'07 Merc 5.0mpi, won't start at all

[dvan1901]

Ok, per my other post:http://forums.iboats.com/showthread.php?t=320856
I've replaced the fuel water separator, it was gunked up pretty good, and the fuel filter. I even put 5 gallons of fresh gas in the original tank. The engine will not start at all. When turning the key, I can hear the fuel pump engaging (runs about 3 seconds) and then will crank fine, but just will not turn over anymore. I have not yet put a fuel pressure gauge on it yet, but will be doing that today. What else can I check; assuming good pressure? Any fuses or sensors to check out? I would like to check a few more things because the earliest any mechanic can look at it here is the 23rd; busy season right now. Any sensors that can be reset or anything like that? Thanks!

 

[dvan1901]

Re: '07 Merc 5.0mpi, won't start at all

Ok, bit of an update. I got a fuel pressure gauge and tested it per the manual's instructions and got a zero reading. I also looked at the filter and it was dry as a bone. So, even though I hear the fuel pump spin up, it must not be functioning properly; fair assumption?

 

[dvan1901]

Re: '07 Merc 5.0mpi, won't start at all

Anyone?

 

[Bondo]

Re: '07 Merc 5.0mpi, won't start at all

Ayuh,... There IS gas in the tank,..?? Right,..??

Can the gas in the tank get To the fuel pump,..??

 

[Fun Times]

Re: '07 Merc 5.0mpi, won't start at all

Ok, bit of an update. I got a fuel pressure gauge and tested it per the manual's instructions and got a zero reading. I also looked at the filter and it was dry as a bone. So, even though I hear the fuel pump spin up, it must not be functioning properly; fair assumption?

Sorry but I have helped you the best I can I think, If you found 0 fuel psi then it is dead till you get a new fuel pump. And you really should be trying to get all of the old gas out of the boat ASAP so you will not damage the new pump when it gets installed by either you or the dealer. And like I said if you can hide every drop of old gas from both tanks and also what is inside the fuel pump tank with new filters and leave new gas sitting in it you have small chance of getting it covered. But you got to get the old gas out of their no matter what. And then you need to try varry hard to pervent this from happing again. If you put stabilizer in last year then some one did not put enough in both tanks and did not shake the boat to mix up the fuel, And did not run the engine out long enough to let it reach the engine. And their is no sensor to check if you have 0 fuel psi at the fuel rail. Good luck with this.

 

[JustJason]

Re: '07 Merc 5.0mpi, won't start at all

With an MPI adding stabil to the fuel isn't enough. you need to make a cocktail of stabil, fuel, and 2 stroke oil to winterize the fuel pumps and entire fuel injection system.

Err.. just read your other thread. If it ran fine for a month but now it does not run, and it's under warranty. Don't screw around with it, bring it in.

If your dead set against bringing it to the dealer. take out both fuel pumps, in a bucket mix up a batch of fuel and stabilizer and let the pumps sit in that for 24 hours. Reinstall the pumps and test your boats fuel system as described here.

http://forums.iboats.com/showthread.php?t=283269


On a side note... try not to start 2 threads on the same subject. Hopefully Don will join the 2 together.

 

[dvan1901]

Re: '07 Merc 5.0mpi, won't start at all

Bond-O, I'm not 100% sure yet that gas is getting from the tank to the filter and pump. I'm going to verify today by pulling the hose off of the tank selector and pouring fuel in. If I am from there, then I know its from the selector back. I'm also going to pull the lines that go from the tank to the selector, open the gas cap and put a little pressure in to see that I am getting air coming out the gas cap. If that works, then it's the switch.

JustJason; I'm not dead set against taking it to a mechanic, I actually have an appointment on the 23rd, I just want to make sure it's not something simple/stupid that I'm overlooking. Essentially trying everything you can before hooking it to a diagnostics system.

 

[dvan1901]

FIXED - Re: '07 Merc 5.0mpi, won't start at all

FIXED - Re: '07 Merc 5.0mpi, won't start at all

Went back to the boat today and got it fixed. Turns out, I needed to "prime" the fuel filter container. I disconnected the fuel line from the tank to the filter and pump and gently blew into it. I had taken the fuel filter out so I could hear air coming out the other side easily, no obstruction. I put that back on (more on this in a second) and then poured a little gas in the filter canister, turned the key to "on" and could hear the gas being sucked in. Tried to crank it, would crank, but not turn over. I thought "what the crap!" I turned the key back to on and could hear, what I thought, was the gas being pumped to the injectors...turned out there was an air leak at the connector I had previously taken off. I went back, adjusted it, and tightened it back down. Engaged the pump again, fired right up! I let it run for several minutes to ensure proper oil pressure and temp. All was good.

Thanks to you all for giving me things to try. I learned a lot about my fuel system during this process.