94 Honda civic lx no power to fuel pump

Ruben6805

New Member
Car started one morning then just turned off, cranked again and ran for about 30 secs then shut down. i tested main relay and it was bad, bought new one and even tested the new relay, and its good. Car still wont turn on. checked fuses and are good. checked fuses 31 and 24 and good. checked power at fuel pump and dont get any voltage. did a continuity test from neg terminal of fuel pump harness to body of car and get continuity, making me think that the ground wire is ok. used a jumper wire on main relay plug from 1 to 7 and pump turns on. also used a jumper on 5 to 7 on main relay plug and pump turns on. other thing im thinking is the ECU. Please help me.
 

RonJ

Banned
Have you cleaned and tightened the G101 ground on the thermostat housing?

When you turn the key from off to ON(II), does the CEL turn on and stay on? If so, jump the service connector, to see if any codes are found. Or does the CEL just remain on steady after jumping the service connector?
 

Ruben6805

New Member
I do not hear it prime when I turn the key on. When I jumped it with the jumper wire I did hear it prime
 


Ruben6805

New Member
I read about the thermostat housing, but I'm not sure how to do this, can you explain it to me?
 

Ruben6805

New Member
Sorry, I'll double check the light today, I know it comes on when I first turn the key to on, but didn't notice if it goes off. I'll check it today. As far as the priming, it primed when I jumped the wire on the main relay plug, but not when the relay is on normal.
 

Ruben6805

New Member
So I checked the CEL before I left for work, I turned the key to on (II) and it comes on, after I left it like that for about 2 minutes it continues to stay on. When I get off of work, I will jump the service connector. From what I read, it's under the glove compartment and I can use a paper clip to jump it. Is this correct?
 

RonJ

Banned
Ruben6805 said:
So I checked the CEL before I left for work, I turned the key to on (II) and it comes on, after I left it like that for about 2 minutes it continues to stay on.
Click to expand...
This is progress and useful information.

When I get off of work, I will jump the service connector. From what I read, it's under the glove compartment and I can use a paper clip to jump it. Is this correct?
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Remove the passenger kick panel that covers the ECU. The service connector is located above the ECU and branches from the wire harness. It's a 2 pin/wire connector. Click the Codes link in my signature and read about the CEL there.
 

jameswanser

Member
Registered VIP
5+ Year Member
hate to say it, but if pump ok, main relay ok, and fuses ok, it likely IS your ECU. I had same issue happen 7 or 8 years ago with my 92. If you can borrow a known good ECU from a buddy, try swapping it out and see if pump works. IF it IS the ECU, at least it's not a p28. the ECUs for the LX are about $50 at the yards around here
 

RonJ

Banned
jameswanser said:
hate to say it, but if pump ok, main relay ok, and fuses ok, it likely IS your ECU. I had same issue happen 7 or 8 years ago with my 92. If you can borrow a known good ECU from a buddy, try swapping it out and see if pump works. IF it IS the ECU, at least it's not a p28. the ECUs for the LX are about $50 at the yards around here
Click to expand...
As our Civics get older and older, bad ECUs are definitely more common. If the OP has a known good ECU available to test, then such a swap is definitely worth a try. If not, then it would be prudent for the OP first to do more testing to rule out many other possibilities before buying an ECU.
 

RonJ

Banned
Here are diagrams that will help you locate the G101 ground wire attached to the thermostat housing. Remove the ground bolt and use a wire brush to clean it as well as its attachment site on the thermostat housing.

Also remove 15A hood ECU fuse 31 and 15A dash fuse 24 and replace them with new fuses.

When you have done these^, check to see whether the engine now starts and runs.

 

Attachments

Ruben6805

New Member
Ok so I jumped the service connector and the CEL just stayed solid. The SRS however did blink. I did notice yesterday the back up fuse 7.5 was blown and I did replace it. I replaced bothe the other 15 amp fuses as requested and cleaned ground wire that is connected to the thermostat. And still nothing.
 

Ruben6805

New Member
Question: I have a 95 Honda civic lx, that is standard as well, can I use the ECU off of that one to test my car to see if mine is bad?
 

RonJ

Banned
Ruben6805 said:
Ok so I jumped the service connector and the CEL just stayed solid. The SRS however did blink. I did notice yesterday the back up fuse 7.5 was blown and I did replace it. I replaced bothe the other 15 amp fuses as requested and cleaned ground wire that is connected to the thermostat. And still nothing.
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Recheck whether the Back Up fuse continues to blow. When it does, it clears all codes from the ECU. Therefore, you can't currently be sure whether some codes were thrown.

And yes, you can try the ECU from your 95 Civic for test purposes.
 

Ruben6805

New Member
So the fuse is good (7.5) but car still not starting, any ideas? CEL is on from key off to on (II).
 
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