Wiring help needed

[1997StingRay190]

So I'm getting very close to putting the new engine in the boat and was hoping I could get some help with a few wires I"m no 100% certain on. The first...

Like the caption says, white/red and white/blue off of ignition module and black. Where do these go? Are they only used for diagnostics maybe?

 

[1997StingRay190]

Re: Wiring help needed

Next is

What is that? Knock sensor maybe? Does it need a wire going to it? If so is it just a ground or something else?

 

[1997StingRay190]

Re: Wiring help needed

Off the old engine

Looks like oil pressure sending unit maybe? And what about the big round deal with the stud on it? Does it require any wire?

 

[1997StingRay190]

Re: Wiring help needed

And the two off the distributor, do I connect these to the two that are right there on the wiring harness? If so which colors go where?

 

[1997StingRay190]

Re: Wiring help needed

What about the top 3 wires.

How many need to go to the carb? The old carb only had 1 going to it I think. The ones I'm talking about are the two blacks and one purple at the top.

BTW, the new carb is the edelbrock 600 CFM marine carb

 

[Rocky_Road]

Re: Wiring help needed

Off the old engine

Looks like oil pressure sending unit maybe? And what about the big round deal with the stud on it? Does it require any wire?

The 'big' round one is the oil pressure sending unit (to guage)...and the usual wire to the stud would be light blue. The unit itself provides the ground, when screwed into the engine block.

The smaller one looks like what used to be the oil pressure switch (to alarm system)...the rubber cover seems to be long gone. Its' wire is usually tan/blue.

 

[1997StingRay190]

Re: Wiring help needed

The last one.

I know the two with the zip tie go to the drive oil reservoir, is the third one
(purple/white stripe) used? If so where???

Many... many thanks to anyone who helps with this!!!
The wiring harness is from a 97 mercruiser 4.3, the block and internals are like a 92 or something like that.

 

[Rocky_Road]

Re: Wiring help needed

Next is

What is that? Knock sensor maybe? Does it need a wire going to it? If so is it just a ground or something else?

Oil pressure sending unit (to guage)...wire should be light blue.

 

[Rocky_Road]

Re: Wiring help needed

What about the top 3 wires.

How many need to go to the carb? The old carb only had 1 going to it I think. The ones I'm talking about are the two blacks and one purple at the top.

BTW, the new carb is the edelbrock 600 CFM marine carb

The electric choke uses a purple, and a black, wire.

 

[boatguya1]

Re: Wiring help needed

The last one.

I know the two with the zip tie go to the drive oil reservoir, is the third one
(purple/white stripe) used? If so where???

Many... many thanks to anyone who helps with this!!!
The wiring harness is from a 97 mercruiser 4.3, the block and internals are like a 92 or something like that.

Purple and white looks like the timing lead. It is grounded to set the timing to no electronic advance for setting timing and adjusting idle mixture. Should be capped when not in use.

James

 

[Rocky_Road]

Re: Wiring help needed

The last one.

I know the two with the zip tie go to the drive oil reservoir, is the third one
(purple/white stripe) used? If so where???

Many... many thanks to anyone who helps with this!!!
The wiring harness is from a 97 mercruiser 4.3, the block and internals are like a 92 or something like that.

The purple/white wire is usually used to place the engine into base timing mode.

You would ground this wire to the block...and set your base timing. Don't forget to unground, when done!

 

[boatguya1]

Re: Wiring help needed

So I'm getting very close to putting the new engine in the boat and was hoping I could get some help with a few wires I"m no 100% certain on. The first...

Like the caption says, white/red and white/blue off of ignition module and black. Where do these go? Are they only used for diagnostics maybe?

Black to ground. Rd/wht and Grn/wht to same fro distributor.

James

 

[boatguya1]

Re: Wiring help needed

And the two off the distributor, do I connect these to the two that are right there on the wiring harness? If so which colors go where?

Wht/grn and Wht/red covered above. The other two I think are the trim sender leads for the trim gauge, could be wrong on this one.

James

 

[1997StingRay190]

Re: Wiring help needed

Wow, that was quick. THANKS GUYS!!!!!

Anyone able to confirm what the two wires on the harness are that are right next to the two coming off the distributor?

So to set the timing, just ground that purple wire, set to 10 degrees BTDC?

If that is the proper procedure, do I need anything other than a regular old timing gun and to ground the purple wire mentioned above? The manual says you need some special timing gun and/or a special mercruiser something or other tool.

Once again. Thank you guys!

 

[Rocky_Road]

Re: Wiring help needed

Wow, that was quick. THANKS GUYS!!!!!

Anyone able to confirm what the two wires on the harness are that are right next to the two coming off the distributor?

So to set the timing, just ground that purple wire, set to 10 degrees BTDC?

If that is the proper procedure, do I need anything other than a regular old timing gun and to ground the purple wire mentioned above? The manual says you need some special timing gun and/or a special mercruiser something or other tool.

Once again. Thank you guys!

You are the Thunderbolt ignition...and carbed. Right?

Not EFI....

If so, then grounding the wire is what you do. The special scan tool is used on the EFI setup, to set the ECM into service mode. An advance timing light is easiest to work with...and can be used to check your spark advance after you have set the base timing. Not knowing what 'marks' are on your balancer, it could be that an advance timing light is required. You need to look at the marks....

 

[1997StingRay190]

Re: Wiring help needed

Mine is non EFI, its carb'd, dist/cap wires.

I've never set timing before so please bear with me, but the person who put the distributor in says its definitely in the right position.

Is 10 Deg. BTDC the correct timing for the cerebrated 4.3's?

My setup has the timing tab which goes from 10 deg BTFD to 0 to 10 deg ATDC

Then the harmonic balancer has a (just 1) line in it. Is that all we will need to set the timing? The person helping me actually knows what they are doing, but am I going to need anything else other than the timing gun?

Do I really need a shop tach or can I just go off of the one in the inst. cluster?

Any tips, cautions, or anything else?

Thanks again.
Sean

 

[boatguya1]

Re: Wiring help needed

If you won't always run 89 or higher octane fuel I'd set the timing to 8* instead of 10* BTDC.

James

 

[Rocky_Road]

Re: Wiring help needed

Mine is non EFI, its carb'd, dist/cap wires.

I've never set timing before so please bear with me, but the person who put the distributor in says its definitely in the right position.

Is 10 Deg. BTDC the correct timing for the cerebrated 4.3's?

My setup has the timing tab which goes from 10 deg BTFD to 0 to 10 deg ATDC

Then the harmonic balancer has a (just 1) line in it. Is that all we will need to set the timing? The person helping me actually knows what they are doing, but am I going to need anything else other than the timing gun?

Do I really need a shop tach or can I just go off of the one in the inst. cluster?

Any tips, cautions, or anything else?

Thanks again.
Sean

That should be all that you will need.

The problem with using the boat tach is obvious...it is not as accurate as a shop tach...especially in the lower scales. To be precise, the engine should be running at the specified idle rpms. Use your best judgement, on this one...maybe you know someone that has an inductive timing/tach light, that you can borrow?

Does your engine have the shift interupt switch...to help with gear shifts? If so...you may need to bypass it to set the base timing. Go to the Adults Only section, and read the manual on your engine.

 

[1997StingRay190]

Re: Wiring help needed

Just want to confirm one more time here...

I have the Thunderbolt 4 ignition. I ground the purple white stiped wire to set base timing?

in the manual, it never mentions this for thunderbolt 4, only thunderbolt 5 - and thats why I'm asking again. Sorry to be a PITA, but I just want to make sure I'm getting this done right.

Thanks,
Sean

 

[wca_tim]

Re: Wiring help needed

no, you just set it at the propper rpm with a thunderbolt 4.