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No spark

kevin_z

Regular Contributor
1995 454xl. Boat ran great Memorial day weekend. After our little storm last weekend, I got onboard to get ready for this weekend. PT engine no problem, STBD will not start. No spark from coil to distributor. I swapped coil, module, cap, rotor, oil pressure switch, coil wire. After I swapped all that, the PT engine fired up. Still to spark on PT. I don't think the MSTS components has anything to do with the initial spark.
What am I missing??
 
Yes. Power to coil. I did continuity check on all grounds. Only thing that i have not swapped or replaced is the coil pick up and the battries. Battries are 3yr old and well maintained.
 
a bad pickup coil will cause a no spark...think the MSTS manual has the ohm values if it has failed 'hard'...
 
received the new pick up coil. Ohm it out 0.843. Ohm existing pick up coil 0.846. I don't think that's the issue. I did notice that my battery charger is at 20amps. So could I have volts, but no amps to the coil???
 
.... I did notice that my battery charger is at 20amps. So could I have volts, but no amps to the coil???

not sure what you are leaning to w/ the charger...i would hope it is not at 20 amps continuously - that would not be good if accurate...
 
FIXED!!! I pulled the distributor to replace the coil pick up. Once I knocked the pin out and removed the gear, the shaft would only come out a couple inches. It was rusted.
Went to store and bought a complete new distributor. dropped it in, fired right up.
Question: Is there a difference from a distributor from a auto parts store or one from a marine store?? Big price difference for sure,
 
Yes, there is a difference between marine rated distributors and ones available for automotive use. The marine engine typically is made with a different camshaft profile and different timing advance. This is because marine engines run with more throttle and higher loads for long periods of time. The different advance curve typically means that the mechanical advance is different and there is no vacuum advance. So the automotive distributor could bring some engine performance differences that are noticable in the short term, or could damage the engine in the long term. I don't know the specifics of your engine and your replacement distributor but it is a potential issue.

More importantly, the marine distributor is designed to prevent the sparks within the distributor from igniting fuel fumes in your engine compartment that could build up to explosive levels in case of a fuel leak. This change is made by sealing up the distributor, or by covering the vents with flame arresting screens. It is not a do-it-yourself job unless you really know what you are doing and since it is a real life-or-death safety issue, the wise course of action is to get the correct distributor. Also the only legal course of action.

As an aside, the vents (usually in the base) are there to prevent the build up of ozone from the sparks as the ozone is very corrosive so they are important unless the distributor is designed to be sealed.
 
I'd agree with CaboJohn on the sealing aspects but the advance curve issue is a moot point because it doesn't apply to an EST distributor.

So, if you have the old distributor, look for holes that go thru the body to where the spark travels. My guess is the old cap fit the new distributor so that shouldn't be an issue as long as the cap is seated all along its perimeter...if you find any holes, they should have fine screens to mitigate any unwanted ignition concerns. If there are no penetrations, there shouldn't be any issues....that's what the SAE sticker means on the marine units.
 
I did not know what kind of spark advance the OPs 454 had, so it sounds like he should be OK if the vents have screens. I got to thinking about my distributor issues on my 5.7 engines and did a little research to see how the automotive versions differ (maybe I should switch out as well). Turns out, the standard automotive Vortec distributor is vented and does have screens.......BUT.... they have so many problems with corrosion (as do I) that GM has put out a tech bulletin (http://digitalcartography.com/n0eq/astro/DistributorScreen-GM-TSB.pdf) recommending that the screens be punched out to improve ventilation. I don't think I want to do that on my marine engines! And some mechanics are even drilling larger vent holes in the distributor which would really be a no-no for marine use.

I will try and check for crud on the screens when (and if) I get back to the boat. After that, I don't know.

Oh, and I did find the the reduction in spark gap from .060 to .040 I posted on earlier, was in fact recommended by GM in an earlier tech announcement. Apparently it never made it to the marine world as Crusader is sticking to the .060 gap recommendation.
 
If it's the newer style elect. distributor, the marine and auto versions are the exact same I have compared them (and their part numbers) side by side with AC Delco auto distributors, and swapped several of them out as well.
 
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