140 hp mercruiser starting issues, troubleshooting performed. Lost!

[Motodox]

Ok im starting a new thread to for clarity on my issue, I've also performed multiply troubleshooting and still no luck, I'm lost at this point and really need to figure this out! Thanks in advance.

We have 1986 Rinker v170 open bow boat with. 3.0l 140hp mercruiser 4cyl with alpha1 out drive.
Been converted to electronic ignition over a year ago with the flame thrower coil and the same brand ignitor.

Boat ran perfect all day then died on water and will not restart!

Troubleshooting performed :
Compression tested all cylinder I'm 135 psi or more
Checked timming at TDC on compression stroke #1 cyl. Notch on crank bell is sitting on 0 and under cap the rotor is pointing right at #1 cylinder wire. So timing should be good correct (as far as I know)
I have 7.89 volts at the coil touching the + and -
I actually do see a spark on the plug just doesn't seem like much
With the air breather off I can pump the throttle and visually see two streams of fuel dumping into carb. Plugs even pull out and smell of fuel and are wet after several attempts to start.
Replaced plugs mr43t delcos with .035 gap
I checked the shift interrupt and it seems to be sitting in the right position and it grounds out when you press it in.
I have a good strong battery sitting in a tender and fresh fuel
Everything works on the boat still, gauges lights pumps blower etc. just won't fire and run.


At this point I don't know what else to do, I have spark fuel air compression and timing has been checked. What am I missing!?!? This motor has ran great for me all year! Might I add I've changed fuel filter and cleaned screen in carb this year as well.

Could I just have too weak of spark, should I replace the electronic ignition kit again coil and ignitor, should I replace wires cap and rotor even tho I do have some sort of spark?

 

[wahlejim]

When is the last time you changed the cap, rotor, and wires?

 

[biggjimm]

Did you check it with the spark gap checker? Have you tried the other suggestions posted in the other thread? It might be the module but I wouldn't just put one in it without at least checking the spark. It sounds to me like your spark is weak but until it's checked, who knows???

 

[Motodox]

I have never changed the cap rotor and wires personally. They look older yet oem but the cap and rotor underneath look good no corrosion.

I have a spark plug tester that u can set the gap and visually see the spark, what gap should I set it too?

And I have definitely seen spark at the plugs but doesn't seem very strong or seems to possibly die out.

Question can I turn motor over and check for spark without the muffs hooked up? While checkin all the spark plug wires

 

[wahlejim]

For me, a tune-up consists of changing out wires, rotors, and caps, regardless of what they look like. I change those out every 2-3 years. Simple, cheap, and provides piece of mind. You can get kits for under $60 online.

 

[Rick Stephens]

On the other hand, cap, rotor and wires won't usually stop a good running motor dead in its tracks. That would be more in the realm of a coil or the electronic ignition.

 

[flipbro]

A bad cap rotor or wires will cause your coil to heat up and fail! Did you check the ohms of the coil yet? And yes you can pull the plugs and crank it over to check spark. Hows the carbon electrode look in the center of the distributer cap they will burn up and stop a good running engine in its tracks!

 

[Rick Stephens]

A bad cap rotor or wires will cause your coil to heat up and fail! Did you check the ohms of the coil yet? And yes you can pull the plugs and crank it over to check spark. Hows the carbon electrode look in the center of the distributer cap they will burn up and stop a good running engine in its tracks!

I can buy that.

 

[airshot]

Need a bright blue spark.....if spark is orange in color then it is weak. Appears you have a spark issue from your description.

 

[Motodox]

Ok I have the electronic ignition after work today I tested the ignitor and it tested good. I have the pertronix ignition kit, which includes the 3 ohm coil. I tested the coil I have continuity and it reads about 3.5 ohms - to + post. So I called the guys who make this ignition kit and they said that's all normal. So my coil and ignitor must be good.

As for the plug wires cap and rotor you really think those could cause my boat to just die from running perfect and not restart? I did a ohm reading on the short 5 in plug wire and it was 4500 ohms or 4.5 k ohms is what my volt meter read.

 

[Motodox]

Can you guys see this picture? Hoping the upload works

This is he bottom side of cap

 

[Motodox]

 

[AgnotGt]

Sorry to hear 'bout your problems. Just adding my 2c's.

Have you taken the coil lead out of the cap and held it just off a ground, 1/8 in or so, to see if you have spark?

With the cap off does the rotor turn when cranking the engine?

Does the rotor look complete?

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[Motodox]

Sorry to hear 'bout your problems. Just adding my 2c's.

Have you taken the coil lead out of the cap and held it just off a ground, 1/8 in or so, to see if you have spark?

With the cap off does the rotor turn when cranking the engine?

Does the rotor look complete?

.
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Yes I have pulled the coil wire and I have strong fire from the coil wire, plugs are not near as strong of fire.

I have pulled cap and cranked over and rotor button does spin clockwise. And yes my rotor button looks exactly like that.

I just ordered new cap and rotor and wires, oem. Can't see it being the problem but I sure as hell hope so!

Still just done understand how it's not firing!!!

 

[biggjimm]

Did you test the spark at the coil & the spark plugs with the gap tester? What were the results? With it just shutting off like you describe, and you've got good fuel getting to the carburetor, it'd almost have to be ignition related.

It could definitely be the cap keeping it from starting but I can't see it just shutting off because of a faulty cap without some other symptoms. Spitting & sputtering or something.

If the spark at the plugs is good & happening at the correct time then you've got to move on to something else. If you've got good compression, good clean fuel getting to the combustion chambers & good spark at the correct time, it has to run. At the very least, it should try to run. Let us know how it goes with the new cap & stuff & how that spark tests out.

I just looked at my spark gap tool & it's about 7/16" it shows for electronic ignition as far as how far of a gap to set it at. Good luck. Jim.

 

[jaa241]

Which pertronix unit did u purchase or is on it. Pertronix 1 or 2. If it is one most likely there is an issue with the pertronix. I can clarify if why, if u have pertronix 1. I had same issue and purchased pertronix 2 and all starting and running issue were gone.

 

[Scott Danforth]

the cap has carbon arc tracing in it from point to point. replace it.

 

[Motodox]

Did you test the spark at the coil & the spark plugs with the gap tester? What were the results? With it just shutting off like you describe, and you've got good fuel getting to the carburetor, it'd almost have to be ignition related.

It could definitely be the cap keeping it from starting but I can't see it just shutting off because of a faulty cap without some other symptoms. Spitting & sputtering or something.

If the spark at the plugs is good & happening at the correct time then you've got to move on to something else. If you've got good compression, good clean fuel getting to the combustion chambers & good spark at the correct time, it has to run. At the very least, it should try to run. Let us know how it goes with the new cap & stuff & how that spark tests out.

I just looked at my spark gap tool & it's about 7/16" it shows for electronic ignition as far as how far of a gap to set it at. Good luck. Jim.

Thanks Jim,

The procedure I did to check timing is I got the #1 cylinder on tdc on compression stroke. On the bell crank the notch was pointing right at 0 and I pulled the cap and it's pointing right towards #1 spark plug wire terminal.

That's the correct way to check it right?

And Jim I have tons of spark out of the coil with my spark plug gap tester, but at the end of plug wire it seems intermittent maybe and definitely a weaker spark.

 

[Motodox]

Which pertronix unit did u purchase or is on it. Pertronix 1 or 2. If it is one most likely there is an issue with the pertronix. I can clarify if why, if u have pertronix 1. I had same issue and purchased pertronix 2 and all starting and running issue were gone.

How can I tell if I have the 1 or 2? I'd imagine it's the one seems how I've had it on for 2 seasons now. It has the 3ohm flamethrower coil. And the ignitor module under cap is black. If that helps identify.

Were you still getting spark and still not starting. I even checked the ignitor with the magnet in the sleeve to see if it was reading and it is.

 

[Motodox]

the cap has carbon arc tracing in it from point to point. replace it.

By carbon tracing are you talking about that redish dust looking stuff on the bottom of cap between the terminals.

I did order new oem wires and the Sierra kit for cap and rotor.