superslinky

I am working on a 96' Honda Civic for my friend. With the key in the on position, main relay doesnt kick off nor the fuel pump or injectors. injectors spray engine full of fuel. main relay and computer are good, and main wiring harness has been changed. with injectors unplugged fuel pump still wont turn off. it is a d16y7 by the way.

Former User

The ECU is bad (providing constant ground to A16 ECU terminal that activates the fuel pump) or the wire between the main relay and the ECU A16 terminal is damaged and grounding out.

superslinky

Thanks for your comment. I just replaced engine harness that runs to ECU and main harness has already been changed both harnesses are good because they came off a running car. I also changed crank sensor today. Now I really don't know what to do and its aggravating me.

Former User

1) Turn the key OFF and disconnect the connector to the main relay.

2) Turn the key to ON(II) and then measure the voltage at terminal 2 of the connector to body ground (see diagram below). Do you measure any voltage?

superslinky

ok, i just got back from checkin the plug and #2 (blue and white) terminal had nothing, with key on or off, in all three positions. there was only 2 other wires that had voltage. on your diagram the ones that had voltage where, #5 and #7.

Former User

When the key is turned to ON(III), does the starter crank the engine?

Does the fuel pump run continuously only when the key is turned to ON(II)?

superslinky

with the key in the on II position the fuel pump and injectors run constantly. one more turn from the on II position which is III the engine cranks, and fuel pump and injectors still run while cranking. should the blue and white wire have voltage? can i test this by running a wire from the A16 ecu plug to the #2 blue and white wire located on the main relay plug? or is that a dumbass question resulting in a fried ecu? so many questions, but you are helping tremendously. i mean i have wired up resistor boxes, vtec and several other things, but this is a problem i have never delt with before.

Former User

The blue/white wire should only register battery voltage when the key is turned to ON(III), so the test you did yielded the proper outcome. That ruled out the possibility that unexpected power from the blue/white was causing the fuel pump to run continuously. In addition, detection of voltage at position 5 and 7, but not others, was also proper.

At this point, I think there could be three different causes:

1) A bad main relay (you can test it)
2) A bad ECU inappropriately providing constant ground at terminal A16.
3) The ECU is receiving an incorrect signal from the crank angle sensor circuit in the distributor indicating that the engine is turning.


When you turn the key to ON(II), does the CEL remain ON or turn OFF after 2 seconds? If it remains ON, can you pull any codes when you jump the service connector?

superslinky

1) A bad main relay (you can test it)
2) A bad ECU inappropriately providing constant ground at terminal A16.
3) The ECU is receiving an incorrect signal from the crank angle sensor circuit in the distributor indicating that the engine is turning.

#1 and #2 is ruled out. But #3 is a possiblity. Yes the CEL stays on. It will not let me run a diagnostics on it, it just shows up error. With the key in the on (III) position (cranking) should the blue and white wire have power? Is there any way I can check the A16 terminal, and if there is can you send me a diagram of the ECU pigtails? I had a diagram but I lost it and I can't remember what site to go to and recieve it..

Former User

Yes, the blue/white wire should have power when the key is turned to ON(III).

Are you able to start and run the engine?

superslinky

No, the engine will not start and run. I think due to someone else working on it and fouling the plugs cause engine is full of fuel including mixed in the oil. i just checked the blue and white wire while cranking it and it did have power.

Former User

Yeah, the engine sounds flooded. You should drain the oil and refill with new oil to see whether the engine will start. This will help with the troubleshooting charts below:

superslinky

ok thanks. i will study this and get back with you.

superslinky

i fixed it to where i can read codes now, but there are no codes showing up. wtf. idk.

crxboy909

there is probably a wire running direct from the battery to the car... cause thats how mines was when i first bought it

superslinky

are u talking about from the positive side, grouding out on the car?

Former User

What was the causing the inability to pull codes?

Does the CEL remain ON steady with and without the service connector jumped?

Do the fuel pump and injectors still run continuously?

superslinky

im not exactly sure the reason of the inability to pull codes, cause i done several different things that day, including changing the distributor. yes the cel is still on bright and yellow as it can be. no codes are yet to be pulled. i did try unplugging the fuel pump and then plugging the injectors up, and the injectors still run until all fuel pressure is exempt from the fuel lines. i think im goin to just scrap the piece of ****!

Former User

At this point, my guess is that your ECU is bad. Why don't you believe this is a possibility?

superslinky

i put the computer out of my running car into this car with the problems, and still the same thing. i kno, im thinkin the same thing, wtf. i did talk to a very well educated mechanic i have known for a while today. he said it makes no sense also, but he did say he would contact his friend at honda for further info. i will keep you posted on this issue.

Former User

Have you done any of the electrical troubleshooting from the diagrams in post #12? For example, unplugging sensors to test whether the CEL turns OFF:

superslinky

yes i tried that, cel still stays on. the owner of the car came and picked it up and is taking it to somone else, honda i think. although he is supposed to call me and let me know what the problem was, if it can be fixed. i think the s.o.b is haunted. as soon as he lets me know what it was or is, i will let you know. thanks for all your help.

Former User

Good luck. I'm interested to know how this turns out.