did before giving up is I took a volt meter with an alarm on it. The buzzer sounds when I have continuity. I stuck the probes in where the fuse went. As the alarm goes off I shook down the whole motor. All the relay and connectors and wiring harnesses. It did go off by shaking one harness, but it had allot of branches on it. Man there are allot of wires and connectors and shit! Anyways, I put a new fuse in, didn't blow, went to the lake, backed it in and nothing. It cranked, same as before, but this time the fuse didn't blow. I'll check the fuse like you said, but its going in to the shop next week
Sorry sounds like I was absolutely no help. You obviously know how to troubleshoot.
I hate phantom problems like this. It is probably a bad connector on the harness or something. If it turns out to be that hopefully they will replace the harness not some kind of gumbah fix.
Anyway, Hope the shop gets this figured out in a hurry.
Finnaly got the boat running. I'm so happy. With no help from the builder I would like to add. Mike @ All Seasons Marine found a problem with a relay and replaced it with an upgraded one. He had mention that the GM/Merc. relays had tendency of crapping out. So their you go! Half of the season wasted in a new boat. Next time buy used?
Yeah, that sucks...I had BOTH engines go one at a time in my Eliminator. The first went before the season on the test drive and the second in the middle of the first season with about 21 hours on it. Trying to get a new engine put in right in the middle of boating season is like pulling teeth. Sooo it was another 5 weeks w/o the boat.
Funny (not ha ha) thing is once you get it "debugged" you will probably have a very reliable engine package.
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