Hi Guys,

Recently I just repaired my engine (D16A9), got a new crankshaft, bearings, rings, belts, oil pump. I had an issue before with the main relay and it killed the ECU so I had to get a new one too. The car didn't start at all after we tried to do it several times, we checked the timing, we tested my ECU and distirbutor on another car, we also checked the voltages and grounds on the ECU and the internal lines and everything seems ok. We checked the check engine and it is giving the ecu error code but as stated before, it worked perfectly on another Civic. Perhaps any of you has an idea on what should I check?

 

Hello,

What is the code number? And are you missing spark, fuel, or both when it comes to starting the engine?

 

Code number was 1. The original ECU was a P29 but now I have a P75 with CobraRTP (if that helps). Both spark plugs and fuel pump are working well

 

Ahh if the ECU isn't the same as OEM, I'll let someone else chime in. However, if you have spark (at all four cylinders) and good fuel pressure, that means the reason the car won't start is either a lack of compression or no injector pulse.

 

I can't imagine the main relay destroying the ecu. It is only responsible for sending battery voltage to the ecu. It's not regulated down to 5v or anything, sending 12-14v is normal. So I'm hard pressed to imagine how you burned it in that way.

Sounds to me like the original ecu was probably fine. Sounds to me like the main relay needs fixed by resoldering the joints inside (super super common).