1989 four winns liberator 350 engine no spark!

[JesseNagy]

As the tittle says I have a 1989 four winns liberator with a mercruiser 350 engine. I recently acquired it not running. Someone previously rebuilt the engine and did not finish wiring it up completely. I rewired the complete ignition side to the best of my ability from what I can come up with online. So my question is.

I’m getting power into/out of the coil going to the top of the distributor and through the cap on the inside. I have 12v power going to my red/white wire on the distributor. Other wire is green and white. I did a test I seen online about putting a spark gap tester between coil and cap, and removing green/white wire and grounding it with key on and my tester lit up. The test then said my ignition spark sensor in my distributor was bad. I swapped it with another one I received with the boat (unsure of its condition) and repeated the test and got the same results. And still no fire by turning the motor over. Before I go buy a new one is there any other test I can do?
Any help is appreciated!

 

[dubs283]

voltmeter red lead to wht/red lead coming from ignition module black meter lead to good ground, key on should see 12 (+) volts

with meter still attached hold the wht/grn wire from module to good ground and see if voltage drops momentarily then returns to 12 (+) volts - this will tell you the module is good and you need to replace the ignition sensor in the distributor

best advice is to use a quicksilver brand new sensor (fully potted/sealed) - had issues with aftermarket sensors

 

[JesseNagy]

Do you have any experience with switching over to the est electronic ignition distributor and coil? And doing away with the timing box and current setup I have? Thinking about going this route.

 

[dubs283]

you can do as you please but if all you need is an ignition sensor there's no reason to abate the thunderbolt system. it's pretty much the best stock marine electronic ignition system available

 

[Scott06]

you can do as you please but if all you need is an ignition sensor there's no reason to abate the thunderbolt system. it's pretty much the best stock marine electronic ignition system available

Agreed on this one TB has the hottest spark ive ever seen.
likely you replaced the sensor with a sensor someone removed before.…

 

[JesseNagy]

Agreed on this one TB has the hottest spark ive ever seen.
likely you replaced the sensor with a sensor someone removed before.

 

[JesseNagy]

Would either of y’all happen to know a part # for the ignition sensor? I’ve tried to find it but couldn’t come up with anything. I will attach a picture of what mine looks like.

 

[poconojoe]

Can someone post up that TB troubleshoot chart? That should help.

 

[JesseNagy]

Can someone post up that TB troubleshoot chart? That should help.

Is this what your referring to?

 

[Scott06]

Would either of y’all happen to know a part # for the ignition sensor? I’ve tried to find it but couldn’t come up with anything. I will attach a picture of what mine looks like.

87-892150Q02 is the quicksilver part number
18-5116-1 is the sierra aftermarket part number

 

[poconojoe]

Would either of y’all happen to know a part # for the ignition sensor? I’ve tried to find it but couldn’t come up with anything. I will attach a picture of what mine looks like.

Idk..I couldn't give you any part numbers.

Run through the diagnostic flow chart before you start throwing parts at it.

That being said
I replaced mine a few years ago. If I recall it was only about $40. I think mine may have looked a little different.
My original one was not a sealed unit. It was just an open circuit board! It was all corroded.
The new one is a sealed unit.

 

[poconojoe]

Is this what your referring to?

BINGO!
Very helpful chart. I used it a few years ago to track down the very same ignition module under the distributor cap.

 

[dubs283]

18-5116-1 is the sierra aftermarket part number

i would strongly recommend avoiding this one, have had many fail/not operate properly in the past...

 

[poconojoe]

Mine is a 4.3 carbed engine from 2003.

I just looked up my order history and the ignition module I bought is made by Mallory, part # 9-29804. I paid $46 in 2018.

I don't know if your engine uses the same one, but I thought I'd post it for reference. If it doesn't help you, then it might help someone else.

 

[JesseNagy]

Idk..I couldn't give you any part numbers.

Run through the diagnostic flow chart before you start throwing parts at it.

That being said
I replaced mine a few years ago. If I recall it was only about $40. I think mine may have looked a little different.
My original one was not a sealed unit. It was just an open circuit board! It was all corroded.
The new one is a sealed unit.

That’s what Ive been trying to figure out, mine is the open circuit board style as everything I’m seeing online is a sealed unit. So that is what replaces my old style?

 

[poconojoe]

That’s what Ive been trying to figure out, mine is the open circuit board style as everything I’m seeing online is a sealed unit. So that is what replaces my old style?

Absolutely. The replacement is sealed. You can't see the circuit board.
The Mallory unit worked great for my 2003 (carburetor) 4.3L, Tb-V

 

[JesseNagy]

Just a little update**
I replaced the Ignition sensor with the quick silver part mentioned above about a week ago. Boat started up and ran great. Well yesterday I decided to mess with the timing and I left the boat sit over night with the battery hooked up for the first time since I’ve had it, came out this morning and went to start it and no spark again, did the same test and it’s showing the ignition sensor is bad again. Any clue on what could’ve caused it? Something staying on that could have fried it?

 

[Bondo]

Just a little update**
I replaced the Ignition sensor with the quick silver part mentioned above about a week ago. Boat started up and ran great. Well yesterday I decided to mess with the timing and I left the boat sit over night with the battery hooked up for the first time since I’ve had it, came out this morning and went to start it and no spark again, did the same test and it’s showing the ignition sensor is bad again. Any clue on what could’ve caused it? Something staying on that could have fried it?

Ayuh,..... Welcome Aboard,...... Was the key switch left "on" too,..???