Basket case 4.3, gonna have some questions

[Rick Stephens]

Here's the older wiring diagram:
http://boatinfo.no/lib/mercruiser/manuals/mercruiser7.html#/278

 

[achris]

http://forums.iboats.com/forum/engi...-mercruiser-thunderbolt-ignition-systems-work

This might help you understand how the ignition system works, and thus how the wiring should be.

Chris...

 

[Bumperlt12]

Thanks you guys. Now that I've had a minute to sit down and look at all the info I see what I did. I'll fix it tomorrow.

I just need to figure what white/blue is which I'll do when I'm done posting this.

Now that engine is in, I can think about the fuel system. My fuel pump block off didnt come yet. I purchased a oil pressure switch but its not here yet. Im concerned about the fuel pump thats installed, see attached.



No markings on it other than "edelbrock". And nailed in. PO was an idiot. I assume this is not a well known pump for marine applications.

Also picture of gantry.

 

[Rick Stephens]

I was wondering about that white/blu too. Nothing on the schematic. Must be a different system, maybe trim or trailer sensor.. I gotta go weld up a combine early, I get back early enuf I’ll loook around.

 

[Bumperlt12]

I pulled this from manual 7. Says 1989+ on this diagram.

The black wire near the electric choke grounds to the choke itself. Solved.

The tan/blu looks to be for a temp switch. There's a bundled tan/blu at the back of near oil pressure sender, presumably for an oil pressure switch per this diagram. Solved.

Now, back to the interupt switch. If i go by the diagram here, it looks like one of my wht/grn goes to distributor, the other to terminal block, as does the black. For some reason my gry at terminal block is wht/grn. Whatever. Solved.

 

[nola mike]

You got it. The tan/blu is for the oil pressure alarm, which is optional. I also have wht/grn at the shift interrupt. '89 model year. That black going with the grn/wht should still go to the terminal block at the switch with a different black (running with a purple wire) running to the choke. All grounds though and the terminal block is grounded, so probably doesn't matter much

 

[Bumperlt12]

Seeing how I have an electric fuel pump, do I just cap the nipple at the carb?

Does anyone know the size of the fuel inlet? I want to buy a barb fitting but I forgot to figure out its size?




Fuel pump... is 2-3.5 psi enough??

 

[Rick Stephens]

Yup, just cap it with a rubber nipple. My whole system is 3/8”. Hoses and tubing. Yours may be different. Read it off one of the hoses. Make sure you use marine hose!

 

[achris]

...Fuel pump... is 2-3.5 psi enough??

Pressure isn't as important as flow, and the flow you have is PLENTY! Those 4.3s at full noise drink about 60 litres per hour...

Chris....

 

[Bumperlt12]

I like the idea of having an audible alarm if temp is too high or oil pressure is too low. Going to look into adding a used oem optional system.

Cuddy heater. Hot water goes out intake manifold, or in my case I think back of thermostat housing where there's currently a plug?


Confirm / deny... anyone?

 

[Rick Stephens]

I can't confirm, but I thought it was the other way around...... see if I can find.

 

[achris]

Cuddy heater. Hot water goes out intake manifold, or in my case I think back of thermostat housing where there's currently a plug?

Hose coming back from heater going into circulation pump, on the side.

Confirm / deny... anyone?

Confirm, correct. That plug on the pump is on the suction side.

Chris.....

 

[Rick Stephens]

Confirm, correct. That plug on the pump is on the suction side.

Chris.....

Thanks for fixing. That makes sense.

 

[Bumperlt12]

Thanks for all the help yall

Tomorrow is startup day. Are there any must-dos before start up? I bought a oil primer that goes down the distributor hole and spins the oil pump. I read to take off valve covers and wait for oil to seep out. Thing is, the starboard valve cover requires a lot of effort to remove. I might just losen enough so I can get a peak in.

So, prime oil system. Should I add anything to list before start up?

 

[Bumperlt12]

Dipstick tube replacement

well I got my new motor in and was doing a final punch and noticed my dipstick tube still on the shelf. Dammit.

Engine is completely reassembled and back in boat. how many steps backwards do I have to go to get it in?? Its the full tube including part that goes into oil pan.

 

[Bt Doctur]

If the plug has been removed simply insert it into the block opening

 

[nola mike]

What engine?

 

[Bumperlt12]

I dont know what I was thinking ill continue this in my existing thread. Please delete!

 

[GA_Boater]

I dont know what I was thinking ill continue this in my existing thread. Please delete!

Moved the other thread into this one. We all go oooops on occasion. :smile:

 

[Bumperlt12]

Just got home from making more progress.

Wiring the electric fuel pump has me rattled. So im here again needing someone to hold my hand. I screenshotted multiple diagrams and explanations, but it seems there's multiple ways to get it done.

Oil pressure switch is a Standard Motor Products PS-64. Terminals are I, S, P.

I have a wire attached to the correct post on the starter (sends power while starter is operating), but does it go straight to the pump as well or to the oil pressure switch? I read both ways. Although my mind is mushy about this at this. I looked up the pump's amperage at full operation and it said 1A. So im going to run power through the switch and not use a relay. Isn't that the oem method anyhow?

"I" is ignition, key on. Tied it in with electric choke wire.

"P" goes to electric pump

"S" goes to starter

True/false?

AND

I forgot to put the dipstick in. Looks like manifold has to come off to do it? Then I have to press it in somehow? I guess that valve cover can come off for oil priming now.