havehadenough

tried everything

25 posts in this topic

Hey anyone that can help will be greatly appreciated. Have a 2003 6.2 Mercruiser EFI. Was coming in to my dock and just stalled out. No spark and power to the fuel pump or injectors. The motor will crank fine, but will not start and no prime to the pump when the key is first turned on or alarm sound check.  But after 20 seconds if the key is left on the alarm will sound with long beeps and a shorts pause continuously. Every time the alarm beeps for some weird reason I get spark and power back to the pump and injectors. It still will not start! I've changed the oil pressure safety switch, temperature switch, coil with module attached, crank sensor, main relay, fuel pump relay, check all the wiring and jump out the ignition switch. Any other suggestions would help. Thanks! 

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As I mentioned in the post, the motor cranks fine with plenty of power and the alternator is good. What puzzles me the most is no initial alarm or power to the pump and no spark but 20sec later with key on alarm comes on and power and spark come back. Plenty of cranking juice but no start.  

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Sorry to be blunt.. but stop throwing parts at it. Try to have it diagnosed. Could save you some money.

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You need to find out what this means, you said "the alarm will sound with long beeps and a shorts pause continuously." The number of beeps is most likely a trouble code.  

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15 hours ago, havehadenough said:

As I mentioned in the post, the motor cranks fine with plenty of power and the alternator is good. What puzzles me the most is no initial alarm or power to the pump and no spark but 20sec later with key on alarm comes on and power and spark come back. Plenty of cranking juice but no start.  

This is exactly why I thought maybe a safety lanyard (or the integrated switch), or the neutral shift switch (may not be the right name).  I believe that if either the latter switch believes the shifter is not in neutral or if the lanyard is missing, you will not get the "power up beep" or fuel priming, but the engine will crank and crank.  Those two items have stumped MANY a boater.  So always good to rule them out before throwing money at anything else.

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There has been once or twice I forgot to turn the lanyard on (it's an on off switch on below the shifter) and the motor won't crank if it's off. But I did jump it anyway. Also, the same thing happens if the shifter is not completely in neutral, will not crank and also jump the switch just to make sure. Do you think it could be the ECM? When I pull the plugs off I get power going in but cant find anything coming out.

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14 hours ago, Waterfun said:

Sorry to be blunt.. but stop throwing parts at it. Try to have it diagnosed. Could save you some money.

Yup this. 

 

My two cents would be to pull the batteries and have them load tested,  testing voltage alone doesn't always mean a whole lot.  Next what about the starter solenoid,  should be the solenoid next to the red fuse or reset button that's on the engine.  lastly I would be tracing all wiring to check for tightness and corrosion.

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Scan it for codes !

 

If the starter solenoid was bad the engine would not turn over.

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I did check the starter solenoid in the beginning and power going in and out. I do have three batteries a year old and the boat is inside my shop. The boat is plugged in and the batteries are fully charged. As i mentioned, the motor cranks with plenty of power. I spent hours looking over all the wiring and unless I'm missing something, it all look good. I think probably the next step is to scan for codes.

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43 minutes ago, soldier4402 said:

Yup this. 

 

My two cents would be to pull the batteries and have them load tested,  testing voltage alone doesn't always mean a whole lot.  Next what about the starter solenoid,  should be the solenoid next to the red fuse or reset button that's on the engine.  lastly I would be tracing all wiring to check for tightness and corrosion.

If the batteries were weak, it would turn over slowly or not at all. He is say that it turns/cranks over fine. I thank you said that you are getting a spark out of the plugs, yes? 

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5 hours ago, havehadenough said:

There has been once or twice I forgot to turn the lanyard on (it's an on off switch on below the shifter) and the motor won't crank if it's off. But I did jump it anyway. Also, the same thing happens if the shifter is not completely in neutral, will not crank and also jump the switch just to make sure. Do you think it could be the ECM? When I pull the plugs off I get power going in but cant find anything coming out.

Fair enough.  I thought it would crank, but it's been YEARS since I've been in that situation.  :)
 

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There might be a BIG multi pin connector at the back side of the engine. Has lots of wires in it.  The pins can loose solid contact over the years. Can cause any or several problems if 1 or more pins loose ENOUGH tension.  Separate the plug. PUSH & PULL the parts together a few times. That may SCRATCH the surfaces just enough to change your start problems & alarms. If yes.  I would recommend a great  mechanic carefully & VERY SLIGHTLY spread the split pins to make a good enough contact. Can be a boat or car mechanic.

DISCONNECT  the main batteries.  I think the pins are on the motor side of the plug.   Thin pocket knife blade will do.  You want to spread them ONLY A TINY BIT. .020 " to .030 " maximum. If there is true colored corrosion on pins ?  Definitely disconnect all battery  plus OR al the minus leads before going after the corrosion.

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There's a harness in the back of the motor but no pins. I tried to move it around but still no luck. I'm going to get some one with a scanner and try to scan for codes. 

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May seem too obvious, but did you check all the fuses / ckt breakers?  Might have popped the one for the ECM, or something similar.

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I've done that about 4x's. I didn't see one for the ECM directly. On the motor there is two relays which I've replaced, three 20amp fuses all together. In the beginning one of the 20amp fuse was blown which I believe was the fuel pump. At first I thought that was the problem, but as it turns out.

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Short of somebody doing the ECM scan, and getting lucky running diagnostic routines after all that parts had been thrown at the engine, you need to replace the entire engine now. Might be cheaper in the long run as well. JK ... ;)

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Have you checked the fuse for the fuel pump again?  Perhaps it blew a second time.  Fuses typically blow for a reason, i.e. a short to ground, or a component drawing too much current.  I'm guessing you've thoroughly checked the harnesses and connectors?  Have you tried manually applying 12v to the fuel pump?  I think the blown fuel pump fuse is the best clue you have.  Dig deeper into it.  Oh yeah, and scan for codesB).  

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I did check over and over again just to make sure it didn't blow. And your right, I was think the same thing, it had to start with the pump. I actually replace the pump because after putting 12v directly to the pump I was getting no fuel pressure. I replace the pump and solved that problem. I also did replace the relay figuring if the pump stopped and the fuse blew I thought the relay failed as well. It may still have to do something with that system. 

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