1989 mercruiser 4.3 shut off wont start

[sl8rson]

89 mercruiser alpha one won't start was running great

Hello. In new to this so please bear with me. I have a 1989 celebrity 181 w/mercruiser alpha one drive 6 cylinder i\o engine. Ran great all weekend always stays right up. On my last run I was going about 3/4 throttle to full throttle and all of a sudden the engine stalled and will not start again. I thought maybe it over heated so I waited 15 minutes but still would not start. I got a tow about 45 minutes later tried starting it again but will not start. It turns over and belts move but will not run. Any help us good help much appreciated thank you all

 

[alldodge]

Howdy

Need some more info.
When you move the throttle forward can you see gas squirting into the throat of the carb?
Have you pulled the coil wire and held it close to a ground to see if your getting spark?

 

[sl8rson]

In checking those steps currently. The man at dover marine said to check the emergency shut off switch. He said it sounds like an electrical issue. Unfortunately they can't get it in for 3 weeks so I'm stuck trying to diagnose myself. I'll check spark and fuel and get right back to you. Thank you

 

[sl8rson]

hello. So I'm at the point where Ive found out that I do have gas going into carb, I have compression, But I have no spark what so ever. Ive neen pointed in the directon of checking my cap and rotor but I opened it last night and it don't seem very corroded the plugs could be changed and wires look to be in good codition. I do not have a ton of money, (which is not a good thing for a boat owner lol), so I'm trying to see if anyone has ran into this issue. Again my issue came while I was just about at full throttle abd the engine completely shut off and would not start again. It cranks over just fine and deposits gas into carb but I have no spark to combust fire. Some things Ive been told it could be is the cut off switch which I'm leaning towards it not being the issue seeing that its been shifting fine. Someone else tols me theres a sensor in the rotor that will stop the production of spark? anyone that could help would be very appreciated.
1989 mercruiser alpha one 4.3 thunderbolt ignition
ser# OC611734

 

[sl8rson]

Hello. In new to this so please bear with me. I have a 1989 celebrity 181 w/mercruiser alpha one drive 6 cylinder i\o engine. Ran great all weekend always stays right up. On my last run I was going about 3/4 throttle to full throttle and all of a sudden the engine stalled and will not start again. maybe overheated so I got a tow about 45 minutes later tried starting it again but will not start.

So I'm at the point where Ive found out that I do have gas going into carb, I have compression, But I have no spark what so ever. Ive neen pointed in the directon of checking my cap and rotor but I opened it last night and it don't seem very corroded the plugs could be changed and wires look to be in good codition. I do not have a ton of money, (which is not a good thing for a boat owner lol), so I'm trying to see if anyone has ran into this issue. Again my issue came while I was just about at full throttle abd the engine completely shut off and would not start again. It cranks over just fine and deposits gas into carb but I have no spark to combust fire. Some things Ive been told it could be is the cut off switch which I'm leaning towards it not being the issue seeing that its been shifting fine. Someone else tols me theres a sensor in the rotor that will stop the production of spark?
1989 mercruiser alpha one 4.3 thunderbolt ignition
ser# OC611734

 

[alldodge]

No spark issue is testable. Being you have a TB-IV there is a flowchart for troubleshooting. Follow the chart below exactly and it should tell you exactly what's wrong

 

[Bt Doctur]

Test for 12v at the + side of the coil with the key on
if no voltage run a jumper from the + battery to the + side of the coil and try starting, report results

A few reasons no 12v to the coil, ign module in dist, main ign module, bad tach ,broken dist shaft/gear/rotor..the list is endless.

 

[alldodge]

Ya got two threads going on
http://forums.iboats.com/forum/engi...uiser-alpha-one-won-t-start-was-running-great

 

[Bondo]

Ya got two threads going on
http://forums.iboats.com/forum/engi...uiser-alpha-one-won-t-start-was-running-great

Nope,.... Not anymore,......

 

[sl8rson]

sorry for messages I do not know how the forums work and as for two forums goin I thought I had to check in different area under different title description. Either way I want to thank everyone for helping me out.really I wish I could just put it in the shop but they have a 4 week waiting list and I need my boat to run for next weekend lol. thank you all.
I've tested power going into ,manifold mounted ign. module and I have power going in but not coming out. Is this a good sign the module needs to be replaced? I was leaning towards the coil but I have power coming out of the coil going into the module but no power going from module to distributer. I have no voltmeter I just have a test light.(doing what I can with what I got lol)
Any info is good info I appreciate anything you can share to help me. Thank you very much.

 

[alldodge]

I have no voltmeter I just have a test light

You really need a volt meter to test using the flow chart above. You can pick up a voltmeter for real cheap at walmart or other auto store, doesn't have to be a high dollar one

 

[sl8rson]

thanks I just found that out I didn't know they wre cheap we bought one at work buy it was 200

 

[sl8rson]

I cannot wait until I can share my boat experience to help others on this forum its really helped me. Ill respond tomorrow after I do the checklist with the voltmeter

 

[sl8rson]

So I did the flow chart test everything lead me to changing the ignition control module. In leaning towards going to Delco est, does anyone know where to get one?

 

[alldodge]

The system can be found at several sites including ebay. Search for "delco est marine distributor" and they will come up.

 

[DaboatnutinWA]

Before you throw down your cash on a new ignition system......pull the distributor and check the gear at the bottom. It might be chewed up. My 4.3L did the same thing as yours.It was running beautifully at 3/4 throttle and just suddenly died. As for the cause of the distributor gear getting chewed up Im told its a softer metal and its designed to do that. The cam is hardened so it will survive. As for mine, its all better after the incident. I bought a new GM distributor gear (30 bucks), drained the old oil, re-installed distributor, put in new oil with new filter, got it started, timed it and it runs like a Swiss watch. This all happened at the end of the 2014 boating season. Ran great for the 2015 season despite having fuel delivery issues.

 

[sl8rson]

Does anyone know how to disconnect the shift interrupter? I'm about to buy a module but reading other posts people try this and succeed

 

[achris]

To disconnect the shift interrupt switch, just remove the white/green wire going to the switch, at the terminal block. Before buy a new module, just disconnect the gray wire going to the engine harness (removes the tacho from the system) to make sure that the tacho isn't causing the problem. Here's a circuit diagram of your ignition system. (this one covers the V8 as well, but the rest of the system is exactly the same).

 

[sl8rson]

So if I could update. ..I found the power to the helm. Just a wire that plugged into the fuse panel came undone probably from moving things around to try to get spark. Still no spark. I've ordered new coil new ecm harness, plug wires cap and rotor, pretty much new tune up hoping this will help but I'm still not too sure. I'm counting on the harness seeing as that's what the thunderbolt test tells me to do right before the module [which I've changed].I'm almost sure I disconnected the shift interrupter but still nothing. I did have a second ground wire coming off the module I can't seem to find where that goes there is the original one on the bottom of the harness that is hooked up but this other wire is on top not hooked up coming from the bolt on the triangular plate mount. Also I found a green wire coming from top of fuel tank that's not connected to anything. There's 3 wires,black orange and green coming from the tank. Could anyone tell me what the green one is for? I don't remember unhooking this wire but maybe it came off something. There was a wire that was not hooked up in the front of the engine connected to what I think is the water temp sensor? There was 2 cream colored wires hooked to a brass fitting into the areas where the 4 water hoses mount into, only one was connected that was like that when I got the boat. When I check power to that wire I'm getting a trace amount [like 6-8 volts]which I find perplexing that it wouldn't be either 12v or no volt. Anyways if you don't get too confused from my update and could maybe share some insight into my, seems like never ending battle to get spark, I would be much much appreciated. Thank you. Also how do I close my other threads so I'm complying with the forum rules. I love this forum without you all I would be paying 100 bucks an hour to get my boat fixed which is not feasible right now. Thanks again

 

[alldodge]

So if I could update. ..I found the power to the helm. Just a wire that plugged into the fuse panel came undone probably from moving things around to try to get spark. Still no spark. I've ordered new coil new ecm harness, plug wires cap and rotor, pretty much new tune up hoping this will help but I'm still not too sure. I'm counting on the harness seeing as that's what the thunderbolt test tells me to do right before the module [which I've changed].I'm almost sure I disconnected the shift interrupter but still nothing. I did have a second ground wire coming off the module I can't seem to find where that goes there is the original one on the bottom of the harness that is hooked up but this other wire is on top not hooked up coming from the bolt on the triangular plate mount. Also I found a green wire coming from top of fuel tank that's not connected to anything. There's 3 wires,black orange and green coming from the tank. Could anyone tell me what the green one is for?

The green wire is an internal ground and unless the manufacture installed a ground buss bar they will not be used. Black is system ground and the orange goes to your gas gauge.

I don't remember unhooking this wire but maybe it came off something. There was a wire that was not hooked up in the front of the engine connected to what I think is the water temp sensor? There was 2 cream colored wires hooked to a brass fitting into the areas where the 4 water hoses mount into, only one was connected that was like that when I got the boat. When I check power to that wire I'm getting a trace amount [like 6-8 volts]which I find perplexing that it wouldn't be either 12v or no volt. Anyways if you don't get too confused from my update and could maybe share some insight into my, seems like never ending battle to get spark, I would be much much appreciated. Thank you.

The cream color should be something like the temp sender, don't know why there are two of them on your year boat. Can you take a pic and post?

Also how do I close my other threads so I'm complying with the forum rules. I love this forum without you all I would be paying 100 bucks an hour to get my boat fixed which is not feasible right now. Thanks again

Don't bother with old threads. The rules are they do dormant on their own after so many days. If you ever need to reopen a thread you can so long as you were the one to start it. Go to the rules thread and read them, they will explanatory