Mercruiser 350 EFI---wont start

[Maclin]

Re: Mercruiser 350 EFI---wont start

I don't know what that is. Water is not red tinted like that even when it is mixed in and then separates. That looks like some kind of separation of the fuel itself. Plus that other hard stuff floating around in there, what a mess.

Was the filter new this year? and do you treat your fuel for a winter layup? I bet you do because you said it was ok before that. If you do take care of the fuel over the winter then this is probably from that batch you got at the Marina during that Fateful Friday Fillup.

I feel for you, that stuff has to come out and your fuel injection system purged somehow. After all that you will need new plugs too I bet.

 

[Rinkerguy24]

Re: Mercruiser 350 EFI---wont start

well the color did throw me off a bit too, but i figured that was just because it was mixed with the gas...yes that was this years filter on there....and yes i treat the gas every year

 

[hard-3]

Re: Mercruiser 350 EFI---wont start

that brown looking stuff looks like varnish. what ever was in that load of fuel must have disolved the varnish from the inside of the fuel tank. I would try some seafoam and see if it helps. maybe siphon off the bottom of your fuel tank to get out the sludge when it settles out. let it settle good then siphon out with a hand pump.

 

[Rinkerguy24]

Re: Mercruiser 350 EFI---wont start

well this am i siphed out all the water that would possibly come out. was putting it into a gallon size jar so i could see it....when i was getting just a drip here or there is when i stopped....so hopefully i have gotten it all out , i would say there was abt 1 cup + of just water that i got from the tank...

got new plugs and new separator today that i will put on and try this pm..

 

[gdoerr]

Re: Mercruiser 350 EFI---wont start

I have a 5.0L Merc in my Chaparral 240 - had the same thing happen. Can you hear your fuel pump prime when your turn the ignition to the on position? If not - it may be faulty ECM - that was my issue - expensive.

 

[Rinkerguy24]

Re: Mercruiser 350 EFI---wont start

yes the pump is running.......

 

[Don S]

Re: Mercruiser 350 EFI---wont start

I'm with Dave. An engine cranking to slow WILL NOT start an EFI engine.
Hook your test voltmeter up to the battery and try to start the engine. What does the meter read while you are cranking?

You never did answer the above question, but you did say this.

finally got a chance to try some things.....battery shows 12 v on meter, under load holds at 10 volts..normal correct??

You really need to put a test meter on the battery. See what the actual voltage is and then have someone crank the engine over and you watch and record what voltage the test meter shows.

I'm fairly sure that with less than 10.5 volts, you will not get a signal from the ECM to turn on the fuel injectors.

 

[Rinkerguy24]

Re: Mercruiser 350 EFI---wont start

last time it did it i put the charger on it on start and it still did nothing.....

sunday i went out started it up let it run ..turned it off and on let it sit, start and let run did this for abt a 2 hour period, trying to get it to not start but it would not do it....so i let it sit for 35 minutes went and tried it and it fired right up so i let it idle then shut it off.....hooked it up and took it to the lake to go run out the old gas that was left.....backed down the ramp and it would not start...pulled it up and opened the hatch removed the top cover and found that it was as dry as a bone no gas was getting in there(at the carb)...its the darndest thing i have ever experienced in my life so i took it over and dropped it off at the boat shop and asked them to fix it.......problem is it probably wont do it for them.....well see..will keep yall updated.......

 

[Rinkerguy24]

Re: Mercruiser 350 EFI---wont start

went by the boat shop havent looked at it yet..while i was there they cranked it up let it run, turned it off and on several times , then it would not start due to dead battery...they put a new one in it and started it right up, off and on some more....finally they sent me out to go drive it around and burn out the gas in it....during this time i would pull in to the marina turn it off and let it set..did this 4 times in between runs letting it set for 15- 40 min. each time....never had a problem with it starting....

did notice when i was running it that it did have 3 hiccups while underway, but it was not enough to change speed or anything.....so at this point it looks like it was the battery and the water issue.....guess i will find out sunday when we go to the lake.....i thought my battery was 2 yrs old it is almost 4 yrs old.....................

 

[Rinkerguy24]

Re: Mercruiser 350 EFI---wont start

took the boat out on sunday it ran great all day did not have any problems with start up or anything........it did give a few hiccups while under way, but that was it...so i guess it is either a little bad gas left in there or some moisture........