Have an 89 civic with a d16y7 swap that was running fine until recently. Ecu fuse underhood had popped, replaced that. Now the fuel pump wont run unless i wire power directly and it only fires if i spray fluid into the intake, so i assume injectors arent getting power either. Please help.

Edit: i need to add more info. I checked all other fuses. They are good. I could only find a 4 prong relay under steering column hanging and it does not click when key is turned. But does click when i apply 12v directly to it. Not sure if this is the main relay? From what ive seen it is supposed to have more connections.. check engine light is solid, but it was like that before..

 

Definitely sounds like your main relay. It’s under the little cubby where you would put change. Under the dash. Get to it and make sure there is power running to it and pop the cover off of it and check for any bad solder joints. You can resolder them or get a new main relay for 70 bucks at garbagezone

 

If you have a good phone camera, take a pic of the solder points on the main relay and zoom in.. I recently fixed mine by re soldering them and the pic makes it easy to see the broken ring at the base of the solder against the board.

 

I tested the main relay and main relay harness and both checked out according to steps given here and still no luck.. just cranks, no fuel pump priming or pump coming on. But when tested in steps, the pump turns on.. https://honda-tech.com/forums/honda-...-pics-2535047/

 

Im wondering if the ecu is bad.. engine is d16y7 with y8 intake and p28 ecu.. is it possible its bad yet still get spark but no fuel pump or injectors working? Main relay and its harness is good and passed all testing..

 

If your check engine light is solid, check for codes.. there's a reason why the fuse popped and would point to a sign of a wire short. Wiring can be such a pain.. even though you tested the main relay, I would still pull it out and open it and check the solder points just for ***** and giggles. Since your ecu fuse went the problem is most likely somewhere else.
I think it would be odd if your ecu was the problem if it has never been opened and modified.

 

I cracked the relay open and everything looked good. Cannot say the same for the ecu.



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To my understanding the mod in the last pic is for changing auto ecu to work for the manual..
Going to see about repairing the broken bits..but havent been able to find a schematic for the p28 board.
Any ideas?