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Discussion Starter #1
Hi all,

Ive searched and searched but cant seem to find the answer. I have a crank no start issue, i was putting in kill switches for my 91 civic hatch with a d16a6.

I cut the pin 8 at the main relay (a12, 14) and soldered it into a switch i also had the Fuel pump, GND, and B+, added to a switch. my issue is now my fuel pump wont kick on unless i GND pin 8,

Ive been going in circles with this is there any way to test that the ecu is shot?
 

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Pin 8 (a12,a14) is the ground trigger from ecu to turn the main relay on.

How did you hook it up to a switch?
 

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Discussion Starter #3
i tapped into the 2 wires and wired it to ground.

the 2 wires the come from the ecu doesnt put out a ground signal now.

I was wondering how to test this id rather have pin 8 hooked only to the ecu.
 

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So you wired a12 and a14 to ground?

To test to see if the ecu is putting out ground on a12 or a14 use a test light or multi meter. Hook one end to battery power and the other end to either a12 or a14 and turn key on. The meter should show voltage and test light should light for 3 seconds.
 

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Discussion Starter #5
also would it be better
1. to tap into these wires and give it a ground
2. bypass these wires and give the relay straight ground without the ecu wires?
3. Tap the ignition power to the fuel pump pin

just trying to figure out if my ecu is bad or i have another issue.

all fuses check out ok, also when giving the main relay ground at pin 8 i am able to start the car and drive it.

not too concerned for the bypass if it is the ecu and wont damage anything else as i will be swapping out this motor here in the next few months along with a new ECU.

Thanks!
 

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You shouldn’t be tapping anything. You need to cut the wire and put the switch between the wire you cut.

I don’t see how the ecu went bad unless you gave it power to something that should get power.
 

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Discussion Starter #8
Ok so I was going through this junction connector o was putting in between the switches and the main relay and I found that a few connections are joined together not as I thought it was just a wire for wire connector..
So now I see that the B+ I took to the connector and then I took the pin 8 also and it seems that power got joined to the pin 8 so therefore I sent power to pin 8 and the ecu.

Since this has happened is there something internal on the ecu that would of popped that I would be able to desolder and replace?

I guess I was trying to out a connector in series to be able to disconnect and make cleaner but it backfired.
 

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Discussion Starter #10
I'm not doing because I want to, I'm doing it cause I messed up the ecu I think and it's not giving a ground to close the main relay to provide power to the fuel pump. If I don't ground out the relay to close the circuit to give power to the FP I wouldn't be able to drive it.
 

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sounds like you blew your capacitors in the ECU. Need to remember that these ecu are getting old and any sort on uncontrolled power surge will cause the capacitors to go out.

I had the same problems, turned out to be main relay caused my Ecu to fry causing fuel pump to not prime etc and engine not to fire, it would crank byut had no spark.

I cut out old capacitors, soldered in new ones ( cost like $8 ) and works perfect.

If you need any ECU let me know. I have p28, po6 multiple of them.
 

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im telling you, Main relay is shot, and possible capacitors in the ECU its self.

Best to buy new ECU or change them out with new capicators.

I had the same demon when building my car.

I tried 2 different relay switches, nothing.
Changed out capacitors, worked then didnt
Used my boys relay and virgin p28 and everything good under da hood
 
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