Keith91sub

I am making progress with my tuning and my WideBand readings are getting closer to the 14:1 range. I have been struggling with a situation where my WB was contradicting my BLM readings.
In an attempt to double check my NBO2 I am now using the simulated NB from my Innovate LC1 to feed the ECM. I was surprised to see that the WB gauge was still reading around the 12:1 – 13:1 AFR while my BLMs and Integrator were pretty close to 128. I thought that if my NB was bad that could explain the rich readings while my ecm was not reading rich – not the case however as my simulated NB gave similar readings.

Now here is my hope for an explanation: Under a normal and well tuned engine (consider a stock motor/tune) should the WBO2 read 14:1AFR under normal driving conditions? Now people state that higher BLM readings indicate a lean motor. Would the WBO2 read lean with say a 150BLM and stable Integrator or should it still read 14.7:1? My thinking is that the BLMs should self regulate the AFR to try to maintain a 14.7:1 AFR. So is the VE table just the starting point for the fueling and the BLM then adds to or subtracts from the Injector Pulse Width to maintain the 14.7AFR? If this is correct, how could my AFR not be 14.7:1? Does changing the VE tables (within reason) change the AFR or just keep the BLMs closer to 128?

One situation that I can not get my head around is under a few conditions ie: MAP reading in 60s and RPMs = 2500 my integrator and BLMs shoot up with BLM=170ish and at the same time I watch my WBO2 drop from 13:1 range to a reading in the 10:1 range. It is just odd that the BLMs shoot up to richen the motor for some reason. It does work to richen the motor to the point of being in the low 10:1 range.

I have also been only getting about 8 mpg, so I am pretty sure that the WBO2 numbers are correct.

Sorry to ramble, but I feel like I am chasing my tail. I have made a bit of progress getting readings closer to the 14:1 range but I still get weird results as I described. I am pretty sure that I am not in any WOT or PE mode also.

Thanks,

RBob

iTrader: (1)

Sounds like the either the ECM, the NB O2 wiring, or the calibration is bad.

Grab a data log of the steady state cruising and graph the NB O2 signal (can include RPM, MAP, and MPH). During this time it should look like a sine wave going from about 100 mV to 800-900 mV and back.

RBob.

Ronny

iTrader: (1)

My WB is not calibrated for E10. My WB running E10 shows 14.7 in CL which is stoich for REG gas. E10 is 14.3/1. Since my WB is not calibrated, 14.7 reading on gauge in CL is stoich for E10. If I switch to lambda it will read 1.0 for E10.

My understanding.

I dont believe a high BLM is lean as long as it is within the range of BLM that A/F can be corrected. My limit I recall is 160 in .bin? So a 150 should be corrected to stoich.

Keith91sub

I thought it may be a bad NB until I replaced it with my LC1 Simulated NB and have the same results. The NB switched fast, but jumps from low 400 range to 700's (normal?). I also replaced the ECM to solve a tranny problem but no changes to tunning. The odd thing is that the BLM's seem to work to richen the motor when it would be already reading rich.
When you say the calibration is bad what are you refering to?

I am running a pretty conservative tune right now. It is basically the stock tune with changes only to the VE, Spark timing, BPW constant, and tranny settings (I am sure I am forgetting a few things here).

One example that I would like to present: When I turn my A/C on the WB reads very rich. At idel it drops to the 10:1 - mid 9:1 AFR range. While cruising it will drop to the 10:1 - low 11:1 range. Again the BLM's shoot up when this happens.

Could the EGR cause any of these symptoms?
Thanks again for the help.

Drumer919

Whats your target AFR set at? Are you talking about cruise or WOT/on power tuning here?

What is your INT?

Keith91sub

I am running an 16147060 PCM with the $85 mask.
I can not find a target AFR setting but it would not have been changed from stock.
My readings are at steady cruise well bellow the WOT threshold.
Integrator stabilizes at 128. At times it will shoot up and BLMs quickly climb until Integrator stabilizes back at 128.

RBob

iTrader: (1)

The target AFR doesn't matter in closed loop. The ECM changes the INT with regards to the NB O2 sensor reading compared to a series of calibration tables (in milli-volts). The BLM then follows the INT. If the INT is above 128 + an offset, then the BLM increases. Ditto for INT less then 128.

The NB switched fast, but jumps from low 400 range to 700's (normal?).

I would say no, not correct. Not enough swing. Does it also sit low for a longer period of time then high? That will make the INT increase. There may be grounding issues between the ECM and the engine block.

Here is a graph of the NB O2 stabilizing into cruise after an acceleration.

RBob.

Keith91sub

I drove on the freeway a bit during lunch today and will share my observations:
- For the most part the WB readings were around 13.5:1 - 14:1 AFR w/ BLMs steady around 128
- Occasionally AFR would drop to 12:1 range
- When I ran my A/C WB would read low 10:1 range, NB would drop as well and look to range between 100's and 400's. Integrator jumps up and BLMs peg at max of 172. Remember, my NB signal is comming from (simulated from) my LC-1 WB. How is it that my WB would read low 10:1 range while it simulates a NB well below the .450mv? It should be the oposite, right?

I am running a Holley TBI unit. Could that cause anything like this?

Ronny

iTrader: (1)

Are you getting a CE blink then steady on when you turn ign on?

I think RBob gave you something here to check: Sounds like the either the ECM, the NB O2 wiring, or the calibration is bad.

ECM ground?

Keith91sub

What is the CE? If check engine or SES then it is not on when engine is running.

I have the same results from 2 separate ECMs
I will check NB wiring and ground, but I am using simulated NB from my WBO2. I would think the numbers should tie.

I will defenatly check the ECM ground.
What calibration are you refering to?

thanks,

Ericc

Hi Keith,

I found your posts very interesting. I've been working on a tune for my 90' Sub using Rbob's great EBL Flash and I've had almost the exact same problems your listing. Ironically I'm also using the Holley TBI but as an air valve only. I'm running a port injected setup.

I have completely abandoned my LC-1 as being a useful tool on my Suburban. Regardless of how clean the voltage, great the grounding, at times my WBO2 would simply return me values that made no sense. Most of the time it's values seem "about right" then it leaves the realm of the sane. Every day my Wide band learns would completely change my VE tables. 10-12% changes all over the place. After a few thousand learns I cut my losses.

My NBO2 is what I'm closing the loop on so NBO2 Learns is what I went back to.. Suddenly the VE table stopped looking like a crater field and my daily changes where 0-1%. I cant say for sure what the WB's problem is. I've removed it and calibrated it weekly. My gut thinks that the E10 here in CA. might be doing something. The only time the WB seem's about right is in highway mode when Im up around 16-17AFR.

The A/C example you gave is one I see all the time. With my A/C on my WBO2 drops and tells me I'm 10-12AFR with my NBO2 bouncing around 500mv with the INT not moving. I thought that the AC Clutch was messing with the LC-1 so I wired a separate battery to JUST power the AC clutch and the same damn thing happens.

I saw rbob's graph of the NB swing. I never see the NB swing that much (This is likely me messing with EBL.) I usually see +/- 200mv swing around whatever I set the tune too.

Gas milage is around 14mpg (60% city/40% Highway). In hiway mode at 70mph the EBL Flash / WUD display says Im running 20-21mpg. Plugs are very clean. I need to spend some time with the timing but I'm happy with the tune right now.

I wish I had a clue as to why the LC1 on the Suburban sucks. I've replaced almost the entire wiring harness, every sensor, Charcoal canister, EGR valve, every connector, New ground straps, ground wires, Power filters, added a IAT, Fuel pressure transducer, Digital Ignition/coil, etc ad-noseum.

If you figure it out please let me know.. I'm not sure how helpful that was.

Eric

Ronny

iTrader: (1)

CE check engine light. It MUST do the blink before it is solid on engine off. Before you crank.

The Ground for the WB is critical as well as the ECM. If there is a ground differential it may affect the readings. There is info on that issue on Innovate site.

I wont comment on the calibration. Maybe RBob is refering to the xdf file. not sure. Or maybe the .bin? It is said to use a known stock .bin to start with.

My Innovate WB appeaars to work just fine. I have never used it to simulate a NB. Again on the Innovate site and forum is info for initial setup and also forum gets into more details on snags. I run a GM Delco heated NB02. My WB confirms stoich and my VE learns lately move the VE tables 1-3 % as typical(environmental temps swing) and maybe 5% in cells I seldom frequent. This AM I forced high RPM and found 116 BLM in a cell or two so I will see what it pulled in Learn. I think my higher RPMs are fat on VE and that is why WOT I see 12.0 commanded to 12.5.

Keith91sub

Interesting observations:
Today I replaced the Holley TBI unit with a bored out stock Rochester unit w/ stock injectors. It made a good difference. I would say that it is running fairly normal for the most part.
When I run the A/C it is still intermittently showing as described above but I did notice something that may be at cause. With the engine at idle and WB showing 10:1ish I was looking at the motor. I saw that the EGR solenoid was vibrating significantly to where the hose to the EGR valve was shaking. I shut the A/C off and the shaking stopped and WB went back to 14:1ish. I turned the A/C back on and WB stayed in the 14:1 range w/ no EGR solenoid shaking this time. Could the EGR solenoid vibration (very significant shaking) cause a vacuumed leak/activation of the EGR valve? Would this cause a false lean - BLM rise - rich condition?

RBob

iTrader: (1)

If the EGR valve starts to leak that usually drives the BLMs down. As the exhaust gases dilute the incoming air.

If the solenoid acts like a vacuum leak, on a mass air system, that can drive the BLMs up as it is unmetered air. Usually doesn't affect a speed density system except for a high idle.

But at the same time stranger things have happened. Easy enough to test, block the vac line to the EGR solenoid and put a block off plate in place of the EGR valve. Then set the EGR enable CTS to max.

RBob.

Ericc

Keith check for exhaust leaks. I found two that where out of sight and suddenly my NB02 looks more like the graph RBob posted above. I still have one to fix but it made a difference.

Eric