Mercruiser 5.7 engine died

[ted4420]

Newbie needs answers please! My neighbor asked me to look at his boat. He said it died on the lake. It is a Capri 2050SS with a Mercruiser 5.7 (looks like a small block Chevy. I will have more info. on it when he gets back home. I have tested voltage at the + terminal and have aprox. 12V. The ignition module is mounted on a brkt. on the distributor. I have read about the shift switch and would sure like to know why there isn't any spark. A wiring diagram may give me an idea how the system works. Maybe some testing procedures. Thanks, Ted

 

[wanna-be]

Re: Mercruiser 5.7 engine died

does the motor crank?

 

[ted4420]

Re: Mercruiser 5.7 engine died

The motor cranks and no spark. Ted

 

[Bt Doctur]

Re: Mercruiser 5.7 engine died

shorted tach, remove the grey wire fron the neg. side of the coli.
bad coil
module
dist sensor

 

[wanna-be]

Re: Mercruiser 5.7 engine died

1. ck the kill switch, lanyard may have gotten pulled; 2. ck wiring to kill switch; 3. ck high intensity wire to distributor; 4. ck voltage to coil (crank igntion)

 

[ted4420]

Re: Mercruiser 5.7 engine died

I am not familiar with boats. Where is the kill switch. There is 2 wires going to the - side of the coil. which one needs to be connected? Ted

 

[ted4420]

Re: Mercruiser 5.7 engine died

I have disconnected the tach. wire from the coil and cranked the motor and the motor didn't start. A few times the motor briefly started for a few seconds and then continued to crank and not start. Any ideas? How do you check the sensor and the module? Thanks, Ted

 

[dubs283]

Re: Mercruiser 5.7 engine died

download proper manual from adults only sticky at the top of the threads page and follow ignition troubleshooting guide. you will need a spark tester to perform the troubleshooting. the one page flow chart troubleshooting guide is quite helpful and easy to follow

 

[ted4420]

Re: Mercruiser 5.7 engine died

Thanks, I will look for the sticky. I did take the wires off the neg. side of the coil and used a jumper wire and briefly grounded it an saw a small spark on a spark plug connected to the coil wire. Thanks, Ted

 

[wanna-be]

Re: Mercruiser 5.7 engine died

"Where is the kill switch." typically below the throttle beside the driver seat.

 

[ted4420]

Re: Mercruiser 5.7 engine died

Bump

 

[Bondo]

Re: Mercruiser 5.7 engine died

Bump

Ayuh,.. Bump? Bump,..??

How about an Up-date,...
Did you download the manual,+ check the wiring diagrams,+ flow charts for igntion diagnosis,..??
How about the Vintage of this barge,...
With the distributer mounted igntion,.. It could be 1 of a couple...

A few times the motor briefly started for a few seconds and then continued to crank and not start. Any ideas?

That,... Sounds like you Found the Spark, but Flooded the motor...
Have you pulled the Sparkplugs to have a Look,..??

 

[ted4420]

Re: Mercruiser 5.7 engine died

I started a new post because I didn't think this one was posted. The engine starts and runs great! It than starts cutting out after about twenty seconds and the dies.I turn the key to off then try to start it again and it starts again and does the same thing. I have noticed that there are wires from the drive reservoir and 2 sensors that go to the ignition module. The problem started because of a empty drive reservoir. Tell me why these wires are going to the module. I down loaded the flow chart and the wiring diagram and followed them. Is this a engine shut down system? Thanks, Ted

 

[can-amsledder]

Re: Mercruiser 5.7 engine died

I started a new post because I didn't think this one was posted. The engine starts and runs great! It than starts cutting out after about twenty seconds and the dies.I turn the key to off then try to start it again and it starts again and does the same thing. I have noticed that there are wires from the drive reservoir and 2 sensors that go to the ignition module. The problem started because of a empty drive reservoir. Tell me why these wires are going to the module. I down loaded the flow chart and the wiring diagram and followed them. Is this a engine shut down system? Thanks, Ted

Because you are new to working on boats I have to ask, are you running water to outdrive while running it/trying to start it?


It almost sounds like it?s running out of gas. Fuel filter plugged??

 

[ted4420]

Re: Mercruiser 5.7 engine died

The boat is a 1996 or 1997 Capri 2050ss

 

[ted4420]

Re: Mercruiser 5.7 engine died

I am runny water to the out drive. Ted

 

[Bondo]

Re: Mercruiser 5.7 engine died

I turn the key to off then try to start it again and it starts again and does the same thing.

Ayuh,... Does this barge have an Electric Fuelpump,..??
There's an oil pressure Switch mounted portside, down low, just ahead of the oil filter boss....
Try By-passing it with a jumper...

 

[ted4420]

Re: Mercruiser 5.7 engine died

I just started the motor, After it died, I went back and hand operated the throttle and gas squirted out of the excellator ports.

 

[ted4420]

Re: Mercruiser 5.7 engine died

This motor has a mechanical fuel pump.The wiring diagram apears to have sensors that connect to the ign. module. Could someone shed some light on this? Thanks, ted

 

[Don S]

Re: Mercruiser 5.7 engine died

Go get a mercruiser SN of the engine block just above the starter and next to the flywheel cover

The engine starts and runs great! It than starts cutting out after about twenty seconds and the dies.

That is classic electric fuel pump problem with faulty wiring or bad oil pressure switch. I know you said it has a mechanical fuel pump in the Other closed thread, but your problem can't happen with a mechanical fuel pump.

So get a SN and check for a mechanical pump again.