Greg_MB

I have searched for threads with the same issue, but mine might be a slightly different problem than others, so here it goes:

Car is a 1995 Civic CX with B16 swap. Car had no issues until I pulled the dash out and removed the pad that lines the firewall. Now the car won't start.

- Starter cranks
- CEL solid, connect the service jumper, and stays solid
- No clicks from the main relay, fuel pump doesn't run

Unfortunately, my shop manual is elsewhere until this weekend, so I'm hoping Honda-Tech can help.

Here's what I've tested so far.

Main relay:

- Same symptoms with two different main relays
- 12.5V on Battery, using main relay ground (KOEO)
- 12.5V on Ignition with key on (II)
- ~10V on Starter with key on (start)
- Fuel pump runs, injectors click if the battery and fuel pump terminals are jumped
- Both main relays click on bench test

ECM:

- No voltage at A25 or B1 with KOEO
- Very little voltage (0.02~0.04V) at A25, B1 with key on (II)
- Battery positive to A24 shows good grounding
- Battery positive to A23 shows no voltage
- B9 has good voltage on key (start)
- Hondata won't recognize/connect to ECM
- Same symptoms with another known good ECM

All ECM-related fuses look good, test with good resistance

I'm thinking A25 should show 12.5V, but it doesn't. Just fyi: car has a Rywire mil-spec b-series wire harness, and I've checked all the connections and they look good.

Thoughts?

vtakej

Maybe you pulled a connection out when you pulled the firewall lining. Not sure what it could be though. I would just start looking around at everything.

Former User

Check whether 15A hood fuse 31 is blown.

4d96gsr

It's gonna be ur ignition fuse check under the dash fuse I forgot the name of it but it's a fuse under ur dash

4d96gsr

It says acg (s) on the fuse diagram size 15a

Former User

Yeah, it's either 15A dash fuse 24 (acg) or 15A hood fuse 31 (ECU/PGMFI).

Greg_MB

Thanks for the replies.

Still no luck. All the fuses are good. ECU under hood (15A) was singed on the side closer to the windshield, but still tested good. Replaced just to make sure; still won't power ECU at A25 with the key on (II). I'm pretty sure the low voltage at A25 I sometimes see is just bleed from neighboring pins. Pulled the dash out again, and can't find any loose connections. Fact is, a CX with a Rywire harness doesn't have a ton of connections...

Anybody have a test procedure for the ECM harnesses? I've ruled out the main relay, so what else could prevent the ECM from getting power?

skuded

check to make sure all your pins in the ecu connector are fully clicked into the connector and they didnt get pulled out a little while you were working around it, also are you sure you dont have fuel pressure, and have you checked for spark? i would pull the under hood fuse box out and look under it and make sure all your wires are still in tact under there, and have you checked the ohms in the wiring going from your ecu to your ignition, check to see if you have high resistance in any wires, and just for grins have you hit the left lower side of the dash while cranking the car just to see you it would be a possible bad connection in the pgmfi relay, and im not sure on a 95 model but make sure the clock works with the ignition on, on some of them the clock is on the same circuit with the pgmfi relay

Greg_MB

SOLVED:

Vibration working on a zip tie wedged behind the blower sawed through the wire that goes from terminal 6 on the main relay to B1 on the ECM. Repaired it and the car started right up.