one.cool.devil Posted October 5, 2017 Report Share Posted October 5, 2017 I have never had a problem with my 2006 B52. The boat has a 5.7 350 PCM motor in it. The situation...I throttled up and got to full speed and after about a minute it shut down. I cranked the motor but it wasn't starting. We anchored and just floated there for a while. After about few hours I tried to start it again and got it running. I gave it a little gas and it died again. It hasn't started since. Its acting like its not getting fuel but I am trying to systematically troubleshoot the issue, Spark, fuel, air, etc.... With all the electronics and sensors on the motor I am not sure I can diagnose if I am getting a spark. Its like going down a rabbit hole so to speak. I haven't got a chance to check the fuel pump. Before I dig any deeper, has anyone had an issue like this before or have any ideas? Thanks in advance for the advise Quote Link to comment Share on other sites More sharing options...
Hondatech117 Posted October 5, 2017 Report Share Posted October 5, 2017 Narrowing it down to what component of combustion is missing will be easy. If it currently doesn't start and don't have a spark tester a good ol' screwdriver will work in a pinch. Put the screwdriver in the end of the spark plug wire in lieu of the spark plug and hold it close to a ground, have someone crank it over and see if you have spark jump the gap. As far as the fuel goes, either crack the line or hook up gauge to the service port, if you have one. If you crack the line, have someone either cycle the key or crank it over, should have some mini Bellagio coming out of there. You should be able to tell if its lacking spark or fuel in under 30min. Then troubleshoot based on what you find. Quote Link to comment Share on other sites More sharing options...
one.cool.devil Posted October 5, 2017 Author Report Share Posted October 5, 2017 Thanks for your response. I tried the screwdriver trick and I didn't get a spark. Then checked to see if voltage is going to the distributor during cranking and got nothing. I then checked the crank sensor for voltage during cranking and got nothing. I stopped after that because I was running into dead ends and running out of daylight. my next day off I am going to try and check the fuel pressure. Quote Link to comment Share on other sites More sharing options...
bloodiestcadaver Posted October 5, 2017 Report Share Posted October 5, 2017 What kind of ignition coil system? individual for each cylinder? or one coil to supply secondary to the cap? Quote Link to comment Share on other sites More sharing options...
Bosshog Posted October 5, 2017 Report Share Posted October 5, 2017 Fuel pump one.cool.devil 1 Quote Link to comment Share on other sites More sharing options...
one.cool.devil Posted October 11, 2017 Author Report Share Posted October 11, 2017 The engine has one coil. I had purchased a new one and installed it, no change. I cant hear the fuel pump turn on because of the depth gauge beeping. I do have pressure in the fuel lines but I don't have a gauge to check how much pressure its putting out. Quote Link to comment Share on other sites More sharing options...
Racer808 Posted October 11, 2017 Report Share Posted October 11, 2017 The engine has one coil. I had purchased a new one and installed it, no change. I cant hear the fuel pump turn on because of the depth gauge beeping. I do have pressure in the fuel lines but I don't have a gauge to check how much pressure its putting out. Any autoparts store will let you loan one. Quote Link to comment Share on other sites More sharing options...
UNSTUCK Posted October 12, 2017 Report Share Posted October 12, 2017 Why are you going after fuel when you already know you dont have spark? Quote Link to comment Share on other sites More sharing options...
bloodiestcadaver Posted October 12, 2017 Report Share Posted October 12, 2017 you can test the trigger to the coil really easy with a test light. assuming your one coil has 2 wires,(not counting the secondary wire that goes to the cap) one should have battery voltage when key on and the other should have a pulsing ground from the ignition module or distributor. with the test light connected to a good ground(verify by touching the positive battery cable) probe one wire to make sure it has battery voltage. If it does then your other wire will be for the trigger. now attach your test light to the positive terminal on the battery( verify connection by now touching a good ground) probe the other wire while cranking the engine. If the test light flickers then the coil should be firing. Now since you have replaced the coil and assuming it is not defected out of the box, and the light is flickering, then you need to check your secondary wire to the cap, as well as the cap and rotor, maybe it got wet? If it is not flicking then your need to check your pick up coil or ignition module, which I would need to see a pic or know what kind of distributor it is. I was an auto mechanic but I am new to the boat world. but should be the same concept. Quote Link to comment Share on other sites More sharing options...
one.cool.devil Posted October 31, 2017 Author Report Share Posted October 31, 2017 Okay, I got fed up and took it into the shop. The problem was a bad fuel pump relay. The mechanic said the fuel pump relay is on the same circuit as the ignition coil. That is why I wasn't getting any spark. Don't know why MB would install them on the same circuit, it makes troubleshooting a bit difficult. Thanks for all the replies. Quote Link to comment Share on other sites More sharing options...
Shawndoggy Posted October 31, 2017 Report Share Posted October 31, 2017 It's not MB, it's PCM. Good you got it going. I'm late to this thread, but another quick test for relays would've been to just switch your starter and fuel relays (both are basic bosch 5 pin relays). you'd know in about 90 seconds whether you had a bad relay, because you'd go from a crank but no fire condition to a no crank condition. I keep a $2 relay on the boat just in case. oldsmobiledriver and bloodiestcadaver 2 Quote Link to comment Share on other sites More sharing options...
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