Re: 4.3l automotive in a boat??
mylesm260, I would like to see some pic's of that if you have some. I could see where that would be safer than the marine setup, its like a sealed system. I would thing its a lot safer than the carb's that are used on sooo many boats. I do have one of these engines. It came out of 2001 Chevy blazer, with only 32,000 miles. I just have to figure out the wireing issues. the o2 sensores are the least of the wories. You just need a few resistors too handle that, let me know if you have any pic!!
Yup, I don't mine snapping some pics....
Here's some of what I learned doing this swap...
#1. The blazer and Astro keep their ECU's under the hood. The connectors and ECU itself is completly water-poof and marine worthy already.
#2 The fuel system from the installer's point of view is a simple in and out on the top of the manifold, plus you can salvage the stainless fuel lines out of the doner vehicle, and use them for the connection. I had high PSI hydrolic hose cripped to the factory stainless lines..... Hydrolic fluid is pretty much one of the most corosive things you could think of... those hoses are tough as holy hell.
So I supplied the engine with high pressure fuel, connected the factory wiring harness, supplied +12 to the correct pins on the ECU, and cranked it... it started right up.
Then all I Did was re-route and shorten the wiring harness. Do it one wire at a time, and you won't have to worry too much about the pin out. Solder and heat shrink tubing are your friend. Then make sure you tape and re-cover the harness in it's plastic shroud. Make sure there is no rubbing, or you could get a spark.
I ran a relay in series with the +12 to the ignition coil for the shift interupt. You put tension on the shift cable, the relay triggers, the coil no longer gets +12, the engine stutters and your shift completes. Works perfectly.
And of course as we ALL know...
Marine starter
Marine Alternator
Marine Dizzy cap (my OEM one looked sealed, so I didn't bother looking, but I feel I have to mention this)
Marine casting plugs ("frost" plugs)
Marine head gaskets & Marine water pump (didn't bother with this, waiting for them to leak, my boat never sees salt water, been two seasons so far, no problems yet)
and yes, while it is not marine rated, I believe it to be way safer than a carb setup. Just don't be stupid with the actual fuel lines and pump either...
A lot of my fuel fittings were NPT.. I discovered that gas eats teflon tape... Get yourself some thread sealant... from the same guys who make locktight
Why do you think you need a resistor if you have no o2 sensors? o2 sensors fail ALL the time. you can pretty much bet that unless you're in a state that does emision testing, 75% of the 4.3's on the road are already running with blown o2 sensors. Just leave those circuits 100% open. Your engine will still run perfectly, you will just loose the ability to go into closed loop mode. Since no boat made before 2005 or so has closed loop anyway, your not going to be missing much.
The EFI system without the o2 sensors is still WAY WAY more accurate than any carb. These are MAF systems. Very accurate, even without o2 feedback.
Only REAL thing you will notice is if you plug an OBD2 code reader into the harness, the computer will ***** about the o2 sensors and heaters missing, that's all.
