Poor Man's GT40 Diagnosis

Could we add part Numbers to the spreadsheet. Like for the eec relay. That is the same relay for the fuel pumps Right?

Cool, thanks

Updated Spreadsheet

While I'm sure CC used a varied PCM tune, I highly doubt they reinvented the wheel with the components and sensors. You should be able to scan these in much the same way you would scan its automotive variant. That being said the gt-40 is a super common engine and has several forums dedicated to it that have thousands of problem/solution threads. The majority of issues you would have on the boat version are probably well covered and common in the automotive forums. All we'd need to do is gather that info and put it over here.

To me pre obd-2 systems were always iffy on codes, I always had better luck finding someone with a related problem then breaking out the ohm meter to check the component that solved the problem.

That being said I think you're table is a good idea, gives people a quick list of common issues/solutions to check.

My idea for this thread is to have a place to summarize common GT40 problems and their solutions. Each Problem-Fix combination will be one datapoint. That way, there is a running reference. This would not be so much a place to ask questions, but a place to post the fix and a link to the thread where the problem was resolved.

My thinking is that the diagnosis for these motors is a little trickier, since they've moved beyond traditional tuning, but scan tools can be a little expensive and obscure as well. I'm going to attempt to update and re-post the following table as time goes on. I can also add/modify the problems and add new fixes as it becomes necessary.

Just because a problem has a found fix once, doesn't mean not to post it again. I'm hoping to come up with a true data table, that will show the probability for each fix. Here is my blank slate:

GT40 Spreadsheet on Google Docs