Truck falls flat after 3000 rpm.

[mmigacz]

Actually if you set the Stoich to 14.13 it will even change the closed loop air/fuel ratio value to deliver MORE fuel via longer pulsewidth. Your BLMs will drop some if you already have them close to 128, you will see them shift lower overall. The shift will not be drastic, but it will definitely shift lower. If you want you can scale your VE table by multiply the whole table by 0.96. The difference between 14.7 and 14.13 is right at 4%. Pull 4% out of your VE table and you will be golden. Your open loop air/fuel ratio will be richer. Your PE air/fuel ratio will not be.

Just when you think you have things figured out this happens......Here is an example: VE tables are tuned with the same gas (no ethanol) and all BLMs are perfect (128) while in closed loop.... The scaler stoich AFR was set a 14.7 during the tuning process.... Wideband gauge is reading 14.7 AFR (1 lambda)....Now, I change the stoich AFR scaler to 13 and make a run with the same gas. You're saying the ecm is going to trim my fuel to run richer in closed loop (approximately 13 at the wideband)? In other words the BLM will increase (go above 128) to make the mixture richer than 14.7?

[Fast355]

Just when you think you have things figured out this happens......Here is an example: VE tables are tuned with the same gas (no ethanol) and all BLMs are perfect (128) while in closed loop.... The scaler stoich AFR was set a 14.7 during the tuning process.... Wideband gauge is reading 14.7 AFR (1 lambda)....Now, I change the stoich AFR scaler to 13 and make a run with the same gas. You're saying the ecm is going to trim my fuel to run richer in closed loop (approximately 13 at the wideband)? In other words the BLM will increase (go above 128) to make the mixture richer than 14.7?

Here is what happens. The Command Air/Fuel ratio is used directly in the equation the ECM uses to calculate pulsewidth. If you decrease the value, commanding richer the ecm will lengthen the pulse width. This will cause the engine to run richer. Since the 02 sensor is not an air/fuel ratio sensor rather a Lambda sensor it will continue switching around the stoichiometric value of the fuel. I am going to use a made up example to further explain. Lets say you have an engine that runs perfectly at 14.7:1 on a regular gasoline that is 14.7:1. Now you switch to a fuel with a stoich value of 20:1. No changes are made to the ECM or injectors. Your BLM value will drop to a lower value. Now lets say we change to a fuel with a 10:1 stoich. With no changes the BLMs will rise through the roof. Now if you change the stoich scaler to match the fuel in use the same tune can still be utilized with some other tweaks. Crank, AE/DE and PE to name a few. Years ago I played with running a TPI engine on E85 and the tune only required minor changes. With the 7730 ECM I was running ALL fuel calculations were modified from the stoich value. I changed the stoich value. I then increased the AE by the percentage of change of the stoich value and decreased the DE by the same. The result was a tune that was very close.If we run the same fuel and switch the stoich value to 10:1, the 02 sensor will still switch at the same 14.7:1 but the ECM will be commanding a longer pulsewidth, the BLMs will drop way below 128. Now if you change the stoich value to 20:1 the ECM will make the pulsewidth shorter and the BLMs will rise far above 128.I hope my explination makes sense.In your scenario changing the stoich value would initially give you a richer mixture, but the 02 sensor would quickly start trimming the fuel back and if the BLMs could provide sufficient trimming, you will end up back at 14.7:1 with BLM values lower than 100. If you are having any doubt set it at say 13.5:1 and let it run and watch what happens.

[joegreen]

Before i was taking pictures of the text box before it disappeared. Now i can just read it with the edit xdf option. Thanks. I have a couple question. Do i only need to change the stoich afr to 14.13 or do i need to change other parameters........................................ .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. .."Stoich of Fuel used, Gasoline is 14.7 and E10 fuel is closer to 14.13 The value labeled 'stoich' needs to match the O2 sensor AFR switch point. This stoich value, plus the R/L O2 error boundaries, define the O2 sensor output levels. This ties the O2 sensor calibration into the PW equation.As the R/L O2 Error Boundaries define actual O2 sensor stoich switch point in output volts. The 14.7 AFR switch point of the O2 sensor is now 'calibrated' into the PW calculation.If a different fuel is used, with say a stoich value of 16.1, by placing the value of 161 at 0x2AA, the PW is again calibrated for that fuel. If you now want to command the ECM to change the PW enough for a 15.3 AFR, by using 153 in the PW calculation, the PW will be increased the proper amount to produce that AFR (in open loop)............................................. .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. ............................................"What does this mean "If a different fuel is used, with say a stoich value of 16.1, by placing the value of 161 at 0x2AA"?where is 0x2AA?............................................ .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. .................................................. ............................................My other question is when adding AE should i just add tps ae or should i also add map ae. Right now i doubled my map and tps ae from stock. When tuning the ae how do i know if i should add tps ae or map ae? Thanks for all your help. trucks running better already. PS. sorry about all the periods. Cant figure out how to space lines.

[Fast355]

Before i was taking pictures of the text box before it disappeared. Now i can just read it with the edit xdf option. Thanks. I have a couple question. Do i only need to change the stoich afr to 14.13 or do i need to change other parameters. "Stoich of Fuel used, Gasoline is 14.7 and E10 fuel is closer to 14.13 The value labeled 'stoich' needs to match the O2 sensor AFR switch point. This stoich value, plus the R/L O2 error boundaries, define the O2 sensor output levels. This ties the O2 sensor calibration into the PW equation.As the R/L O2 Error Boundaries define actual O2 sensor stoich switch point in output volts. The 14.7 AFR switch point of the O2 sensor is now 'calibrated' into the PW calculation.If a different fuel is used, with say a stoich value of 16.1, by placing the value of 161 at 0x2AA, the PW is again calibrated for that fuel. If you now want to command the ECM to change the PW enough for a 15.3 AFR, by using 153 in the PW calculation, the PW will be increased the proper amount to produce that AFR (in open loop)."What does this mean "If a different fuel is used, with say a stoich value of 16.1, by placing the value of 161 at 0x2AA"? where is 0x2AA?My other question is when adding AE should i just add tps ae or should i also add map ae. Right now i doubled my map and tps ae from stock. When tuning the ae how do i know if i should add tps ae or map ae? Thanks for all your help. trucks running better already.

TPS AE is used when the throttle plate moves. MAP AE is used furing manifold pressure changes. TPS AE is a short burst of fuel where MAP AE is more sustained. Generally you want to balance them both out. You can tell when you have too much or too little MAP AE when the transmission upshifts at part throttle with no throttle input changes. If you get a lean or rich spike on a part throttle upshift you need to adjust the MAP AE. Generally speaking TPS AE is like the pump cam on a Holley carb and the MAP AE is like changing the squirter. The decay rate is like changing the accelerator pump capacity. Longer decay = longer duration of AE.

[mmigacz]

Thanks Fast355! I understand how it works now.

"?where is0x2AA? .

See the attached picture. You can change the bin thru the hex editor or the thru the parameters defined in the XDF. Stoich AFR is already defined in the XDF, so just put in the AFR of the fuel you are using. In this case 14.13.

Cant figure out how to space lines.

Me either.

[joegreen]

Thanks. That picture helped alot. Did couple more ve learns with afr at 14.13. The truck is driving better ind im betting the blm's closer to 128. Right now they are around 123-130 except at idle where its still at 118 even after adjusting the ve. I have closed loop idle set so i should be getting good idle blm data.------------------------------------------------------------------------------------------------------------------------------------------------------Second thing, if i give it gas from dead stop it bogs and then picks up, this is after i doubled the tps and map ae. I know this means i should add tps AE. Should i just increase the tps ae until that goes away and not touch the map ae? Also should i double the tps ae again? I dont want to over do adding tpa ae but i also dont want to keep adding barely any ae. ---------------------------------------------------------------------------------------------Now lets say im holding down the brake and pushing on the gas. The truck wont make much power at first then after say 5-10 seconds it will start to move overcoming the brake friction. Why does it take time to make power? What parameters should i be looking at?---------------------------------------Lastly i have my cts in the intake manifold. Sometimes at idle it reads 185f. At what temperature does the ecm think the engine is fully warmed up. I dont want to be adjusting idle ve when the ecm thinks the engine is not fully warmed up.

[mmigacz]

Record a log of it accelerating from a dead stop and post it.... Also, post an updated bin.....Did you modify your timing table? The bin that you posted has an crappy timing table. Try the timing table in the bin I posted. See if it peps up.

[joegreen]

I havent changed any timing yet. Im pretty new to this tuning and the walk through said to adjust ve first. Do you want a log after i add the timing table or before. Here is a log from my 20 mile ride home. The bin posted is after i changed the ve table from my drive home today.