Bad ecu?

94 Civic EX, b18b1 Ls swap, p75 obd1 manual ecu

So with my first issue I posted on reddit, but things got more complicated so i知 coming here.

Original:https://www.reddit.com/r/ProjectHondas/s/wmXAcErRet

So, my original post was regarding an injector issue, and so after swapping injectors around I believed it to be a problem with the wiring, so I did these test according to the honda manual.

1. Injector voltage, all read 12 V

2. Use Noid lights to confirm if the signal is firing, all blinked normally.

3. Check continuity from the ECU to the injector harness, all were continuous.

After everything checked out I felt it was my ECU ( P75 obd1 manual) so I unplugged the ecu and took it in my house so I could inspect it more, and visually it looked fine.

Day or two goes by, and I plug the ecu back in, and now all of a sudden i知 at a crank no start, no spark. I致e confirmed i知 getting fuel, I took off the injectors with the tail, and visually confirmed all fire. So then I ground both the coil plug by itself, and then with the spark plug attached, and no spark. Now I replaced my rotor/cap pretty recently, and im 99% sure my dizzy is in working order. Bear in mind the car was driving absolutely perfectly without any hiccups prior to this whole situation.

So now i知 here, I知 placing my bets on something with the ECU being wrong. I have an s300 v3 on a p28 coming in soon, and plan to load a base map on that and see if it works. Though now i知 asking does anyone have experience with a bad ECU or similar symptoms ?

I bought this car used and molested so it has its fair share of quirks, and I got an opinion from a tech from honda who said it probably is the ecu as when you plugged it back in it fried something, but what would cause that? The only thing I could think of is that in the back-up fuse which is supposed to be a 7.5 A, is actually a 10 A fuse, but i can稚 speak on whether that matters or not. So i壇 like the opinions/advice from some others. Thank you

 

It's an old ECU. One of the resistors or diodes may have failed. Remove the cover and take the board out to inspect.

 

Have done that, and visually everything looks fine but I have heard that sometimes things can fail without any visual evidence

 

correct. They do not have to have burnt marks to be bad.
Sounds like bad components on the board. Have you tried using another (non-VTEC) ECU??

 

I would if I could, but no one I know has a spare lying around, though I ordered a p28 with s300 v3, and i was hoping that it should start up if i put a base map for a b18 non vtec.