1996 5.7 mercruiser Digital ignition gm not starting

[coltmanning]

I am at a loss here. I have a1996 Silverton with gm mercruiser 5.7 digital ignition. Boat set up for a while so I was told I needed to give it a tuneup. So I started off by by changing batteries since it was sitting for 3 years. After changing batteries motor would turn but not fire off. So I went a head an changed out the spark plugs and wires. Motor would turn but not fire off so i checked an was not getting spark. So I looked around an found the ignition module in side the distributor was done for so I replaced it replaced the rotor and cap. Checked it would turn but not fire off no spark so in my head hey it has to be the coil pack replaced it an bam it fired right up. But was running bad and back fireing. so I did I compression and a leak down test on it. Found number 4 and 6 numbers were bad. Was told motor ran fine and seeing it being sitting up thinking it just had a stuck valve. So I put some good ole Marvel mystery oil in there after a few times running it up and down the water it cleared up. Next day started up ran smooth so got out ran it down the river slowly adding speed to it. Got to the cove an turned the boat off and put some music on for the day while everyone was in the water end of day I hit the key to that motor batteries were dead. Other motor was running so while coming in I hit the key to see if the other motor charged the batteries it sounded like it was getting there so I waited. Hit it a few more times ended up burning that started up. I had that starter rebuilt since I could not find a 9 tooth starter anywhere. Got the starter back put it on i would hit the key it would turn an act like it wanted to fire up but nothing would happen. I looked at the key switch bc I would have to hit it a few times for it to do anything saw there was build up on the wires and then key switch it self so replaced key switch fixed wires and now motor turns every time I hit the key. But the motor will turn but not fire off now all the wires on the starter are on right. Batteries are good fuel is spraying right. Is there something I am missing I need to check?

 

[alldodge]

Need a motor serial number?

Also try breaking up your comment into shorter statements to make it easier to read

Being a 96 it probably has a TBV ignition. Here is the troubleshooting guide

 

[coltmanning]

Need a motor serial number?

Also try breaking up your comment into shorter statements to make it easier to read

Being a 96 it probably has a TBV ignition. Here is the troubleshooting guide

The serial number on the tag is L663222
Sorry I was trying to give full detail so people know exactly what has all been done an happen.

 

[alldodge]

Thanks for the SN, looks like you have TBI, MEFI-1 ECM and EST igntion

No problem with providing more info, its just it was all one paragraph. Just trying to read it was a bit hard due to structure

Check your fuel pressure, is it 30 psi?
If you have a NOID light (or can get use of one), could check that there is 12V on one side of the injectors with key ON. Then use NOID across the injectors to see if they are being energized

Are you getting spark?

 

[coltmanning]

Thanks for the SN, looks like you have TBI, MEFI-1 ECM and EST igntion

No problem with providing more info, its just it was all one paragraph. Just trying to read it was a bit hard due to structure

Check your fuel pressure, is it 30 psi?
If you have a NOID light (or can get use of one), could check that there is 12V on one side of the injectors with key ON. Then use NOID across the injectors to see if they are being energized

Are you getting spark?

Thanks I will have to get back to you with those answers next weekend.