Mercruiser 5.0 MPI 2013. Crank but no start.

QBhoy

Fleet Admiral
Joined
Mar 10, 2016
Messages
8,348
Keen to hear what this is. Must admit. Reading just the first post...screamed of the usual battery not 100% issue that mpi are well known for. As in...perfectly healthy cranking...but starter taking the power enough for the ignition system not to want to try to fire...until the key is let go of...then for a second, she’ll give a kick trying to fire.
But it seems there may be other issues too.
 

Hiecke

Seaman Apprentice
Joined
Feb 21, 2021
Messages
40
It doesn't make since. A motor needs air, fuel, spark and compression to burn fuel. If compression was low the fuel would still burn, just not very well

Was spark checked with spark gap tester on plug wire ends?

If so I got nothing
 

poconojoe

Lieutenant Commander
Joined
Sep 10, 2010
Messages
1,966
Fixed!

it was the key switch!
Many many thanks to all.
Wow! That's great and a very inexpensive repair too.
Sometimes it's just something simple. A key switch, a tether kill switch.
That stupid tether switch got me once. I don't have the lanyard attached to it. I never use it. I was out on the water... it cranked, but wouldn't start. Luckily I flipped around with that tether switch and it fired right up. It must have gotten bumped when we were hanging out. Live and learn...
 

isaacs

Petty Officer 2nd Class
Joined
Oct 15, 2013
Messages
153
Fixed!

it was the key switch!
Many many thanks to all.
I was going to suggest putting a jumper between the battery positive and your coil--that would have put you on the right track because it would have run perfectly. I keep a jumper wire tucked away in my engine compartment just to get me home in case one of the many items between the dash and coil were to fail. Lanyard switch, fuel cutoff, oil pressure switch, shift interrupt switch, lots of wiring and connections--it's amazing these things run at all!
 

Hiecke

Seaman Apprentice
Joined
Feb 21, 2021
Messages
40
Yes, it has spark, fuel pressure, injectors. It was a weak connection with the key switch.
 

Fun Times

Moderator
Staff member
Joined
May 16, 2009
Messages
9,126
Distributor assembly is/was dry inside? Any signs of water on the ignition coil?/General area? or at the ignition key switch itself?
Fixed!

it was the key switch!
Many many thanks to all.
Thanks for the update...Finding issues like this is generally just part of taking your time of doing a really good visual and physical touch of the components for loose wiring and corrosion, etc. etc... Glad you found and were able to fix it.(y)

:sneaky:Oh and you know this same thing could happen to an outboard too...:D
 

Hiecke

Seaman Apprentice
Joined
Feb 21, 2021
Messages
40
The gremlim is alive.
The rust of the distribuitor is attracted to the cmp sensor and the signal fails.
It happens when Mercruiser uses car parts in marine engine…
 

Hiecke

Seaman Apprentice
Joined
Feb 21, 2021
Messages
40
Im here again. The gremlim is alive.
New distribuitor, coil, driver, cmp, ckp sensors, spark plugs.
No beeps.
After change the distribuitor, the rotor burns.
Could be the spark plug wires?
 

QBhoy

Fleet Admiral
Joined
Mar 10, 2016
Messages
8,348
The gremlim is alive.
The rust of the distribuitor is attracted to the cmp sensor and the signal fails.
It happens when Mercruiser uses car parts in marine engine…
What does this mean ? Is there something plugged into the distributor ? Any I’ve seen don’t have anything plugged into the socket on the diz. Mine defo doesn’t
 
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