2005 Mercury 115 EFI 4 Stroke won't start

[davidgmiller]

I went this past Saturday to wake the beast after her winter sleep, charged the battery, she started up first time no problems. Let her run for a while, turned the engine off, I wanted to double check the battery connections, went to start her back up, she started for a sec, spit and sputtered, then died and won't start back. I checked the 20amp fuse's, I replaced the fuel filter and changed the plugs still won't start, turns over but wont fire. I pulled one of the plugs after turning over a few times and they are bone dry. I also hear a clicking noise when I turn the key on, the sounds lasts for a second or two, then stops. I'm assuming that sound is the electric fuel pump, but I would not expect the fuel pump to sound like that. Also I checked the fuel just to make sure no water was in there, and it's all gas. Someone said that the vapor canister should be drained to see what's in there, but I can't find it. (really don't know what I?m looking for) Also I think the fuel pump is located in that canister.

A couple questions, 1) should the electric pump being humming or clicking (I think humming) and 2) if the pump is out, how hard is it to change? the problem is my boat is in a wet slip a good ways from the boat ramp. Will be hard to get it to the trailer. Not out of the question, but will be hard.

 

[coastalrichard]

Re: 2005 Mercury 115 EFI 4 Stroke won't start

What's the condition of your primer bulb? Will it get firm? Does it collapse? Are you getting a good spark?

 

[davidgmiller]

Re: 2005 Mercury 115 EFI 4 Stroke won't start

my primer bulb is good, replaced last year. I even disconnected it and pumped some gas in a glass so I could see if it had water in it and It will pump and stay firm. I didn't however check for spark since I was by myself. If it was getting fuel I would have thought the plugs would have been wet.

 

[CharlieB]

Re: 2005 Mercury 115 EFI 4 Stroke won't start

You really need a service manual to at least identify components.

Check here
http://1manual.com/Mercury manuals/Service_Manual_Index.html
and
http://forums.iboats.com/showthread.php?t=309079&p=2072211#post2072211


The high pressure fuel pump should run for a few seconds when the key is first turned on to build fuel pressure in the fuel lines to the injectors. On that line there is a pressure port that looks quite similar to a tire valve. With a high pressure fuel gauge test the pressure here. If pressure does not reach factory setting you may have a problem with the high pressure pump OR the fuel pump driver in the EFI computer.

You can test the fuel pump easily, locate the two wires to the fuel pump, one is constant 12 V, the other is ground controlled by the computer. Remove the ground wire and rig a jumper from a good ground to the ground terminal of the pump.

Does the pump run now and build fuel pressure?

If so it is quite likely the fuel pump driver is bad. Remove the computer and send it in for driver replacement.

 

[davidgmiller]

Re: 2005 Mercury 115 EFI 4 Stroke won't start

Thanks for the link to the service manual. When I turn the key on, I hear a clicking sound for a second or so then it shuts off, just like I would expect the fuel pump to do however it's clicking and not humming. Secondly I tested the injection port and there was no presure at that valve. I will see if I can test the fuel pump.

thanks

 

[Don S]

Re: 2005 Mercury 115 EFI 4 Stroke won't start

If the electric pump isn't pumping, then it's not going to start. Can we assume the pump used to hum for 2 seconds and not just click?

 

[davidgmiller]

Re: 2005 Mercury 115 EFI 4 Stroke won't start

Good question, with the cowling on, I don't think I would hear the pump come on, with that said, probably wouldn't hear the clicking either. I'm going to do some testing this weekend. Thanks

 

[mtpmarine]

Re: 2005 Mercury 115 EFI 4 Stroke won't start

Good question, with the cowling on, I don't think I would hear the pump come on, with that said, probably wouldn't hear the clicking either. I'm going to do some testing this weekend. Thanks

Were you ever able to figure out what was wrong with the engine? I have the exact same issues with my 2005 115 Merc and am at a loss. Thanks in advance.

 

[PontoonboatFun]

Re: 2005 Mercury 115 EFI 4 Stroke won't start

studying fuel injection problems on mercury EFI 4 stroke and found your posting. with a fuel module there is a vent to the intake manifold. can remove it and check fuel level ~2/3 up. check your model and parts for these to see how there are set up. mine had a ruptured hose in the fuel module (115hp 4stroke EFI 2007) get your serial number and look up the parts to compare.