Removing old Thunderbolt ing for new

P

Prostjim

Member
Joined
May 19, 2014
RO Number
33628
Messages
11
Has any one removed there ign and installed a aftermarket unit. I done with the thunderbolt. It starts right up when cold the as soon as it's hot won't or very hard to start. Last time out just shut off. So I'm looking to install a aftermarket maybe Davis HEI type system. Has anyone done this or any other switch with good success? Thanks Jimmy
 
Are you sure it's the ignition?
I have TBIV on all Plain Vanilla's 3 572 cu in blown engines with no problems whatsoever.

Maybe you have a carburetor issue leaking gas into the manifold? Maybe some vapor-lock? Nad grounds?

Send me your email addy - I can send you some troubleshooting guides for TBIV and V.
 
I was also wondering why you came to the conclusion that your problem is the ignition or even electrical. I think it would be prudent to isolate the cause or if you have, tell us what it was.
Lots of us RO's like to fix things rather than replace things willy nilly. (Gee, that's the first time I ever used that phrase)[:I]
 
Well today a mechanic came over and found broken and some burnt wires. After changing all this new dist with module and rotor,new ing amplifier, started right up adjusted the timing and as soon as it got hot won't start. The gas has been in there since last year and I can honestly say I don't know if it had stabilizer in it. Also new plugs and cap and rotor also. Any suggestions? Fuel pump has 6 lbs of pressure. And when it's cold starts right up. And also a new Msd black coil. Thanks Jimmy
 
He says that's the coil he uses all the time and no problems what's so ever.
 
TB ign doesn't use a resistor. It runs on full 12V. If that coil has an internal resistor, that's one of your problems.

If the problem isn't a bad coil or alternator, it's gotta be fuel related. What's the time frame between start-up and engine quit. Is it always the same?

Check your oil. Check engine temp.
 
No not really same time. I did pull the alt couple weeks ago and took it to get checked and they said it was charging ok. This is driving me nuts. I have another alt that I could put on that I know is a good one. Once it gets hot it won't start. Sometimes it sounds like it wants to start. But doesn't. Then kills batt. We did put volt meter on it when it wouldn't star yesterday and it read 12.8 at the coil.
 
And when it won't star and I look in the carb I have a squirt of fuel every time I hit throttle. And even sprayed a little starting fluid and nothing. No start. Thanks for trying to help. Jimmy
 
First, where were the burnt wires and what were they connected to??

FIND OUT ABOUT THAT COIL!!!

You have to help with responses to our inquiries. An internal resistor in the coil will get very hot and quit in a thunderbolt ignition system.!!!

Testing a cold alt for charging only tells you only that it's charging when cold. Swapping out the alt is a good start in eliminating possible causes.

...and we need to know about the burnt wires.
 
Primary side should be between 0.6 and 0.8 ohms

Secondary side should be between 9,400 and 11,700 ohms.
 
The two ground wires on the ing amplifier were a little burnt and the plug was broken and the amplifier was also broken. Let me know if there is anything else I should be telling you. Thanks Jimmy
 
Burnt wires in and around the ECM means there's a short somewhere....or maybe the alternators voltage regulator isn't working right.

The thunderbolt ignition system works great once you have it set up right.

The modules can go bad, too. I've had to replace mine and I got a couple extras with different advance curves. Depending on the model, Some advance can't be set at the '3000 RPM' mark. The advance curve is built in and can't be adjusted.

You'll have to review the specs on different modules. It's been a while since I did. The model number is on the lower corner. There's a number which indicates the total amount of advance built into the module. say it has a 24. Set the modules advance of 24* plus 6* to get a total advance of 30* at 3000 RPM. This will give you an initial (idle) advance of the 6*

Total advance is set at 3000 RPM
A total advance of 28* is for 87 octane
Total advance of 30* is for 89 octane
Total advance of 32* is for 91 octane

These numbers are for naturally aspirated engines with 9:1 compression or less.

This site may give you a little more info in the TB ign system though they have some timing number off.

http://www.marineengine.com/boat-forum/showthread.php?416610-Thunderbolt-IV-replacement
 
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