simple ve LTFTs question

[passingpower]

^^Yeah, do that.
As long as you don't try to tune WOT, and stick to light accel and lower, with the NB and filter your histograms you'll be golden. Leave the NB WOT tuning for the brave/foolish. To learn all you need to know about filtering, use the search function on these forums to find step by steps others have used.

[mayne]

I would filter out any frames that are not 14.7:1 and any frames that are fuel trim cell 1 which is decel.

you mean 14.4 due to ethanol? I've always wondered what the hell that Fuel Trim Cell is for

[mayne]

this is the table I need to change to 14.4? thanks again!

[Perforator]

The fuel trim cells go like this.
0 = idle
3 = heavy throttle
1 = decel
4 = moderate throttle
2 = everything else

I'm not sure about the ethanol.

[passingpower]

Yes, 14.4x:1 for the ethanol.
By changing the Stoich point of your fuel all you're really doing is the same thing a FlexFuel ECU does. The difference is that you can't do it on the fly using a fuel composition sensor. Instead you have to find out what you're burning and flash that setting. If you know you run pure petrol, it's 14.68. If you know you run 10% Gasahol, it's 14.13. The problem is when some of your local stations tank E-0 and some tank E-10. That's when you are forced to compromise and flash 14.4x. The reason it's a compromise, is that you'll always be a little off but, never more than if you're calibrated for one and burn the other, as in the case of a stock tune in an ethanol state. In my local area, I know I can't get straight petrol from a standard pump. So, I calibrated 14.13. Even so, there's no guarantee that the mix is 10% on any given day - there is variability in the blend comming out of the refinery and storage/distribution. That means you can perfectly ignore that second digit to the right of the decimal point. Hence my recommendation to run 14.4x:1. Just get close. You will also need to bump the Power Enrichment Base AFR vs ECT by the same ammount.(A FF tune does this by making it an Equivalence Ratio based on the Stoich AFR which is in turn adjusted by the reading from the Fuel composition sensor.) Example: your Base AFR in the 160 -212 degree range is 12.4 for N/A. (It's still 12.4 for a SC'd engine even though GM Powertrain really should have set it to 11.7) You subtracted 0.3 from 14.7 to get 14.4 in the Stoich AFR so, Take 0.3 from your Base AFR vs ECT table for the heat soaked engine cells. (150-160 and above) BTW, filter based on a commanded AFR of 14.4:1 for your MAF calibration.

[mayne]

yes its N/A
should the maf be tuned in sd mode? no?
thanks again!

[passingpower]

The MAF can't be tuned in SD mode.

[mayne]

when trying to tune the MAF in CL mode via the LTFTs
If I have already reset my Fuel Trims -
do I have to drive the car for around 100 miles before starting a usable log
or can I just start logging immediately and use that to tune with?
thanks alot

[mayne]

also, if i want to filter out the Fuel Trim Cell = 1 (DECEL) would that be something I do Prior to scanning or after I have a scan log?

Maybe I should turn off deceleration enleanment?
thanks

[passingpower]

Allow the Pcm to learn the trims before
scanning to capture them.

[Perforator]

To filter out FTC 1 you need to add a filter to your histograms, something like [PID.6310] < 1 OR [PID.6310] > 1.

[mayne]

To filter out FTC 1 you need to add a filter to your histograms, something like [PID.6310] < 1 OR [PID.6310] > 1.

yea, thats what I figured... but am not sure I am setting it up right
[PID.6310] <> 1 I think would be the C programmers version?
never been a c programmer though

Allow the Pcm to learn the trims before
scanning to capture them.

you shouldnt have deleted all that good info!!
thanks guys

[mayne]

I went driving around after resetting my fuel trims to start fresh.
Only went for a short 20 minute drive and heard some pinging... now I know for sure that is what pinging sounds like! It is a VERY distinct sound to me!
Just by listening to that sound I KNEW that I had no coolant so I parked and got out and theres coolant all over my engine bay. I'm pretty darn sure its the timing cover gasket even though its REALLY hard for someone to tell.

Enclosed is the last part of the scan:
Do I have a dead O2 Bank 2 sensor?
Why is my computer commanding 16.0 AFRs when I just got done flashing it for a 14.4? Is that "commanded lo res" amount not really what my computer is "commanding" but instead that amount means: it is where its currently at in AFR?
thanks!

[mayne]

if my BANK 2 sensor is bad, is that forcing me into OL? could that be why my "Commanded Lo Res" is way lean? thanks

[passingpower]

I dumped all that stuff because it's formatting was screwed up. I typed it then copied and pasted it using a not too smart phone. Anyway here it is for your reference. I'll clean it up when I get on a PC.

Allow the PCM to learn it's trims first. While you could have your laptop connected during this, there's no point in it. Trim data is worthless for tuning during the learning process. BTW, it's not the 100 mile mark that indicates the trims are learned. Depending on how you drive, your trims can learn at 20 miles or 200 miles. You can tell the trims are learned when STFT is generally small values and are often zero. You can speed this process up by using a steady throttle to hold the engine at different RPM and load (cyl air mass) points long enough for the STFTs to be stored as LTFTs. Driving up and down hills in different gears and speeds is a good way to hit different load points. When you do scan your learned values, it takes much less time. The object is to place your engine at the RPM load points so your laptop can sample and record them for tuning.

[passingpower]

First things first. Don't run that engine at anything more than idle!
Fix that coolant leak, ckeck out the wiring from the O2 sensors to the PCM. I don't see any usefull data from either O2 sensor and your trims aren't learning because of it. That could be the cause of your lean condition which is giving you as much as 15 deg of KR. Thats incredible! I don't doubt you can hear that. You have to mechanically and electrically repair that engine befor you can think of tuning. in the mean time, maybe you can post your HPT file. We can look that over and see if there's anything "off" about that.

[mayne]

thanks, I got the timing cover fixed and took it for a 15 minute drive, my SES light came on so I knew something was up. When I finally parked it I realized my cylinder #1 boot was off of the spark plug! I am reinstalling hpT and will go for another drive to get you all another scan.

[mayne]

fixed my timing cover gasket, its not leaking (yet)
ok, 1st drive I didnt realize spark plug boot on cylinder #1 wasnt connected
still seems like I'm lean and that my o2s arent working
but why is my AFR commanded Lo res commanding SO LEAN?
NO KNOCK at all anymore, I hope the gasket holds

i forgot the definition of lo res

[passingpower]

Judging by your second scan you either have bad O2 sensors or bad wiring connected to them. Your bank one is intermittent. I watched it send good data for about 40 seconds. Your bank two signal line is floating high (at least one volt, likely more) that's falsely telling your PCM that bank two is rich. The PCM responds by pulling fuel with a 16:1 commanded AFR. Good news, I watched the commanded AFR go to 14.40:1 for several seconds while your bank one was sending good signal. Sort out the wiring issue on your O2 sensors and you'll be in business. At this point, don't dismiss the possibility that one or both O2 sensors are contaminated and weakened by coolant, that's one of the first things to be aware of whenever there's a leak, just sayin'. When you're certain you have no leaks, coolant, vacuum or otherwise, consider fresh O2 sensors, they're likely old enough to need replacement anyway.

Edit
I'm using the chart to watch those things and I can only see the fuel trims, not the O2 voltages. When I monitor the O2s in the Table display, I see that O2 B2 looks to be shorted hard to ground and O2 B1 seems to be randomly ignored or is an open circuit. Anyway, you've got some electrical troubleshooting to do. Don't give up.

[mayne]

Do you think I should change my Injector Flow Rate vs kpa VAC table to all 22.27 (the same)?