VP 4.3 GL-B - Spark issue

Mymarcec

Cadet
Joined
Aug 13, 2024
Messages
19
I hope you can help with this issue driving me crazy.

VP 4.3L GL-B 2004. It's been sitting for almost a year. Wouldn't start, carb was bone dry so replaced fuel pump. Fuel flowing well now (almost too well) when turning engine over. Still not starting.

Checking spark from ignition coil, there is one spark when first turning the key and one spark when turning it off, but no spark while engine is turning over. I've replaced the ignition coil, pickup coil inside the distributor, and ignition module but still have the same issue from the main coil - one spark at the start, one spark at the end of ignition attempt nothing in between....

Haven't bothered checking plugs yet, figured if there is no sparking getting to them, they're not going to fire anyway.

I've been searching through the forums for ideas, but can't find anything. As I write this, I realize I should check for continuity of the wires between the ignition module and the main coil - I'll do that in the morning.

Any other ideas? Thanks for your help.
 

Fun Times

Moderator
Staff member
Joined
May 16, 2009
Messages
9,049
You may want to try checking and/or bypassing the ignition key switch to see if the engine will start/spark.

Does your boat setup have a lanyard safety kill switch? Sometimes they go bad and act funny.

How are the gauges acting?
 

Lou C

Supreme Mariner
Joined
Nov 10, 2002
Messages
12,692
I’d check the ignition switch positions to see if you are losing voltage….
B terminal, red wire, gets batt volts when batt switch is on
I terminal, purple wire, gets batt voltage when you turn the ignition to on
S terminal, yellow/red wire, gets battery voltage when you turn to start
Sounds like you could be losing power on the I terminal….
 

Mymarcec

Cadet
Joined
Aug 13, 2024
Messages
19
You may want to try checking and/or bypassing the ignition key switch to see if the engine will start/spark.

Does your boat setup have a lanyard safety kill switch? Sometimes they go bad and act funny.

How are the gauges acting?
I'll try the bypass idea. I tried bypassing the kill switch (and neutral safety switch) with no luck. I haven't been watching the guages (too busy looking back), but will have a look.
Thanks.
 

Mymarcec

Cadet
Joined
Aug 13, 2024
Messages
19
I’d check the ignition switch positions to see if you are losing voltage….
B terminal, red wire, gets batt volts when batt switch is on
I terminal, purple wire, gets batt voltage when you turn the ignition to on
S terminal, yellow/red wire, gets battery voltage when you turn to start
Sounds like you could be losing power on the I terminal….
Will do, thanks
 

Lou C

Supreme Mariner
Joined
Nov 10, 2002
Messages
12,692
If you’re losing power in the I terminal of the switch the gauges should not be working because they are powered off of that terminal
 

Mymarcec

Cadet
Joined
Aug 13, 2024
Messages
19
If you’re losing power in the I terminal of the switch the gauges should not be working because they are powered off of that terminal

I know the fuel guage was working, but will check it again when I go to the boat later.
 

Mymarcec

Cadet
Joined
Aug 13, 2024
Messages
19
I know the fuel guage was working, but will check it again when I go to the boat later.
The low oil pressure alarm definitely works, and it appears to get power from the purple wire as well from looking at the wiring diagram.

Do you know, the yellow/red wire from ignition, thru the neutral safety, thru the harness, to the starter relay then solenoid - I assume this is just to engage the solenoid and starter? When I unplug the nuetral safety switch or put the boat in gear, the starter won't engage. The solenoid also connects to the purple, and also an orange wire to the alternator - what does the orange wire do?
 

Mymarcec

Cadet
Joined
Aug 13, 2024
Messages
19
The low oil pressure alarm definitely works, and it appears to get power from the purple wire as well from looking at the wiring diagram.

Do you know, the yellow/red wire from ignition, thru the neutral safety, thru the harness, to the starter relay then solenoid - I assume this is just to engage the solenoid and starter? When I unplug the nuetral safety switch or put the boat in gear, the starter won't engage. The solenoid also connects to the purple, and also an orange wire to the alternator - what does the orange wire do?
One more question. Looking at the wiring diagram and the brown and pink wires that run from the distributor ignition module back to the main coil - the pink wire has a resistor. Do you know how much resistance this should have? Or how to test it?
 

Mymarcec

Cadet
Joined
Aug 13, 2024
Messages
19
I’d check the ignition switch positions to see if you are losing voltage….
B terminal, red wire, gets batt volts when batt switch is on
I terminal, purple wire, gets batt voltage when you turn the ignition to on
S terminal, yellow/red wire, gets battery voltage when you turn to start
Sounds like you could be losing power on the I terminal….
There is power on the purple wire at the helm (guages all work), but not on the purple wire at the coil or alternator. Must be a break somewhere. I am going to check the 10 pin connector when I get a chance next.
 

ESGWheel

Chief Petty Officer
Joined
Aug 29, 2015
Messages
469
Two things confuse me:
(1) Fuel flowing well now (almost too well) when turning engine over.
Does this mean you are smelling fuel as you are or post craning the engine as if its flooding? Its possible your float / needle-seat are not closing and flooding the engine causing it not to start.

(2) Checking spark from ignition coil, there is one spark when first turning the key and one spark when turning it off, but no spark while engine is turning over.
This is not clear to me. Do you have the coil high tension wire pulled out of the distributor with it held close to a ground and observe a spark when you first turn the key to run? And again when you turn it to off? OR observing only one spark as the engine cranks and another when it stops cranking?

In either case you should be able to power the coil directly from the battery and bypass all the other switches, etc. to see if you are getting spark when cranking. This is what folks above are referring to by “bypass.” First disconnect all the other wires to the + terminal of the coil and use a jumper to the battery positive post and crank.
 

Mymarcec

Cadet
Joined
Aug 13, 2024
Messages
19
Two things confuse me:
(1) Fuel flowing well now (almost too well) when turning engine over.
Does this mean you are smelling fuel as you are or post craning the engine as if its flooding? Its possible your float / needle-seat are not closing and flooding the engine causing it not to start.

(2) Checking spark from ignition coil, there is one spark when first turning the key and one spark when turning it off, but no spark while engine is turning over.
This is not clear to me. Do you have the coil high tension wire pulled out of the distributor with it held close to a ground and observe a spark when you first turn the key to run? And again when you turn it to off? OR observing only one spark as the engine cranks and another when it stops cranking?

In either case you should be able to power the coil directly from the battery and bypass all the other switches, etc. to see if you are getting spark when cranking. This is what folks above are referring to by “bypass.” First disconnect all the other wires to the + terminal of the coil and use a jumper to the battery positive post and crank.
Thanks for the thoughts and questions.
on (1) flooding is possible, there is a lot of fuel pumping when turning the engine over.
(2) The latter, one spark as engine starts to crank, and another when it stops cranking. No spark in between.

The bypass from battery to coil positive post is what I'm going to try next since there is no power to the purple wire in the engine bay when the key is on (there is power to purple at the helm). I was busy with other things today and hope to try this tomorrow.

Then need to check the connector for the purple wire issue as well.
 

ESGWheel

Chief Petty Officer
Joined
Aug 29, 2015
Messages
469
On a carbureted engine fuel is delivered in only one of two ways (1) thru a venturi effect (air flowing down the throat of the carb causing a low-pressure that in turn draws fuel into its airstream) and (2) the accelerator pump (a plunger like device that spits fuel into the throat of the carb when the throttle is advanced). Simply cranking the engine will not ‘force’ fuel into the engine, i.e., the action of the fuel pump does not put fuel into the carb throat (and thus the engine). The fuel pump only puts fuel into the carb float bowl until its full and then its needle and seat shut it off from overflowing and flooding the engine. This is exactly how your toilet works > it fills will water until the float shuts off the water flow. Please understand I am assuming you are not familiar with this action of the carb based on your comments.

Also given “bone dry and sitting for a year” its not uncommon that the needle / seat need to be replaced and possibly the float, i.e., a Carb Rebuild.

If you are indeed smelling fuel while cranking, be extra cautious when checking for spark. Most folks think its liquid gas that ignites but, it’s the vapors. Again, you may be aware of this so please take no offence. I truly am only trying to highlight a safety concern.
 

Mymarcec

Cadet
Joined
Aug 13, 2024
Messages
19
On a carbureted engine fuel is delivered in only one of two ways (1) thru a venturi effect (air flowing down the throat of the carb causing a low-pressure that in turn draws fuel into its airstream) and (2) the accelerator pump (a plunger like device that spits fuel into the throat of the carb when the throttle is advanced). Simply cranking the engine will not ‘force’ fuel into the engine, i.e., the action of the fuel pump does not put fuel into the carb throat (and thus the engine). The fuel pump only puts fuel into the carb float bowl until its full and then its needle and seat shut it off from overflowing and flooding the engine. This is exactly how your toilet works > it fills will water until the float shuts off the water flow. Please understand I am assuming you are not familiar with this action of the carb based on your comments.

Also given “bone dry and sitting for a year” its not uncommon that the needle / seat need to be replaced and possibly the float, i.e., a Carb Rebuild.

If you are indeed smelling fuel while cranking, be extra cautious when checking for spark. Most folks think its liquid gas that ignites but, it’s the vapors. Again, you may be aware of this so please take no offence. I truly am only trying to highlight a safety concern.
Thanks for the reminder. It doesn't take much for a big boom ;)
 

Mymarcec

Cadet
Joined
Aug 13, 2024
Messages
19
I think I've solved my spark issue, although the solution has raised a big question:

Reminder, the purple wire at the helm has power when key is on.
I checked the purple wire on both sides of the 10-pin connector and no power on either side. I followed wires all over the place and found an unattached connector down behind the motor on the left side - it had two purple together and one black wire (in a two pin connection) and appears to be a factory connector. It was badly corroded and the purple wires easily pulled out of the connector. I cut the corrosion away and trimmed the wire back a little. With the key on, one purple was hot (~13v) , the other nothing. I could not find anything this connector should be on, so I connected the two purple wires and now I have power at both sides the 10 pin connector and at my coil.

So it appears that this connection (which appears to be factory quality) is on the helm side of the 10-pin connection but in the engine bay, and I don't see any reference to it in the 4.3 GL wiring diagrams that I can find. On the motor side of the 10-pin is the coil, alternator, solenoid and engine alarm. Maybe something that the boat manufacturer added, although I can't see what...

Any ideas?
 

ESGWheel

Chief Petty Officer
Joined
Aug 29, 2015
Messages
469
Post your make, model, and year of your boat. Someone with same may have an idea.

And just curious, does it run now?
 

Mymarcec

Cadet
Joined
Aug 13, 2024
Messages
19
Post your make, model, and year of your boat. Someone with same may have an idea.

And just curious, does it run now?
2004 Four Winns 180 Freedom

I have spark now, but still putting it all back together. Water was off at the storage yard today, so couldn't start it. Hopefully tomorrow.
 

Fun Times

Moderator
Staff member
Joined
May 16, 2009
Messages
9,049
I'd say take a photo of it all to see if the connector rings any bells but unfortunately the website server isn't accepting photos at the moment as it seems the server lost its spark too. :D You'd have to use an outside photo hosting website and link it here to be able to share.

Hope you found the issue as it seems like you did...Keep us updated and good luck.(y)
 

ESGWheel

Chief Petty Officer
Joined
Aug 29, 2015
Messages
469
For the connector > I am now thinking it may have been for some auxiliary device not installed but they used the plug as a junction box (the two purple wires together). So, unless someone comes up with the ‘here is what it is for’, the priority now is to get this running.

While you do have the choice of Shop or DIY, please allow me to encourage you to DIY. Here is why:
Given the unknown nature of what all the issues are you may be looking at a fairly large repair bill as the shop goes thru the troubleshooting and maybe finding multiple issues. If you have a good relationship with a shop and trust them, this may be the most expedited way to get on the water.

However, I suspect this is a new to you boat that you got a good deal on and were looking forward to solving its issues. And frankly speaking it’s both fun and rewarding to do so.

But there is more: back to the cost at the shop comment > these engines need 3 essentials things to run: fuel, spark and compression. It’s always good to think in these basic terms because any one of them can cause it not to run. So now you have spark. I suspect you have too much fuel (wet plugs) but do you have compression? In other words, if the motor does not have compression you are going to pay the shop to tell you need a rebuild vs. doing a simple check on your own.

Thus, I suggest continuing to check out the basics and go from there. If still stuck or unsure what to do, that is what this forum is for. Folks will help.

Here are two steps you can readily do. Note I assume you do not have a compression gauge but if you do, then do the compression test per procedure.

With the coil disconnected (so no power to the + side of the coil) remove the spark arrestor so you can look down the throat of the carb. Use a flashlight. Fully open the throttle. Have someone crank the engine over for 15 or 20 seconds and do two things (1) look for liquid fuel spitting into the carb and (2) listen to how it cranks.
  • If fuel spitting, you have a needle / seat / float issue and need carb rebuild (easy to do).
  • If the engine sounds like WRR – WRR – WRR – WRR that means the compression is probably ok. If it goes Wrrrrrrrrrrrrrrrrr, then issue with compression. While not 100% fool proof it will be an indicator that if the WRR WRR WRR and you rebuild the carb you will get a running engine.
Oh, my favorite part of DIY? Getting an excuse to buy new tools 😊
Please continue to post how it goes!
 
Top