350 mercruiser mpi won't start - video

[Formulaz]

Anyone ever had a no start condition like this?
Already replaced-
Battery
Starter
Fuel filter
Spark plugs
Cleaned and checked ground
Same condition of battery voltage put to starter
https://vimeo.com/176046907

[tw_xi]

Did this just start out of the blue, or was something done and this started happening. It almost sounds like the timing has gotten changed, the plug wires didn't get swapped when changing the plugs?

[Formulaz]

Hey tw,
It started to become harder to start at the end of last year. I thought it seemed like a battery or starter. Bought a new battery for this season and it fired right up but during the first few rides it would start (not that easily) then kinda hesitate under load Around 2-3000 rpm.
I dismissed that as water in the fuel as it seemed to get better the longer the engine ran.
I took it out after that trying to burn as much fuel as possible at all attitudes to get rid of that potentially water in the fuel.
Meanwhile the starting issue developed like you see in the video and I ran the troubleshooting sequence which seemed to indicate a starter problem. So it was replaced.
And so this is how it remains


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[JCP]

Sounds like you have a cylinder or 2 firing early. I would double check the firing order of the plug wires as TW mentioned and if they are good, you could have a crossfire in the distributor, replace the cap, rotor and plug wires unless they are very new.

[Formulaz]

They (rotor cap) are fairly new (2 yrs?) and I will check for mis wiring but it's run well in this exact config so I can't imagine


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[Formulaz]

But I'll replace the cap and rotor. Good idea. Now that I think of it these caps were known for cracking and misfires weren't they?
Is there an automotive equivalent I wonder?


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[JCP]

I should have told you to try this first. Disconnect the coil wire and see if it cranks normal without the skip. If it still does the same thing your problem is not spark related.

[TeamAllen]

Have you checked the fuel pressure?

[Formulaz]

Ah yeah, good point.
I'm home from the lake now but I'll head up this week and try the coil trick.
And no I haven't checked the fuel pressure yet as I don't have a gauge. I can hear the pump run when you first turn the key and depressing the schrader valve does let fuel out under some pressure but I've no idea how much.


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[TeamAllen]

My EFI is TBI so I have a little different setup. I added a fuel gauge permanently. For your set up maybe something like this would work for you?
https://www.amazon.com/Caspers-10713.../dp/B0056VAC42
https://lmr.com/item/LRS-3280/Mechan...FQqLaQodIh8OAw
https://www.amazon.com/JEGS-Performa...242DBRXWFZXJA7

[cbath]

Have had 2 friends boats sound exactly the same with a no start. Both of their's were corrosion on the distributor caps causing spark to cross fire... I would suggest swapping out the cap and rotor.


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[Joehs]

Holy crap! Mine is literally doing this exact same thing and I am in the same spot you are. Replaced the batteries, replaced some wiring leads, replaced the starter (twice) and it's still doing this.

Batteries are good but I still can't get it to turn over. This just started out of the blue for me, was running 'well' up until it started. As I read the replies though, it seems that my 'well' might have been less than Ideal. My boat is fairly new to me (5 months) but has not failed to start until this problem came up.

I will replace the cap and rotor as well to see if I can resolve it. If you find a solution, PLEASE let me know as I'm struggling to find the correct answer to this.

Thanks!

[Formulaz]

Wow thanks for all the great response! I'll let everyone know as soon as I try anything else for sure


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[joaquin12345]

So mine did that two different times when I first got it. I took it out did fine turned it off then next time wouldn't start. It would almost start but just wouldn't. I checked everything you did. What I ended up doing was getting a flat head screwdriver and putting it on the throttle area so it would give it a tiny bit of gas. Well to my surprise it started but as soon as I took the screwdriver out since it was revving it some it would die. Felt like something was holding back the engine. I ended up taking the belt off and trying to spin the different components. Well when I got to the impeller housing it wouldn't budge. After taking off the housing and inspecting it somehow the fins on the impeller reversed out so that's what was holding the engine back on start up. Took it out put it in the correct way. Verified by hand that it turned. Hooked everything up and it started up. It was strange but that's what was and happened to me two different times. It's like when I killed the engine it made a slight turn backwards and caused this. I've read about it and has happened to other people. Just a thought since you have checked everything else out.

[hopps1945]

Interesting. Having the same problem with my 2000 2300V. I have a post on here from last year dealing with this. Came on late in the season for me. Replaced battery, plugs, cap, rotor, fuel pump, still have the problem. Have to open the throttle a bit to get it to fire. It will run rough for a short bit before it will idle out. Will pull my belt and check to see if there is any resistance on any of the pullies. Intersting to see what your fix is.

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