no spark at coil

[Michel daou]

Hi I am new to this site, i have a 2003 mercruiser 6 cyl 4.3lx engine serial no 0M688581, i have no spark at coil. i have done the compleet Mercruiser 2003TB5Troubleshootingchart test, have changed the coil and electronic module and also the sensor inside the dist. but still no spark at the coil.

Mercruiser 2003TB5Troubleshootingchart

Can anbody help me this

 

[rte592]

Re: no spark at coil

Not sure if it helps
Boats are notorious for bad grounds or conections
usually from fuses and or wire corrosion

 

[Michel daou]

Re: no spark at coil

i have changed the wires also

 

[rte592]

Re: no spark at coil

I'd start checking wires back from the coil for voltage
With the new parts installed it should have spark
any way to test the new and or old parts?
Ignition switch problem?? Can you hot wire it

I'm just throwing out Ideas here 2003 boats are way newer that I've messed with.

 

[Don S]

Re: no spark at coil

Assuming you have done all the voltage tests correctly in this troubleshooting chart, and all is well. Then you may have nothing more than a bad rotor, distributor cap, or coil wire from cap to coil.

 

[rte592]

Re: no spark at coil

Note to self Don is the go to guy for information.

I'm still new to boats and old school.
I just picked up a 1990 ultra mercruiser so knocking on teak I'll have years of trouble free boating

 

[Michel daou]

Re: no spark at coil

Will any coil do the job or does it has to be a specific coil for that engine? If I don't have spark at the coil, it can't be the rotor or dist cap, right?

 

[Don S]

Re: no spark at coil

Shouldn't be, but I don't know how or where you are testing for spark. Have you checked the coil wire?

Get the right coil, then you don't have to wonder if it will work or not.

 

[Pete104]

Re: no spark at coil

Did you have a running engine prior to the new parts?
Did you check the lanyard?
Did the shift interupter get hung up somehow?

 

[Don S]

Re: no spark at coil

i have a 2003 mercruiser 6 cyl 4.3lx engine serial no 688581,

What is the letter in front of your 688581 number, without that letter the number is meaningless.

 

[Michel daou]

Re: no spark at coil

The letter is OM. I have checked the coil wire, it's ok, does not have a lanyard. I also had the switch interupter checked. Any other suggestions?

 

[Don S]

Re: no spark at coil

Did you actually do the tests shown in the troubleshooting chart or just throw some new parts at it and hope for the best?

As an example, did you unhook the gray wire from the tach per step 1? you can't do that from the coil as it's tied into the wiring harness.
Did you have full battery voltage in step 3 ?

 

[Pete104]

Re: no spark at coil

I didn't think ANY boat was manufactured without a lanyard anymore. Or is that a NMMA thing & not Coast Guard.
What kind of boat?
Did you have spark before the new parts?

 

[Michel daou]

Re: no spark at coil

There is 12v at the coil, but Don your right, I did the test with the gray wire at the coil and not at the Tach. I will do that tomorrow. The boat has no lanyard, its using a automotive swith and have worked always with it. And, Yes I had spark, the engine was running perfect. I did every test in the chart exept for the gray wire at tach. Thanks so far, will get back to you guy's tomorrow.

 

[Don S]

Re: no spark at coil

And, Yes I had spark, the engine was running perfect

If this was in reply to Pete's question "Did you have spark before the new parts?" then why all the new parts. Then, since it had spark before all the new parts, then you either put a defective part in, or you hooked something up wrong.

PS, where are you located?

 

[Michel daou]

Re: no spark at coil

I am the third person to help a friend of mine with this boat, all the parts have been changed before me, I have changed only the new automotive coil for another new one, which I am not sure now if I need another type of coil, but even an automotive coil shoot give me spark when it gets 12v at + coil!!!
My friend is not sure if there was 12v at the beginning at the coil.Just trying to help him out.
we are in Curacao. (Caribbean)

 

[Bondo]

Re: no spark at coil

My friend is not sure if there was 12v at the beginning at the coil.

Ayuh,... Which is step #3 in the diagnostic tree...

If ya ain't got 12v at the coil (+), ya gotta find out why, before movin' on...

 

[Michel daou]

Re: no spark at coil

Ayuh,... Which is step #3 in the diagnostic tree...

If ya ain't got 12v at the coil (+), ya gotta find out why, before movin' on...

I have 12v at the coil (+)

 

[Michel daou]

Re: no spark at coil

Always had 12v at coil (+) but never a spark from the coil.

 

[Pete104]

Re: no spark at coil

With the key on, crank it from the solenoid. 12volts to yellow wire w/red tracer.

You are doing this with good ventilation, correct?