4.3 engine wont start

[alldodge]

For me Scott is saying, you can get the TB5 module kit and it will plug directly into the connector which connected to your TB4. There will be no need to replace the distributor, add/splice new wire or two.

 

[achris]

Let's walk before we run... Let's PROVE that module faulty before splashing that sort of cash....

Chris....

 

[Gerhard Peters]

So is the TB5 module kit a replacement for the TB IV? Or what is the difference between the TB5 and 4.3L Delco Voyager EST Marine Distributor Kit?

 

[Gerhard Peters]

Let's walk before we run... Let's PROVE that module faulty before splashing that sort of cash....

Chris....

Ok, what else is there to test? I have followed the "Testing Thunderbolt V Ignition System" guide

First off I have a weak spark so it is not an issue of not having a spark at all

When following the testing and get to:

Unplug WHT/RED bullet connector from the distributor.
Check for 12 volts on lead coming from module.

I have 0 volts. According to the testing I have a bad module

 

[achris]

So is the TB5 module kit a replacement for the TB IV? Or what is the difference between the TB5 and 4.3L Delco Voyager EST Marine Distributor Kit?

Yes...

TB-V is far superior to the Delco... Far superior. (Even TB-IV leaves the Delco for dead)

Also, with the Delco, you'll need to do quite a bit of rewiring... Despite what Delco say in their advertising, it's not 'plug and play'....

Chris....

 

[Gerhard Peters]

So where can I get the TB-V? Do I have to replace the distributor as well when going with the TB-V?

 

[achris]

Ok, what else is there to test? I have followed the "Testing Thunderbolt V Ignition System" guide

First off I have a weak spark so it is not an issue of not having a spark at all

When following the testing and get to:

Unplug WHT/RED bullet connector from the distributor.
Check for 12 volts on lead coming from module.

I have 0 volts. According to the testing I have a bad module

Something else is going on. If you had 0 volts on the white/red wire, then you'd have NO spark.

Check you keep full 12v on the coil postive when you're checking for spark. Or run a wire directly from battery positive to coil postive (make sure it's big enough)... Also, make sure you've disconnected both the tacho feed (grey) and the shift interrupt switch wires...

Also check ALL the ground wires.

Chris....

 

[achris]

So where can I get the TB-V? Do I have to replace the distributor as well when going with the TB-V?

TB-V module is from a Merc dealer and it just replaced the TB-IV module. Uses the same distributor and sensor as you already have....

Have you read my document/explanation on the Thunderbolt system?

Chris....

 

[Gerhard Peters]

I have two grey wires from the coil negative. Which one is the feed?

 

[Gerhard Peters]

Have you read my document/explanation on the Thunderbolt system?

Chris....

Yes more than once. I noted/quoted that diagram before already. That is when I started asking about the grounding. Now I grounded the ignition module as you noted before and still the same results

In your explanation of the Thunderbolt system you noted

All the different modules do the same job. They are supplied by a 12 volt wire, usually purple, via the positive terminal of the coil. They supply a current controlled 12 volts for the sensor (located inside the distributor)

I do NOT have 12 volt on the white/red wire going to the sensor inside the distributor.

 

[Gerhard Peters]

Chris,
I did as you suggested. 12 volts directly from the battery to the + (purple) on the coil and disconnected both the tacho feed (grey) and the shift interrupt switch. Still the same result. Very weak spark

 

[alldodge]

TB-V is far superior to the Delco... Far superior. (Even TB-IV leaves the Delco for dead)

Opinion by iboats member

Also, with the Delco, you'll need to do quite a bit of rewiring... Despite what Delco say in their advertising, it's not 'plug and play'....

Not really, small amount of rewiring, my opinion

 

[achris]

Opinion by iboats member

Not really.
Does the Delco have adaptive timing? No.
Does the Delco have idle control? No.
Does the Delco have provision for knock control? No.
​​

Not really, small amount of rewiring, my opinion

Not a small amount. My experience.

Chris...

 

[alldodge]

Your funny

 

[achris]

Your funny

I do my best.

 

[Gerhard Peters]

I was hoping someone would be able to help instead of being funny :laugh:

I called a local marina for the Thunderbolt V and they quoted me $900 Canadian dollars

Before paying that I would rather buy the Delco kit. As long as it works and I can have my boat on the water I don't care which system I have

 

[alldodge]

Sorry, we just have different opinions. In short either will work.
The EST was used for many years after TB was stopped, and then Merc went to HVS which IMO is crap, but is also irrelevant in your case

I see your module as bad and you need a fix. Have not heard if achris agrees it needs replaced

 

[Rick Stephens]

I lost the Thunderbolt IV module in my boat and without a look back installed the Delco EST unit. Took an hour or so of wiring and resetting timing following different procedures. Never had a problem since. Works perfectly and runs great. Beat hell out of trying to find, and pay for, a Thunderbolt module.

 

[Gerhard Peters]

I ordered the Delco EST. Found it online for $294 + shipping

Thanks for all the help everyone!

 

[Scott06]

I ordered the Delco EST. Found it online for $294 + shipping

Thanks for all the help everyone!

That will work for you just pay attention to shift interrupt wiring in instructions. Where stock merc grounds the coil out to cut spark, delco puts 12v positive to distributor to effect the same. Per ricks comments experince and support is here if needed, even if they are trying to be funny...oh wait they did help you while being funny.