new boater, timing questions.

[LivALittle]

Hey, I have read a ton of post about my issue, but non have been clear. i'm new to boating and have a 92 merc 3.0L LX I/O. It has EST ignition. I have set base timing to -1 degree. When i check timing advance at 2-3K it goes to 11 degrees, at 4K it only goes to 14 degrees. Spec is 23 degrees. I was told my Ignition module is bad. I have ordered one. Now my problem is, the shift interupt switch. I have two post at the switch. One to the right has 2 white wires going to it and connected at same post. The left side has a black wire going to it and another black wire not connected and just hanging near by. Is this the correct setup? also should i even touch my shift interupt wiring after replacing my "faulty" Ignition module before rechecking the timing advance? thanks!!

 

[Don S]

Re: new boater, timing questions.

I have two post at the switch. One to the right has 2 white wires going to it and connected at same post. The left side has a black wire going to it and another black wire not connected and just hanging near by.

Could you post a picture of what you are seeing?

Here is a file on timing, the second page has the wiring diagram for your engine.

View attachment 3.0 EST timing.pdf

 

[LivALittle]

Re: new boater, timing questions.

heres a pic, sry it took so long. tell me what u think, if this is normal. what would the open black wire be? thanks.

 

[jopes]

Re: new boater, timing questions.

I would say that black wire is supposed to be on the left screw. black wire to black wire. The switch could be bad and the previous owner disconnected one of the wires?

 

[Don S]

Re: new boater, timing questions.

Ok, I now see what happened. Your engine originally had a points distributor and that setup with the terminal block to ground is to ground out the ignition to activate the shift interrupt system.
Here is the wiring diagram for the points system. View attachment #13 GM 4 cyl 90-97 253.pdf

Your system should be wired as shown in the other wiring diagram I posted earlier. it doesn't ground out the EST distributor, you put power to the distributor not ground it.

Looks like you are going to be doing some rewiring, You can not use that terminal block and you have to put power as shown in the EST wiring diagram.

 

[LivALittle]

Re: new boater, timing questions.

Thanks guys! so with my wiring outta wack for the shift interupt switch, what issues should i have with the way it wired as of now?

 

[Don S]

Re: new boater, timing questions.

You won't have a shift interrupt system. Serious problems getting it out of gear. Will probably damage the shift cable in short order. Damage to gears and clutch dogs in lower unit.

Best to wire it exactly like the wiring diagram. including the bullet connectors. You have to be able to jumper the wires to set the timing.
DO NOT use that terminal block for anything. It's grounded and will not work.

 

[LivALittle]

Re: new boater, timing questions.

thanks don. i thought it seemed alittle tight getting out of gear when in the water. I will wire it as it is in the first diagram. My timing shunt tool has the white wires connected in a loop and a power wire, i will plug that into the distributer then just cut those white wires and put connecters on the ends so i f i need to set timing i can. Then run the power wire from the shunt tool to the left side of the shift switch. The other side of the switch looks like it goes right to power. Does this sound correct? and if i'm correct when you place it in gear that switch is activated thus applying power to the distributer "white/green" wire killing spark for a sec until your in gear? sry if i confused you, its much easyier to fix if i understand how it works.

 

[Don S]

Re: new boater, timing questions.

The other side of the switch looks like it goes right to power. Does this sound correct? and if i'm correct when you place it in gear that switch is activated thus applying power to the distributer "white/green" wire killing spark for a sec until your in gear?

That's it. The EST uses power to cause the hesitation, not ground like the points system used.

 

[LivALittle]

Re: new boater, timing questions.

alright! looks like i'm on the correct path. So after all this wiring i can follow the book now to set the timing. Thanks Don!

P.S: my other issue was my timing advance not advancing past 14 degrees at 4K, ill keep this thread updated after i install my new ignition module. thanks again!

 

[Don S]

Re: new boater, timing questions.

See if this helps

View attachment #26 3.0 98-newer 233.pdf

 

[LivALittle]

Re: new boater, timing questions.

Well im still having an issue after installing a new Ignition Module. I beleive its a shift inteript wire issue because i cant get into base timing mode now. With the shift interupt completly unhooked. My motor is the 3.0 LX so it had the ddis system. Well looking at the diagram that don had posted i wired the interupt switch just as it is in the schematic. Engine warm and running i use my finger and manual depress the switch. Nothing happens. I discount the switch and ohm across both sides and its open when not depressed and .03 ohms when pressed. Do i need to be looking at a different wiring diagram when going from a ddis to est delco ignition? ill do some more searching on the forum to see if i can find some info. thanks

 

[Rob the weekend warrior]

Re: new boater, timing questions.

okay, I dont have the boat or the engine you have but the theory is still the same with all the EST dizzys. you supply power to the shunt to get your initial timing-which just so happens to retard your timing and make your engine "stumble". AND you have a switch that is "on" when your outdrive is getting in or out of gear! presto! simply use the switch to supply your EST with power, fooling the motor to believe that you are trying to time it every time you go into gear, retarding the timing. SO find ignition power, run it to one wire from the switch and run the other wire from the switch direct to the timing shunt. Take your shift interruptor and sell it on ebay, and now you can take a timing light and test out your setup to see how it works. I have a OMC 5.0 and this is butter smooth. This is basically how the wiring diagram has it on the top of the page.

The ONLY problem is that in the event that the shift interruptor switch ever becomes stuck in the closed (on) position due to stiff/maladjusted linkage there is no secondary (override switch) in the loop so you will be stuck in retard mode. I countered this by adding a bullet connector in this wiring and protecting it all by a SMALL 3A fuse, so in the event that I am out on the water, with my linkage out of whack, motor running badly I can just disconnect this to get back to the dock. the fuse is small so that in the event that between me disconnecting the circuit and me getting to the dock this grounds itself out on the intake or something and blows a fuse it blows the small 3A fuse and not the motor 20A or 40A leaving me stranded.