Thunderbolt IV ICM Conversion

[kwma01]

I have recently run into the issue of a bad Ignition Control Module on my 1996 5.7L Mercuiser Alpha drive. I have looked for a replacement and see that I can purchase them for around $450 which is so absurd that I can't bring myself to pay it. I have looked at converting to a Delco EST system which can be purchased for around $250 for aftermarket manufacturers on Ebay. I really would like to see if anyone has attempted to install the EST ICM on a thunderbolt distributor. The EST module has the timing curves set for the mercruiser and it is marine rated. I would think that it would only be a matter of making a pigtail to wire it into the system. I do not know if the hall effect sensor would be suitable for input or if the coil would have any issue but otherwise it should work.

I would appreciate any input from others that may have attempted this or have pertinent information on the subject.

Thanks
kwma01

 

[NHGuy]

I think if you post or search this on offshoreonly.com there's a guy on there who is very well versed in the various distributors and their wiring. I do believe you can do that as you are asking. At the very least he can let you know yes or no.

 

[kwma01]

Thanks for the lead. I will post a question there as well.

 

[alldodge]

Yes do search and ask on OSO and report back if it can be done.

I'm thinking it will not work because you want to use a TB4 distributor and the EST module, at least from what I'm reading. The EST needs to be set in base timing mode to adjust timing. The TB4 is just point and adjust.

 

[kwma01]

I found a new EST marine module on Ebay for $39. So I will do a little R&D when it comes in.