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Misfiring cylinders update, next steps.

surfnfisher

Contributing Member
Okay, started new thread for next steps.
2 cylinders not firing. Both have spark. Swapped coils no change but coils work on other cylinders.
Tested compression. All cylinders have compression.

How do I test individual cylinders for fuel?
and also test fuel pressure?

any other suggestion/help appreciated.

Thanks
Surfnfisher
 
Before you go any further may I suggest you get a dealer to check the motor with DrH, it could be something very simple.When you say compressions good,what were the readings?
 
A quick way to check if you have 115HP A or 130 hp A , not 115hp D 135 hp A 150 hp A, they have a CMP and CKPs instead of a pulsar coil . No: 1 & 4 pistons fire together and No 2 & 3 pistons .you have changed the coils around and confirmed that it is working good now just change the pulsar coil wires around all you are then doing is changing the firing order around so instead of no 1&4 firing 1st it will be no 2&3 that will fire 1st this will confirm if it is the pulsar coil or not .then you go to the next step if it still not firing .when you do this test just take all the plugs out .When you finished put the wires back where you found them.
 
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Surfnfisher - OK - it looks like plugs are good and coils are good. So as you have deduced, next look at the injectors on those two non-firing cylinders. There is no specific fault code listed for a mis-behaving fuel injector, however, I would suspect it should throw a code "1". But as Ian has suggested, Dr. H would likely identify if any of the injectors are bad or clogged, or there is a problem with the injector wiring.

I've got no experience testing injectors on the 225, but it seems the first step would be to check the electrical connectors on top of the injector body - make sure that they are clean and making good contact. While doing that, you can test the resistance between the two electrical prongs on the injector body. They should all have about the exact same resistance. But I don't know the resistance spec for this engine. Recognize that this test just determines whether the magnet coil inside is OK. It doesn't test for a clog, broken spring or other problem inside the injector.

Beyond that, I would remove the injectors and have them professionally tested and cleaned. Replacements are about $77 USD on boats.net.
 
Okay, I’ll try to test the injector connectors.’
The compression was 175 in the misfiring cylinders and 185 in the others . This was taken on a cold engine about 55deg outside. Motor hasnt been started for a couple weeks.
 
If you are able to run the motor connected to a Oscilloscope and then check the CMP and CKP these 2 control spark and injectors. by observing the wave patterns you should get a clearer picture of whats going on then you can draw your conclusions from there instead of jumping around all over the place.
 
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Do yourself a favor, pull the injectors and have them cleaned professionally. If you have compression and ignition, the only thing left to check is the injectors. Chances are they are just clogged, worse case is the circuit is open and they need to be replaced.

If you want to check the wiring circuit on the engine, get this cheap Noid Light Kit.

https://www.harborfreight.com/11-piece-noid-light-and-iac-tester-set-97959.html
 
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