Bank to Bank Injector Base Pulswidth difference in open loop

[joecar]

What is patina/deposit on injectors...?

Spark plugs #3, #7, #8 seem to show evidence of oil/carbon... #4 shows something deposited on ground electrode.

I read something that indicated PCM can use rear NBO2's for trimming in some very special cases when front NBO2's could not be used... I would disconnect all the NBO2's and see if this improves the situation.

[DrX]

Lots of carbon/oil on many pistons as well. Not sure if deposits on injectors are from leaded race fuel. #3 injector is strangely clean. No rear O2s are present. Pistons 3, 7, 4 are pretty wet with oil and a lot of carbon buildup. Don't recall what # 8 looked like. Tried a cylinder balance test and 5,7,8 didn't seem to have any effect on the AFR on their respective banks. #8 seemed to have some effect after I played with some tables.

Compression test:
1-192 re-tested the same on second round
2-165
3-170
4-155 first round, 165 after a squirt of oil
5-160
6-170
7-165
8-160


Leakdown:

1- 20
2- 20
3- 12
4- 12
5- 18
6- 18
7- 15
8- 20

1-20____2-20
3-12____4-12
5-18____6-18
7-15____8-20

[joecar]

Hmmm, not good.... compression test does not agree with leakdown % indicating there are multiple problems... what do cylinder bores and valves look like...?

[DrX]

Definitely multiple issues now. Many valves have thick carbon on their tops just as the pistons.







This piston is different:


Looks like that material can be scratched off:




Looking through an injector boss into an intake port:








Few more in a slideshow

[DrX]

Had the ID1000 injectors flow tested...looks like they didn't appreciate being cleaned. The automated test is a gradual ramp up.




So static(max) flow rates for the ID1000s were:

Initial/After 2 cleaning cycles

1. 864/888cc/min
2. 852/876cc/min
3. 864/888cc/min
4. 852/888cc/min
5. 852/876cc/min
6. 876/900cc/min
7. 852/888cc/min
8. 864/864cc/min

With 2 and 6 being erratic. Not sure why #3 was clean as a whistle(see pics) compared to all the rest. Wiring checks out good to all injectors.

What I had noticed was that bank 2 would tend to go way lean on a heat-soaked idle. Cold testing doesn't tell me how the injectors behave at higher temps.

[joecar]

Hmmm... hot soak idle B2 goes lean... and no front NBO2's (are they absent or present disabled...?)... is wire harness ok...?

[DrX]

Hmmm... hot soak idle B2 goes lean... and no front NBO2's (are they absent or present disabled...?)... is wire harness ok...?

I have run both no O2s and O2s present but disabled. To confirm what my widebands were showing with no narrow bands present, I actually installed a pair of new narrow bands. They also showed bank 2 going lean as the intake heated up(still in OL). I added fuel with A0014 to get B2 AFR down to a decent value, but then B1 is rich.

While testing shows more than 1% variation in peak injector flow, it is the erratic behavior at lower duty cycles that is more concerning.

[joecar]

I'm wondering if both banks are lean and somehow bank 1 is getting more fuel (leaky injector)... or maybe oil (rings, guides, PCV)...

hmmm, how does oil effect exhaust lambda...?

[DrX]

Tore it down this weekend to check it out. http://ls1tech.com/forums/generation...000-miles.html

[joecar]

Some scuffing on cylinders/pistons, and deposits in exhuaust ports (I'm viewing the pix on my small phone)...?