blaze_125

Terminal 8 to body : 6.84
A7 to body : 6.84

Looking like it's the relay doesn't it?

Former User

Fuse 31 -> main relay connector terminal 1 -> main relay -> main relay connector terminal 8 -> Grn/Yel wire - A7/A8

The low voltage problem is currently pinpointed to the main relay or main relay connector terminal 8.

blaze_125

Should I try bypassing the relay and see where it leads me?
There is a bypass "discussed" in one of the links you provided in another thread:
http://techauto.awardspace.com/mainrelay.html

Remove relay, and jump 1-3-7.

So either my re-soldered connection on the board is crap, or the prong sticking out of either end(relay or harness) is bad? I get continuity because there actually is continuity, but something makes bad contact and limits the voltage throughput?

Since I have the same problem with 2 "good" relays, I'm tempted to blame the harness prong that connects to Terminal 8. I'll take that one out and make it new again.

Former User

I have the same hunch.

blaze_125

those connectors are usually a pain in the b*tt to remove from the plastic holder without destroying the whole thing, is there a "trick" to do it nice and easy?

Former User

I don't know. Maybe someone else can chime in.

blaze_125

I was able to get the connector out of the plastic peice. I took some elbow grease but it got out. Since I had the hole empty in the holder, I connected the main relay to the harness(with empty #8). Since there was a hole where #8 used to be I was able to stick the probe of my multimeter on the prong sticking out of the relay... guess what... the reading was 6.84. So that rules out the connecter I removed from the plastic holder... Current comes out of the relay at 6.84 instead of actual battery voltage.

It looks more like bad relays now.
Anyhow, I got a parts car sitting in the driveway so I got a 3rd relay I can test tomorrow. I just did all the soldering on it and it's ready to be tested.

Former User

Excellent detective work. It seems the main relay is indeed the problem. You sir are a bona fide troubleshooter -- so much more elegant and less expensive than replacing parts at random.

Former User

By the way, a fully charged battery typically has about 12.5V, so your battery may be low on charge. Does it labor to crank your engine?

blaze_125

With all the testing and start try I have done within the past week, the battery is indeed undercharged... I brought in a powerpack today, and some booster cable just in case I need them.

So here is today's update.
I connected the 3rd relay and got a reading from the Terminal 8 directly on the terminal prong(not on the harness), and it gave me the same reading. All 3 relays give me exacly the same reading on terminal 8(so that rules out a bad connection within the relay). If a bad connection within the relay was the culpit I'd be getting different readings on each relay and I'm not.

At lunch time I'll put back the new wire between terminal 8 and A7/A8, and boost the car. We'll see where that leads me. Would a slightly drained battery keep the pump from priming? I mean it's not like the battery is reading 6v at this point, it's still a strong ~11.5 and doesn't have issues cranking.

Former User

I learn something new everyday. Apparently, the service manual is in error. It is actually correct to measure less than battery voltage at terminal 8, so this is not your problem. There is a voltage dropping resistor between main relay terminal 1 and terminal 8. It's explained here:

http://www.tegger.com/hondafaq/mainr...ion/index.html

and in the diagram below.

Time to regroup. So, at this point, you have identified two problems: (1) ECU terminal A7 has constant voltage rather than transient 2 second voltage and (2) the fuel pump does not prime. I think the first step is to fully charge the battery and then to re-examine both of these tests.


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blaze_125

I just went out there and here is how it looks...

I parked my other car beside, got it running and ran the booster cable to the Delsol.
Still no start, still no fuel pump priming.

Replaced the entire length of wire going from Terminal 8 to A7/A8.
Still no go.

Removed the relay, jumped pins 1-3-7. No start. I can hear the pump running, but still no start.

I'm still confused about a constant voltage between A7-A23.
According to the chart(page 11-118), while the motor is not running, I should only get current for 2 seconds. I get constant current.

blaze_125

I have a feeling I should investigate terminal 3 and whatever is on its line.

1 thing I should mention... When the relay is connected with terminal 8 connected as well, I can here the relay click when I probe #8 with the multimeter.

Former User

Former User

Terminal 3 tested fine because you measured battery voltage at A25 and B1. Do the test I mentioned above. I think you have an ECU ground wire problem.

blaze_125

I'm not really due for a smoke yet, but I'm thirsty and the cafeteria is "somewhat" on my way to the car... so brb lol

Actually, before I go, should I disconnect the A7 wire from the ECU and connect it to chassis for ground?
It's easy to do now since it's my own wire.

Former User

Haha...either disconnecting the wire or leaving it connected should work. If grounding it triggers the fuel pump to prime, then the ECU almost certainly has a ground problem (ECU connector terminals A26 and B2), consistent with CEL code 0.

blaze_125

A7 to body ground made the fuel pump start.
So now where do I start to check the continuity between ecu and whatever?

blaze_125

I guess this should be a good start?
Too bad I have little idea what I'm looking at lol

Former User

Good.

Turn the key OFF. Disconnect ECU connectors A and B. Test for continuity to body ground individually from terminals A26 and B2 (edit: in the ECU connectors). There should be continuity.

blaze_125

There is no continuity to any of the pins.
I didn't pay special attention to A26 nor B2, but I put my black probe on a ground location I know is good, and I slid the red probe back and forth on the ecu pins and never got a single beep.

Former User

You tested terminals in the ECU connectors A and B, right? The vast majority of ECU connector terminals should not have continuity to body ground. You need to specifically test A26 and B2. A26 pins to a Blk/Red wire, and B2 pins to a Brn/Blk wire. These wires run to G101 and should have continuity to body ground.

Also, do these terminals in the connector and ECU look damaged?

blaze_125

lol
I tested the pins directly on the ecu, not the terminals in the pastic holder...
I'm'a do it right when it stops pouring out there.

Former User

If A26 and B2 do not have proper continuity to body ground, then the solution to your problem is obvious -- repair broken wire or run new ground wire to the thermostat housing.

If A26 and B2 have proper continuity to body ground, there are several other possibilities that should pinpoint the problem. Just hang in there because you are now close to knowing the solution.

blaze_125

As easy as cutting the Blk/Red and Brn/Blk wires and run new ones?
Do they have to run to the t-stat housing? Are those the only 2 wires that connect to that ground location?

******
edit:

G101 seems to be fed from 4 locations...
2 black wires to later become 1 wire.
1 blk/red and 1 Brn/Blk that later become 1 wire
Making it 2 connectors on the G101 ground location.
******

I ain't givin'up. There is a fresh set of Azenis on that car that I haven't been able to fully exploit yet.