No spark coming from ignition coil 5.0FL PMDA engine

[Michigan Jason]

I have 12 volts on the purple wire coming from the harness when the key is on, then when cranking I get 9-10 volts to the positive terminal of the coil. A large amount of voltage coming out of the coil where the spark plug wire connects to the distributor cap, but no spark. Cannot get spark anywhere. Over the weekend we took the boat out and I left the key in the run position in order to have the radio going. This gave constant voltage to the coil and 2 hours later it was literally sizzling. It hasn't produced spark since. I put a new coil in and still no spark. I have been told to chase the negative (white) wire from the coil to the ignition module, and this is where I am stuck. I cannot find an ignition module or anything of the sort, it just seems like the wire runs to a harness and that's it. Any help is appreciated.

 

[Don S]

Re: No spark coming from ignition coil 5.0FL PMDA engine

A large amount of voltage coming out of the coil where the spark plug wire connects to the distributor cap, but no spark.

How are you checking for spark, and how do you know you have a LOT of voltage coming our of the coil?

 

[Michigan Jason]

Re: No spark coming from ignition coil 5.0FL PMDA engine

Took a voltmeter and a test probe and touched it to the end of the wire coming out of the ignition coil after unplugging it to the distributor cap. Took said wire and grounded it to the engine block to see a spark. Nothing.

 

[Maclin]

Re: No spark coming from ignition coil 5.0FL PMDA engine

It won't spark unless the engine is turning.

 

[Michigan Jason]

Re: No spark coming from ignition coil 5.0FL PMDA engine

I know that, have a brand new battery with good voltage, had a friend crank the engine while I grounded the wire to the block, and nothing at all. Engine turns and all, but no spark from the coil. I have been told it is my ignition module, but have no clue where it is, or what it looks like.

 

[jerome radtke]

Re: No spark coming from ignition coil 5.0FL PMDA engine

Are you "grounding" the wire, or are you leaving a gap of approximately 1/8th inch for the spark to jump across. It needs an air gap for ignition.

Conversely you could always test it the way my Father would. He would grab a spark plug wire, and tell me to, "Turn it over." If he let go quickly, I would turn off the ignition.

 

[Michigan Jason]

Re: No spark coming from ignition coil 5.0FL PMDA engine

Are you "grounding" the wire, or are you leaving a gap of approximately 1/8th inch for the spark to jump across. It needs an air gap for ignition.

Conversely you could always test it the way my Father would. He would grab a spark plug wire, and tell me to, "Turn it over." If he let go quickly, I would turn off the ignition.

Leaving an air gap. No spark at all

 

[skydiveD30571]

Re: No spark coming from ignition coil 5.0FL PMDA engine

Did you try looking in the service manual? Here is the list of them. MD is under the "1993-2000 Charcoal color" title towards the bottom of the page:

http://forums.iboats.com/showthread.php?p=2360521#post2360521

I'd be willing to bet the ignition section of your service manual goes into pretty good detail about the module. That should help you locate it or atleast see what it looks like. And how to test it.

 

[Michigan Jason]

Re: No spark coming from ignition coil 5.0FL PMDA engine

I have the manual. No where in the ignition system diagram is there an ignition control module or ignition module.

 

[skydiveD30571]

Re: No spark coming from ignition coil 5.0FL PMDA engine

You're right. I looked at your manual and theres nothing for it. You said you have power on the purple wire, so if there's a problem upstream it has to be the negative side. It looks like it comes from the tachometer, and passes thru an optional tach amplifier with connectors on both sides. Have you followed that harness to see if you have one of those amplifer deals? If not then I'd imagine its the tach or wire from the tach.

 

[Michigan Jason]

Re: No spark coming from ignition coil 5.0FL PMDA engine

You're right. I looked at your manual and theres nothing for it. You said you have power on the purple wire, so if there's a problem upstream it has to be the negative side. It looks like it comes from the tachometer, and passes thru an optional tach amplifier with connectors on both sides. Have you followed that harness to see if you have one of those amplifer deals? If not then I'd imagine its the tach or wire from the tach.

I cannot seem to locate the tachometer amplifier. But my tach does go up when I am turning the motor over.

 

[brian wig]

Re: No spark coming from ignition coil 5.0FL PMDA engine

its under distributor cap and under rotor button and has two screws holding it two small wirescoming out of distributor i just replaced mine
http://marineengineparts.com/shopsite_sc/store/html/page442.html

 

[Michigan Jason]

Re: No spark coming from ignition coil 5.0FL PMDA engine

its under distributor cap and under rotor button and has two screws holding it two small wirescoming out of distributor i just replaced mine
http://marineengineparts.com/shopsite_sc/store/html/page442.html

That is for distributors built prior to 86? I have a 94 engine so I am guessing that mine is 94ish?

 

[skydiveD30571]

Re: No spark coming from ignition coil 5.0FL PMDA engine

According to this thread, I doubt you have the amplifier in there. I bet it's a straight shot for the gray wire from the coil to the tachometer.

http://forums.iboats.com/showthread.php?t=286492

If you find that there is no amplifer, I would run a jumper wire from the tach to the coil and see what happens. That would eliminate the wiring from the equation.

 

[brian wig]

Re: No spark coming from ignition coil 5.0FL PMDA engine

if it is after 87 youhave to take the square grommet off the wires and put it on the new module and take the round one off of new module

 

[Michigan Jason]

Re: No spark coming from ignition coil 5.0FL PMDA engine

if it is after 87 youhave to take the square grommet off the wires and put it on the new module and take the round one off of new module

I read that, I guess it is because water can get in there if you use the round grommet? Do I still need to sylicone around it to prevent water from entering? or vapors?

 

[Don S]

Re: No spark coming from ignition coil 5.0FL PMDA engine

According to this thread, I doubt you have the amplifier in there. I bet it's a straight shot for the gray wire from the coil to the tachometer.

http://forums.iboats.com/showthread.php?t=286492
.

That thread is for a Chevy engine, has a completely different igition system.

If you downloaded the electrical and ignition manual from the sticky, look section 6. It details the system and has troubleshooting info.

 

[Michigan Jason]

Re: No spark coming from ignition coil 5.0FL PMDA engine

Don, thanks for the info. I have, but my system does not seem to have said tachometer amplifier. I cannot locate it. If you can help me locate it, I would be happy. I have a new ignition module and the proper coil coming and it will be delivered within the next 15minutes. If I install these parts and still no spark, I will be looking for said amplifier.

 

[Don S]

Re: No spark coming from ignition coil 5.0FL PMDA engine

You may not have a tach amplifier. It was an option if needed.

 

[Michigan Jason]

Re: No spark coming from ignition coil 5.0FL PMDA engine

I dont think I do. I am just thinking after I put these parts on, what else it could be after all the testing that I have performed, it all leads to the module. I have the parts, they just got here, I will install and update.