91chevz71

Can you guys look at this picture of my datalog at WOT? Injectors are only at 55-59 percent, etc I know there are probably many things wrong here...I just don't know where to start. The O2 looks really rich, plus it only got up to 3900 rpm. goodness gracious
Thanks
1stWOT.JPG
Mike

91chevz71

Got it up to 4400 this time
2ndWOT.JPG

91chevz71

BLM at the time of entry was below 128, so the computer doesn't add any more fuel, correct? Wonder where I got the extra 500 rpm

RednGold86Z

iTrader: (1)

What's your altitude???

91chevz71

Ah, yes. Pressure altitude- 5400 feet MSL. With key on, engine off, MAP is 83.
Colorado

dimented24x7

iTrader: (2)

Also, I dont know how good an indicator of fueling that last cell is. The computer may not immediatly enter PE under transient throttle, so it may make a correction at lower speeds, but then that corretion could cause the engine to go needlessly rich through PE since your stuck in that last cell the whole time.

91chevz71

Ok. So your're saying it's best to enter PE right around 128. In the first run BLM's were like one-thirty something, needing more fuel for PE and causing a more rich O2. In the second, BLM was <128 and the O2 was more lean.
What else can I do get get it to 5K?

dimented24x7

iTrader: (2)

DISREGARD...

91chevz71

I am totally unfamiliar with hex- I should get more familiar. (one of the reasons I bought the EBL)
Maybe that's all she's got...after all it weighs about 7200 pounds with me in it.

dimented24x7

iTrader: (2)

Overall it sounds like the engine needs plain old tuning. Id get a wideband first and see where you are AFR wise. The stock o2 is worthless for WOT tuning. From the readings, the only thing you can deduce is that its richer then stoich for the blend fuel in use.

91chevz71

I really need one of those. What about disabling PE and taking it up into the higer rpms? and seeing what the BLM says?

dimented24x7

iTrader: (2)

OOPS. Crap, lol. I thought you had the PCM from the datalog. It looks really close to the 8192 baud screenshots. Maybe RBob can chime in and say how the BLMs are applied in PE.
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With the wideband, you want to disable closed loop altogether and tune based off of the AFRs. You still want PE to be enabled.

91chevz71

Gotcha. Wouldn't tuning with a wideband open loop then going back to a NB O2 in closed make some differences in terms of BLM in closed loop? I agree that the wideband would be much more accurate, but once I nail all of the VE with the wideband, won't the NB see something else in closed?

dimented24x7

iTrader: (2)

No... As long as you tune to make your desired and actual AFRs match eachother, the narrowband will see the same thing when you restore closed loop, and youll get BLMs around 128 when done if all went well.

91chevz71

Target AFR is 14.7 right now in closed loop. Yeah, it needs WB tuning for sure. Looks like that's my next step. Everything else is ok- electrical, fuel, tranny, etc.
I'm thinking Zeitronix- looks the easiest

RBob

iTrader: (1)

When in WOT, how does the engine run? Rough, low on power, lots of noise and no-go, goes and then looses power? I noticed that the SA is 37 deg in PE mode. Even though it is at 80 KPa MAP, that may be too much timing. A 7200 # vehicle (2 'n a quarter 3rd gens) is not going to be able to run a lot of timing.

The sig shows a 350 HO motor. Is this a vortec headed engine? A brief rundown of the combo will help out on suggestions.

The BLM in PE mode is used if greater then 128, ignored if less then 128. Safety reasons. If you run open loop and do VE Learns with a WB, upon returning to closed loop the BLMs will not be 128. Even though we specify 14.7 AFR as the commanded AFR, the O2 window is really what defines the end AFR. Which in most cases is richer then 14.7:1 AFR.

RBob.

dimented24x7

iTrader: (2)

FWIW, with my vortec, I dont need much more then 30 degrees total at WOT. Any more and it runs rough.

RBob, are BLM updated allowed in PE, like some form of quasi-closed loop?

RBob

iTrader: (1)

Learn is off while in PE mode.

RBob.

dimented24x7

iTrader: (2)

As far as the BLMs go, itll be within 5% of 128 when done unless the rich/lean thresholds and deadband thresholds are way out. I have mine set to run slightly richer at idle for a BLM of 125 and have it set to run slightly lean in cruise for economy, which results in a BLM of 128-130 when all is said and done. It shouldnt be too far out when tuning is complete. Id expect to see the BLMs be confined to 122-134 without alot of change over the short term. If they, the INT, or the AFRs vary alot over a short period of time, then the VE may need some work or it may need to be smoothed out. Having rapidly varying fueling will cause the engine to not run smoothly as the power output will fluctuate, especially around stoich.

dimented24x7

iTrader: (2)

So the BLMs are locked? Definatly good to have it available for the initial tune and run as it could help prevent a lean condition.

I dont know how your BLM routine is set up, but is there an option to disallow fuel corrections in PE? I know that everyone has different wants and tasts, but I never really liked being stuck in the last BLM cell the whole way up as it could skew the fueling.

JMO, but I think its better for him to have it enabled now as its less likely to wash the rings down then break something from being lean/detionation, but once its tuned, might as well disable it as there arent individual BLM cells for PE operation and no CL to update them. Again, JMO...

91chevz71

Ok. I'll pull some timing and wait for my wideband before I get into the WOT areas. Yeah, Rbob you hit it on the head. lots of noise, not enough go.
I'm going to mess with the timing. I knew it was too much.

Thanks!!!
(keep it comin...lol)

MIke

91chevz71

runs smoother with less timing. I did a huge VE learn this morning, about an hour total driving time. didn't change too much, but it is better now. Waitin' on the wideband. I pulled 7 deg from the table, and it defnintely made less power. With my uber high timing, I had 1 or two counts at 3000 rpm and that's it. So, After pulling the 7 deg I added 2 back and it runs more like it should, and maybe a little smoother.
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My setup-
vortec heads
212/222 @ .050, .435i .460e
9.1 to 1 comp
50mm TBI, 2x90inj @ 14psi.
700r4

91chevz71

Just double checked my base timing- it was actually 13 when the EBL thought it was 10. Dist bolt was ok, I think I just read my balancer tab wrong. 'Measure twice, cut once' theory applied here.
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THat VE Learn from today really cleaned things up- can't wait til the ol' Zeitronix hits the mailbox...plus today was the last day of the semester so I'm getting drunk tonight

91chevz71

Thanks Rbob, Dim, and FAST305-
I have changed my timing (reduced by mucho amounts) and it will go to 5k...maybe more.
Mike