Hi, I just recently disassembled my 95 civic si engine bay completely for paint put it back together reinstalled the engine and went to fire it up. First few times main relay was clicking and I just wasn't getting spark. So I swapped out a known good distributor and still no spark. Started checking my grounds and looking everything over I went to cycle the key again and now I have no spark of fuel....main relay is not working. I am getting power to fuse 31 at both sides of the fuse with the key on or off. Fuse 24 gets power with the key on and fuse 18 has power when cycling the key. Now I have power at pin 1 and no power at pin 7. And if I jump pin 5 and 7 with the key on the fuel pump will run. Also when I first put the key on the check engine light stays lit solid as if it is not reading my ecu at all. I'm out of ideas I've done everything else I can think of!!! Please help

 

Is the G101 thermostat ground disconnected?

If you jump pin 1 to pin 7 in the main relay connector, does the fuel pump run?

 

Yes the go 01 is good I sanded and checked it 5 times..and if I jump 1 and 7 no it will not prime with key on or off. Only 5 and 7.

 

This^ is the problem. Voltage from fuse 31 is not reaching the main relay connector.

 

So what would I do from here easiest way?

 

The problem could a bad hood fuse box or a bad wire from fuse 31 to the main relay connector.

 

Which is crazy also because I have power at the fuse 31 on both sides but no power at all to 7. So I'm guessing there is a break or burn in the wire somewhere. Can I just run a wire straight from the under hood fuse box to pin 7 and be good or does it t off and shoot different ways?

 

Again, the hood fuse box is bad or the Yel/Wht wire that runs from connector C205 on the underside of the fuse box to the main relay connector is broken. You can use a multimeter to distinguish which is bad.

The wire goes from C205 to pin 1 of the main relay connector, not pin 7.

 

Got you. I have power at pin 1 though with the key on. What should I be testing with a multimeter exactly. Not to familiar with the electrical side of things I just know what's what generally. Never seen this happen before. Thank you for any detailed help you can give me

 

Unplug the main relay connector.
With key off, what voltage to body ground do you measure at pin 1?
With key in ON(II), what voltage to body ground do you measure at pin 5?

 

I called it quits for the night and ran out of diesel for the shop to keep warm lol. Thanks for all your help I will post my results of those 2 wires tomorrow!

 

Ok so I did the test I'm getting 9.41 with key off on pin 1 and 12.11 with the key on (II) on pin 5. And I tried jumping 1 and 7 again and still won't fire the pump. Where should I check nexr

 

^Low voltage at pin 1.

What are the voltage to body ground readings at both test tabs of fuse 31? Compare them to both readings at fuse 24.

 

With the key on or off?

 

12.63 on both sides at fuse 31 key off and 12.29 one side and 12.31 on fuse 24 with key on

 

Okay, the low voltage is not caused by a damaged fuse 31.

To determine whether the problem locates within the hood fuse box or the Yel/Wht, you need to disconnect the battery, remove the hood fuse box, and unplug connector C205 from the underside of the fuse box and the main relay connector.

Then do these two Ohm tests:

1) Measure resistance between one of the fuse 31 tabs and the pin on the underside of the fuse box corresponding to the Yel/Wht wire.

2) Measure the resistance between the Yel/Wht wire pin in C205 and pin 1 in the main relay connector.

Post the two Ohm readings.

 

Ok i did all that and tested the yel/white pin and the top of fuse 31 and got 1.2 on one side and 1.4 on the other side. For the second test though im a bit confused...By the pin in the main relay connector you mean disconnect the main relay on the floor in the car. Then test it from c205 yel/white wire thats underside the hood fuse box then stick the other end in pin 1 on the plug on the floor in the car?

 

I stuck a wire in pin 1 because my multimeter doesn't reach by doing that and did what I thought u meant and it came back 0.2 not entirely sure if I did that correct or not bare with me I'm in the multimeter learning phase. And I really appreciate all your help

 

Post a picture of your multimeter showing the setting you used for the Ohm tests.

The Yel/Wht wire also can be Ohm tested by grounding the appropriate C205 terminal to the (-) battery post and then measuring resistance to body ground at pin 1.

 

 

If I just replaced the wire from underside of fusebox, the yellow/white one and went straight to pin 1, will this solve my problem??

 

The multimeter setting looks good.

Only if the wire rather than fuse box is bad.

 

And u don't think a bad ground would x a use that wire to just not a signal or a weak one...i mean it was priming just fine. Then just stopped lol I'm going to run a jumper over there on the outside of the car for ***** n giggles and See if I get power before I go tucking it in and make it look all pretty. Thanks though I'll keep you updated I hate looking through forums and when people fix the problem never post there solutions lol

 

I haven't seen you post anything to suggest a bad ground. Stay focused on the low low voltage to pin 1.

 

No luck at all I killed both of what was suggested to be the problem...i changed the under hood fuse box and the yellow white wire over to pin 1 and still constant cel and no fuel pump prime....smh. I don't know what else to do. I even tested pin A26 and b2 for grounds and it's getting perfect ground.