Intermediate Short 90 hp to Tohatsu

Hello, that's for the Add.
I have been helping a older Friend out with his 2003 90hp Tohatsu. The problem is it has a short in the engine somewhere but not all the time. I have ran it on earmuffs for over an hour and never blow the 25amp ignition, Ecu, oil pump Fuse. Then next time it blows the fuse put a new one in and it start right up. Yesterday I ran it in the water and same thing ran blow fuse ran again, also while this is happing the Ground wire from the Air rail to the block turn red hot and burnt into just before the fuse pooped. Also I noticed that after the fuse blow once the engine acted like it was not running on all cylinders, then the next time back to full power.
So after all that does anyone have a suggestion to help me pin point this problem?

Thank you

Assuming the model is MD90B.
What errors does the ECU show?

pvanv said:

Assuming the model is MD90B.
What errors does the ECU show?

Click to expand...

Yes it is an MD90B, I apologize for not stating that up front.

how do I pull the code on this model? And if it is blowing the fuse to The ECU do you think a code still will be present?

Get a Factory service manual (not an aftermarket manual) from your favorite dealer. The codes and their interpretation can be extensive, so you really need the manual.

Clearly, something is drawing a ton of amps to both cook the air rail ground, and to blow the fuse.

When did this start happening? Did anything unusual precede the problem?

Other then the Local shop the Gentleman to it to, and charge $3500 for a major tune up and a week later $1500 to change out one injector, nope it started this after he got it back. He did take it back once more but it sat there at the shop for 6 weeks and said he had other customers and didn't have time to look at it..

Go back and get your moneys worth