Troubleshooting lean condition on turbo H22

[Raf99]

Well....... picked up the ECU.

...
...
.... and started looking at it. This poor ECU, I'll never buy a ECU from the company that sold it to me again. (*cough* HAMoto.....*).




Let's look closer
...
..
....hmm crusty pins? and ..... slagż?..


Using too much heat when soldering (too big of a tip)


hmmm.... this is how a water damaged PCB usually looks. But why mine?





This ECU I never opened as it would have voided the warranty. The first one we had to send back as it wouldn't connect to SManager. There were always issues with dealing with the company I bought this from. And now that I've finally opened it, wow! This board has 'too much heat', not enough solder, "slag" on the tracers, appearance of water damage.... .. just wow. Yet the car ran fine for two years.

So... I cleaned up the board. And now the part you'll like....

The ECU works now. (not a good sign, but.... let's see what happens here)

Took the phone along for the first start...



So we went from this......... cowboy, circus show, wtf battery, who the what


To this. Graph is stretched out a bit but ... more stable. Everything is more stable. The initial lean condition when returning to idle is normal. The .25 mark is what we are focused on. I'm ok with this, although the car shutters like it's sick at this moment.




But......... there is bad news. The ... issue ... is ... still ... present. UG.

As the car sat at operating temps and things started to heat up and the "recovery" at idle suffered worse and worse....

So over the course of 30min or so...

1.

2.

3.



Cell phone vid - It still like to dip into lean a few seconds after returning to idle for no reason. Sometimes it lingers there too long and the car shakes.



And all of this changed because I scrubbed the board with alcohol and a toothbrush and did the capacitor kit on it.


So........ ya. Still need another ECU to test. Doh. I'm almost starting to think about the main relay now too...

[Raf99]

So cleaned up the ECU, re-soldered the joints. Cleaned and checked the thermostat ground. Checked the fuel pressure at idle and revving, its fine. Car starts and runs fine. Today I took her outside and gave her a bath, let it run for 30min while I washed her. Ran fine until it got hot. Lean at idle, backfiring and shit on off load.

And it's crazy, the symptoms are identical to day 1. It sat there and started to blip and blop eventually. I said fuck it and took her for a drive. BAD idea! Didn't take 5min and she was not happy. Came back home. It's like anything and everything I've done to fix this has done shit all. Still looking into a new ECU. This is her when i got home. Pegged at 17.1, worst I've ever seen it. Running like shit.




I see the problem here already. So at this point I'm going to start focusing on the power connections.

[Crankshaft]

I call Witchcraft on this Bro, this whole ordeal is making me doubt whether I should keep going on with mine.

[sonikaccord]

Yo, check your 5 volt output from your ECU. I wonder if your sensors are getting proper voltage.

[Raf99]

Yep. Agreed with both of ya. But let's keep in mind I haven't sent this to a professional yet. So this is just me trying to learn. This type of witchcraft is caused by a bad ECU or power related issues. And i'm starting to get pretty pissed off with all of this. So I'm going to start "reversing" things here. But I think I know what's going on here.

I kept thinking that the problem was the car going lean the hotter it got. Thinking it was heat related. In reality I think it's losing battery power over time. Although after a drive the battery voltage is good (12.5V) the datalogs show different.

Here is the car idling over a long period. Although I read 13.6V at the battery with the car on you can see over a period of time the voltage is dropping.


Here is me driving down the road and wow... @ the battery volts. So we have obvious power issues while driving and at idle. The longer the car drives the worst the battery level gets which causes these issues ( I think ).



So moving forward I'm going to try:
- ditch fuse box extension and move fuse box back to engine bay if needed
- determine why S300 shows 11V sometimes when driving and stop battery voltage from dropping. It seems that there's a difference from what the battery shows for voltage (car on/off) and what S300 is reading.

If after this there is still an issue, I'll order a new ECU.

[sonikaccord]

Also some more things to note.
- shouldn't the duty cycle increase to reduce the AFR? It seems like the ECU isn't even trying to bring it back down.
-this happens only when the engine rpms are returning to idle. It's like the injectors decide to cut off during engine deceleration. Can you do another log and put the cursor where the AFR starts to shoot up?

[Raf99]

Well..... spend a couple hours today messing around with this. But i could not make it "mess up" like it was doing yesterday. My theory is that the fuse box extension has something to do with all this, but in the past I had moved it back and had the same issues. BUT.... i didn't leave it there for long. Just long enough to see that i had the same issues. I think the ECU has to re-learn closed loop as well and I didn't take into consideration that over time the battery voltage being supplied was dropping.

So I took some numbers, graphs with the fuse box in the back and in the front: (1-4 , different data logs, and time passing...)

fuse box in front
1- 13.96V
2- 13.29V
3- 13.38V
4- 13.58V

fuse box back seat
1- 13.58V
2- 13.19V
3- 13.19V
4- 13.10V

It seems that with the fuse box relocated to the rear the voltage just slowly keeps dropping. While I trust my electrical work in the fuse box extension there is a charging aspect or voltage supplied to the ECU aspect I'm not understanding here.

fuse box in front / all warmed up:


fuse box in the back / all warmed up:


In our manual the ALT has it's main power connection. There are also wires for:

White/Red - To fuse box #15 (main power wire)
White/Green - To ECU
White/Red - To ECU
Black/Yellow - under hook fuse box
White/Blue - Inst cluster/Int.Control Unit/ABS



"A common misunderstanding is the battery supplies normal running load power. This is not correct, the alternator normally supplies all electrical energy. Of course the alternator will not support the electrical system when the engine is off, when starting the engine, and under certain operating conditions of extreme electrical loads, especially at slow engine speeds. The battery supplies power any time the alternator is unable to support the full electrical demand. The battery kicks-in instantly, even if needed for a tiny fraction of a second, because the battery directly parallels the alternator's output. "

My setup on the left. OEM on the right.


In the OEM setup the alternator is pushing power out to the battery and also to the fuse box as it supplies the main power for all accessories. What I am thinking is that the 4AWG wire I'm running from the ALT to the circuit breaker is not adequate enough. Assuming one took the starter out of the above picture running around 25' from the battery to the ALT should be all 2AWG. I'm not certain if that wire step down is causing my issues or not. The ALT is a 90amp ALT, so assuming it's max output is 90amps then 22' is the max. I think this is the bottleneck.



Besides all this ..... the next plan of action is to move the fuse box the front and take it for a drive. See how she reacts in open loop.

[Raf99]

Also some more things to note.
- shouldn't the duty cycle increase to reduce the AFR? It seems like the ECU isn't even trying to bring it back down.
-this happens only when the engine rpms are returning to idle. It's like the injectors decide to cut off during engine deceleration. Can you do another log and put the cursor where the AFR starts to shoot up?

I'm thinking injectors are cutting off because they don't have enough power/voltage being supplied. Thoughts?

Still want a graph?

[sonikaccord]

I like this graph more. If you could get one with S.Trim, Batt, AF, TPS, RPM, I think that would tell us a lot.

At 0:14 you give the car a quick blip of the throttle, the AF shoots straight up, batt voltage seems to be decent...not enough to really cause any issues under a no load situation like this, but pay close attention to the S.TRIM here.

If the ECU senses a lean condition, the S.TRIM line should go up, irregardless of whether the injectors are working or not. The S.TRIM shows how much more or less fuel the ECU WANTS to give to the engine. This line is flat here, like it doesn't care or doesn't see the lean condition.


Your next throttle blip has a lot going on. At 0:29, your AF goes down and your S.TRIM goes up AND your BATT takes a dive. When your S.TRIM returns to normal, your BATT goes back up and the AF skyrockets!

At 0:33 you seem to give it a little bit of gas, but check out what happens after that. Your S.TRIM goes wayyyy up, BATT goes wayyyy down, AF is steady?? Dafuq??

At 0:41, it looks like you release the throttle and everything goes to normal, well not normal but the original failure condition.

At 0:47, you press and hold. This is where it contradicts the previous timestamp. Your S.TRIM rises, your BATT is constant, and the AF falls like a brick!

If you could grab another one like this, that would be awesome! I think we can get some answers.

[sonikaccord]

I'm thinking injectors are cutting off because they don't have enough power/voltage being supplied. Thoughts?

I don't think so as this only happens when the engine is returning to idle. When the rpm is constant, everything looks fine and that would require more power than idling. The injectors, ECU, and ignition is on the same line (I think), so I'd think that other issues would be present.

Actually, in the graph I posted two posts up, you can see the BATT is stable, but yet the issues are still happening. We may need longer logs as well. Maybe 1500 rpm hold, slow increase and slow decrease in rpms and an idle hold.

[sonikaccord]

In the OEM setup the alternator is pushing power out to the battery and also to the fuse box as it supplies the main power for all accessories. What I am thinking is that the 4AWG wire I'm running from the ALT to the circuit breaker is not adequate enough. Assuming one took the starter out of the above picture running around 25' from the battery to the ALT should be all 2AWG. I'm not certain if that wire step down is causing my issues or not. The ALT is a 90amp ALT, so assuming it's max output is 90amps then 22' is the max. I think this is the bottleneck.

Besides all this ..... the next plan of action is to move the fuse box the front and take it for a drive. See how she reacts in open loop.

Let's do some math here.
A 25' run of 2 AWG has a resistance of 0.0039075 Ohms
A 25' run of 4 AWG has 0.0062125 Ohms

At 90 Amps:
The 2 AWG would have a drop of 0.351675 Volts
The 4 AWG 0.559125 Volts

That is assuming a full run of 2 or 4 AWG with your car pulling 90 amps for a long period of time. Now keep in mind that 90 amps at 13.5 V is 1215 watts. Your car should not be using 1kw to power the ECU and related engine electricals or to even charge the battery unless it's completely dead.

The alternator will not put out full amperage under normal operation, unless you have a few amplifiers that you have on max volume.

[Raf99]

Let's do some math here.
A 25' run of 2 AWG has a resistance of 0.0039075 Ohms
A 25' run of 4 AWG has 0.0062125 Ohms

At 90 Amps:
The 2 AWG would have a drop of 0.351675 Volts
The 4 AWG 0.559125 Volts

That is assuming a full run of 2 or 4 AWG with your car pulling 90 amps for a long period of time. Now keep in mind that 90 amps at 13.5 V is 1215 watts. Your car should not be using 1kw to power the ECU and related engine electricals or to even charge the battery unless it's completely dead.

The alternator will not put out full amperage under normal operation, unless you have a few amplifiers that you have on max volume.

Agreed, any thoughts on why we are slowly losing voltage over a period of time when I use the fuse box extension? (wires are proper AWG, etc.)

[sonikaccord]

so I Took Some Numbers, Graphs With The Fuse Box In The Back And In The Front: (1-4 , Different Data Logs, And Time Passing...)

Fuse Box In Front
1- 13.96v
2- 13.29v
3- 13.38v
4- 13.58v

Fuse Box Back Seat
1- 13.58v
2- 13.19v
3- 13.19v
4- 13.10v

It Seems That With The Fuse Box Relocated To The Rear The Voltage Just Slowly Keeps Dropping. While I Trust My Electrical Work In The Fuse Box Extension There Is A Charging Aspect Or Voltage Supplied To The Ecu Aspect I'm Not Understanding Here.

agreed, Any Thoughts On Why We Are Slowly Losing Voltage Over A Period Of Time When I Use The Fuse Box Extension? (wires Are Proper Awg, Etc.)

It looks like both configurations are losing voltage. Are you using the ELD input on the ECU?
Here's a link to bypass the ELD:
https://www.hondaaccordforum.com/for...-bypass-32726/

[Raf99]

It looks like both configurations are losing voltage. Are you using the ELD input on the ECU?
Here's a link to bypass the ELD:
https://www.hondaaccordforum.com/for...-bypass-32726/

Hey, I appreciate the input. I can get you any graph you want, it's just a view. ELD is disabled. I can give you my datalogs if you have SManager.

I'm so lost, fack. And I hate it! I hate not being able to troubleshoot my own car! / rant.

So from here on out I'll keep the fuse box in the OEM location to complicate things less. But to re-cap a bit:

- New alternator
- New yellow top battery
- New ECT sensor
- New capacitors in ECU
- Checked all grounds
- No other electrical issues, or any other issues at all

Took the car for a drive today. No lean conditions which puzzles me. All was fine, left the driveway, drove 5min down the road and turned around at a store. As soon as I pulled in the parking lot and was off throttle/on the brakes/turning, the car stalled. No lean conditions though, but still a big disappointment.



This was the original issue. I moved the fuse box and it was stalling at stop signs + going lean. So I'm thinking the lean is due to the power issues. But I still cannot explain the stalls. It's like I need ELD, yet the car ran like this for 2 years. The whole car wants to die when you are off the gas and on the brakes.

Anyways, pulled into the parking lot to turn around the rpms dropped to 200, then 100, then 0. Battery dropped to 5.8V!! wow! I know the car stalled but I think the battery dropped to 5.8V before the stall, not sure on that as the car was still moving when it stalled. I never let the rpms drop again on the way home, I kept throttling it until I got home, even in neutral. When I got home I was off the gas & on the brakes trying to make it stall. RPMs went down to 200 and it almost stalled, but picked itself up. I bet if I was steering while doing this it would of died.

I'd like to say it sounds like the ELD needs to be enabled, are the brake lights load on the car causing it to stall? But the car ran fine for 2 years with this setup

End of the run. I'm not seeing any reason for this battery fluctuation.



I'm fresh out of ideas on this. Let's keep in mind I haven't changed anything with S300, just moved the fuse box back and throwing new parts at it.

[Crankshaft]

Check for corrosion on ground and power cables, i know it can cause weird symptoms and it would make sense to build up over time.