96 Accord Hydrolocked with fuel & no ecu connection
 

Hello, new to this site but not new to working on my daughters 96 accord 4cyl (non VTEC). Had a cel code I pulled with the egr insufficient lift and I had cleaned the ports 12 months prior. I was doing some egr checks with a 12v jumper and a vacuum gage when I made a terrible mistake.

I accidentally put the 12v jumper on the outgoing egr plug positive terminal. In another words I put 12v to 12v and engine immediately died. When I tried to restart and turn engine over the cylinders & intake filled up with gas. It was totally locked so I pumped all the gas out of everything then went to check fuses and found someone had put a 30 amp fuse in a 7.5 amp ecu spot. Right then I knew it had fried something somewhere. Hooked up my torque pro and it said no connection to ecu. I also have no fire and of course the injectors just let the fuel pump spray gas right on through.
Can someone give me a little help!? I can't find a good diagram to help figure out what controls what and where I need 12v or ground. Changed out Ecu and it didn't change a thing.

Which fuse box had the 30 amp fuse inserted instead of the 7.5? Is this the backup/radio fuse? Does the 7.5 amp fuse keep blowing?

What wire color did you accidentally jump with 12V on the EGR valve?

Thanks so much for asking and sorry for the late return. Working overtime has kept me from the garage and computer.

The 30 amp fuse was inside the interior box @ the drivers kick panel. The ecu and back up radio at the underhood fuse box is fine. There is 11.8 volts to both underhood fuses.

I accidently touched the yellow/blue + wire on the harness side. It no longer has any outgoing voltage.
The black/yellow at the Egr control box has 11.8 volts.

I'd suggest testing all of the fuses.

That yel/blu wire is the 5V reference voltage for the throttle position sensor. Does the TPS yel/blu wire have a 5V reference?

What was the honda part number for the PCM you replaced?

It has BA7 on one side and 37820-POB-A70 881-118097
I pulled it from a wrecked 96 lx that was running when parked. The one I took out of my accord has the exact #'s .

The yel/blue at the EGR (the one I touched 12v to) has zero volts and also the TPS yel/blue has zero volts.

The zero at TPS may explain the injectors filling cyl?! Doesn't the pgm-FI relay lie in between the 2 fuse panels and ECU?
I will check incoming current on fuse terminals & ohm check fuses as well tonight. Will get back to ya.
Thank you for trying to help!

Something is drawing the current for the 5V reference signal from the ECU. I suspect the wiring got damaged when you supplied power and you will to trace down where the 5V signal is lost in the wiring. This will be a bit tedious.

The 5V comes from D10 on the PCM, goes through C352/C134 out of the main wire harness on the driver's side of the engine bay, then through C267/C129 on the passenger side of the engine bay. I attached some pics.

Unplug C352/C134 on the driver's side of the engine bay and verify the yel/blu wire in that connector has 5V on the PCM side of the harness. Do the same with only C267/C129 unplugged.