No start after engine install. Need Help!!!

[jonny rotten]

Need help!! Video I pulled a motor 6 months ago for an oil pan leak. Was running perfect when I pulled it out. Kind of proud of myself for doing every single thing myself and now I might have to send this out over something simple. Won't even hiccup with ether. What I know: 12 vts at purple coil wire. I took a timing light and put it on the coil to distributor wire and got nothing. Coil has 1.3 primary 7.85 Secondary. Previously there was a jumper bypassing the oil sender/ switch (forget which one is which) I replaced both sender and switch down by the oil filer with new OEm parts. Now the oil pressure gauge is pinned and there is a constant alarm with key forward. Merc says there is an oil cutoff that kills power to coil?? I put the jumper back for testing and still had a no start with alarm. I have 9 volts at the blue wire at the push on terminal sender switch. I think I got all grounds. Shifter cables disconnected and cutout is centered. Lanyard in run position. I also disconnected bullets at shift Interrupter for testing at that did nothing. New cap rotor wires plugs...any help with this is appreciated. I'm Not great with electrical...really want to figure this out on my own and complete my project. Thanks

 

[Scott06]

Wi

Need help!! I pulled a motor 6 months ago for an oil pan leak. Was running perfect when I pulled it out. Kind of proud of myself for doing every single thing myself and now I might have to send this out over something simple. Won't even hiccup with ether. What I know: 12 vts at purple coil wire. I took a timing light and put it on the coil to distribute a wire and got nothing. Coil has 1.3 primary 7.85 Secondary. Previously there was a jumper bypassing the oil sender/ switch (forget which one is which) I replaced both sender and switch down by the oil filer with new OEm parts. Now the oil pressure gauge is pinned and there is a constant alarm with key forward. Merc says there is an oil cutoff that kills power to coil?? I put the jumper back for testing and still had a no start with alarm. I have 9 volts at the blue wire at the push on termininal sender switch. I think I got all grounds. Shifter linkage disconnected and cutout is centered. Lanyard in run position. I also disconnected bullets at shift Interuptor for testing at that did nothing. New cap rotor wires plugs...any help with this is appreciated. I'm Not great with electrical...really want to figure this out on my own and complete my project. Thanks

willing to bet during cranking you are loosing voltage, start with positive battery and ground cables.ther are 2-3 at the back on flywheel cover

Measure with a volt meter on positive terminal of coil while cranking should stay close to 12. Then go through the thunderbolt ignition troubleshooting guide in the stickies.
From what you are saying the coil is not firing? Willing to Bet missing a ground. Also disconnect the shift interrupt switch for testing

 

[Scott06]

Wi

willing to bet during cranking you are loosing voltage, start with positive battery and ground cables.ther are 2-3 at the back on flywheel cover

Measure with a volt meter on positive terminal of coil while cranking should stay close to 12. Then go through the thunderbolt ignition troubleshooting guide in the stickies.
From what you are saying the coil is not firing? Willing to Bet missing a ground. Also disconnect the shift interrupt switch for testing

the oil pressure alarm doesn’t interrupt the ignition. It just makes the buzzer go off when below 4 or 7 psi.

 

[jonny rotten]

Wi

willing to bet during cranking you are loosing voltage, start with positive battery and ground cables.ther are 2-3 at the back on flywheel cover

Measure with a volt meter on positive terminal of coil while cranking should stay close to 12. Then go through the thunderbolt ignition troubleshooting guide in the stickies.
From what you are saying the coil is not firing? Willing to Bet missing a ground. Also disconnect the shift interrupt switch for testing

Ok. I'll leave the shift interrupt connections off until I figure it out. There are 3 or 4 grounds on the port side engine stud in the back and one on the starboard side. I took pictures before I started. Those are all on. What ground would cause no spark at coil? Where would that be? Good to know the oil sender/switch will NOT cause a no start issue. I'll cross that off. I'll check the 12 volt at purple wire + while cranking and see what happens

 

[alldodge]

Something is not connected correctly
What is your motor serial number?

 

[jonny rotten]

Something is not connected correctly
What is your motor serial number?

0L072052...thanks

 

[alldodge]

Motor has TBV ignition

What I know: 12 vts at purple coil wire.

Make sure 12V remains when cranking and if it does
Run the TBV troubleshooting

 

[jonny rotten]

Motor has TBV ignition


Make sure 12V remains when cranking and if it does
Run the TBV troubleshooting

View attachment 407943

11.96 battery
Coil + 11.85 key forward
Coil + 9.54 cranking
After getting stuck last year I replaced the module in the distributor, then it fired right up. So that's new also

 

[alldodge]

Looks like you have corrosion and/or weak Bat, At 11.85 it's around 40% charged
Fully changed Bat is 12.7V

 

[jonny rotten]

I found this ground wire and couldn't figure out where it came from. It does have the same size ring terminal as the coil post. Is that supposed to go on the negative post of the coil? Not sure if the wire is even long enough to reach coil. I put it on the starter solenoid bracket. It was NOT there before I started looking at an old pic. It comes out of the harness where the starter solenoid wires come out

 

[jonny rotten]

Looks like you have corrosion and/or weak Bat, At 11.85 it's around 40% charged
Fully changed Bat is 12.7V

In the video you can hear it cranks really strong. Does the drop from 11.85 to 9.54 on the coil when its cranking tell you anything?

 

[alldodge]

In the video you can hear it cranks really strong. Does the drop from 11.85 to 9.54 on the coil when its cranking tell you anything?

Yes it says there is corrosion and the ignition is not getting enough power

Take voltage readings at Bat post

 

[alldodge]

Don't know where the wire goes to but black wires should be grounds

 

[jonny rotten]

Yes it says there is corrosion and the ignition is not getting enough power

Take voltage readings at Bat post

I did. I posted it with the coil numbers. Battery is 11.95
How does the main module on the riser ground? Is that though to the riser or within the wiring harness? Could that be a potential issue?

 

[alldodge]

All grounds should be well grounded. Don't know if the bracket were the black wire is connected has a good ground or not. The wire might be for a Mercathode which doesn't look like there is one,

What we know
Voltage is low
There is no spark

Need to run through the TBV troubleshooting

 

[jonny rotten]

All grounds should be well grounded. Don't know if the bracket were the black wire is connected has a good ground or not. The wire might be for a Mercathode which doesn't look like there is one,

What we know
Voltage is low
There is no spark

Need to run through the TBV troubleshooting

The only problem with that is it starts with tach wire which is taped into the entire wiring harness from the engine to I assume the tach. I would need to take the whole thing apart which seems like it could cause more problems for potentially nothing being the engine ran fine before. I used Deoxit on the grounds, power at starter, electrical connections ETC trying to do it right. Deoxit supposedly is good stuff for electrical connections. I'll charge the battery but feel like thats not it. I've started engines with way more dead batteries.

 

[cyclops222]

I am great at taking apart anything.
Put it back together perfectly ? Most times.

 

[Scott06]

The only problem with that is it starts with tach wire which is taped into the entire wiring harness from the engine to I assume the tach. I would need to take the whole thing apart which seems like it could cause more problems for potentially nothing being the engine ran fine before. I used Deoxit on the grounds, power at starter, electrical connections ETC trying to do it right. Deoxit supposedly is good stuff for electrical connections. I'll charge the battery but feel like thats not it. I've started engines with way more dead batteries.

Disconnect the tach wire (grey) at negative post on the coil. This will remove any chance the tach is killing the spark

you can also disconnect it and check for continuity to ground with a volt meter.

woukd agree battery and connections both positive and negative are suspect given the voltage drop

 

[alldodge]

The only problem with that is it starts with tach wire

What???
The motor "Starts" with the Tach wire???

 

[Scott06]

What???
The motor "Starts" with the Tach wire???

The TB troubleshooting guide starts with verifying the tach wire isn’t shorted to ground …