reduced engine power with maf failed trying to sd tune

[cody350]

I have a 2009 Pontiac G8 6.0 with a 7875 turbo I am trying to get this thing tuned. I just switched to the OS 2 bar because I was trying to sd tune on original tune but kept going into reduced engine power on that also. When I switched it to the speed density air mode applied It went into the reduced engine power but did not show it on the instrument panel. The only codes the computer has is the P0103 and a couple for the O2 sensor heater. It usually sets off the reduced engine power when I get into boost. what is putting this into reduced engine its hard to log when you can't get a wot.

G8 step 14 2 bar OS step 9 sd mode man vac boost.hpt

[blindsquirrel]

What injectors? Why's the [ECM] 12308 still unchanged from stock? Think it'll work OK with only half the injector data?

[cody350]

Siemens 80lb injectors I got the flow rates and short pulse #s on a different thread. Know of anymore data for these injectors I see they are quite common but can't find all the info

[cody350]

Found this data on another thread seems to have everythingFord to GM Injector Data Conversion 80lbs Siemens Deka (3).xls. added in the 12308. do see any other important injector data i am missing?G8 2 bar OS step 13 help2.hpt

[SultanHassanMasTuning]

can we see key on engine off log

[cody350]

dont have koeo on this log but it is 99-100 kpa. at around 18:16:12 is where it goes rep rep.hpl

[eXo3901]

If you aren't happy with the spreadsheet data you found for the injectors you can try the changes in this file. This uses the second file you posted.

Post your MAP sensor part number.

So it still goes into REP after you made those changes to the P0068 section? Can you post the DTC's that are coming up when it happens?

[cody350]

19418810 is the gm part # I put in the oem not aftermarket. Yes I will definitely try out your revised Thank you, much appreciated its amazing how helpful people are on this forum. i hope i can gain some more knowledge to help out it in the future. I tried out the last tune I posted today but that one was really rich and wouldn't accelerate made a few to many changes I might have to back track on that one a bit. But I will try out data you sent. I had someone else tell me that data was way off on my last tune also. I was only getting p0103 and p0050 the first times it was going into rep after that i have been messing around with the last tune now I haven't been able to make a good safe wot pull yet.

[eXo3901]

Changing injector data without adjusting the VE/MAF, whatever it's using, will probably run rich/lean. Injector data is static, so if it's wrong to start all your adjustments are baked into your VE/MAF tables. When you change to good data(change to any data really), you need to retune it all. Huge waste of time. Same thing with MAP sensors. So plan to re-tune this thing if you use the changes I posted.

[cody350]

Hasn't been going into rep the last couple logs. I had a few things changed all at once with some help from another member but I believe it was the p0068 section that has allowed me to do a wot pull. I couldn't get it to stay running with either of the injector offset datas that were shared previously couldn't get it to run long enough to get my wb to log tried going rich tried lean couldn't keep it running. I had to go back to the the stock offset though it doesn't idle very well yet. Still pretty rich when I first stomp on it and it is very slow to accelerate till the turbo spools up and then it pulls you into the seat. while cruising you can feel it kind of oscillating or pulsing I don't know if that is because of the not so perfect injector data or if it is just needing more logging and dialing in the VE. IDK first timer here so don't know if I should keep tuning with these injectors or what.G8 turbo ve step 2.hpt

[eXo3901]

You need to use 1 of the 2 sets of injector data in this thread if you are going to stick with the Deka80s. I did not like how the offset vs. volts vs. vacuum table is calculate in the excel file you found. You can tell it was calculated in excel as it fly's off the chart, but the car will never see those areas on the table. That does not mean the data range the car will use is wrong. That is the only reason I provided what I did. But both sets of data are as close as you are going to get to the real thing for generic Deka80s. So pick one, enter the data into your file and tune the car. Injector data is static and does not change unless the physical part changes. So stop changing it after you pick one of the 2 datasets.

You've destroyed your VE tables in your most recent tune file in post #10. Probably best to start fresh with a stock VE table, at-least in the idle area, after you have entered 1 of the 2 sets of correct injector data.

Why is idle RPM set to 900?

This is just a turbo and injectors so I would not expect the VE table to be much different than stock below 2,000'ish rpm. The not idling should be easily sorted with correct injector data and a few quick revisions to the VE table. What else is done to the car? What is fuel pressure at the rail? What type of fuel system is installed? Aftermarket cam? Just doesn't make sense that this wont easily run down low. If truly no other mods, I suspect china injectors.

We needs data logs of the issues you are describing as well.

[cody350]

BTR stage 2 turbo cam, stock fuel delivery with a walbro 450 stuffed in the stock bucket, 58 psi. I will give the other injector data another try. Do you have a good base ve table to start with i have to transform my axis column & rows if i use my stock VE table.

[cody350]

where is the stock ve table for thisG8 1ST READ.hpt

[blindsquirrel]

The stock VVE table, converted to the VE format.

[cody350]

ok yep up in the edit tab not in the engine. now I remember sorry about that

[cody350]

Ok I tried to build a ve table off of what I gathered off of youtube n the forum and switched back to eXo3901's injector data does the ve graph look like it could start or run I have no idea if this right this is my first time.

G8 turbo new stock ve conversion with new inj data.hpt

[eXo3901]

Ok I tried to build a ve table off of what I gathered off of youtube n the forum and switched back to eXo3901's injector data does the ve graph look like it could start or run I have no idea if this right this is my first time.

G8 turbo new stock ve conversion with new inj data.hpt

Take a look at this revision. It uses this file to start and your stock VVE table as a reference for VE. I ran it through excel once to generate the VE from the VVE table. Then popped that into the tune file. Copied the 76kpa column to the 200kpa column and increased it by 10%. Then interpolate from 76kpa to 200kpa. Then I copied that table back into a different excel sheet and smoothed it. The low RPM/kpa area came out 15%'ish lower than the stock VVE table so that should account for the larger cam and its decreased efficiency at low rpm. I would say that is a good starting VE table just to get this thing running. Don't assuming this VE table is good under any type of load except idle, so keep an eye on your wideband before getting into this thing outside of idle. Don't forget to get logs as well. Also take note of the general shape and smoothness of the table, you want to shoot for something like that. No big cliffs or mountains. Any questions on any of the changes just ask.

[cody350]

ran a little log on my lunch break it was running pretty good at first besides really lean if i slowly accelerate hanging in one gear so most of the time i was giving it pretty good throttle then it would stay rich under a load. the idle was again a little all over 600-900 always searching. it was cruising pretty good for the first half then it started to really shutter at low rpm 1600ish if i just barely had some throttle as you can see around 12:58:30 my narrow band was jumping all over the place. Is that bad injectors dumping to much fuel?G8 turbo new stock ve conversion with new inj data - V1 1st log.hplG8 turbo new stock ve conversion with new inj data - V1 1st log.hpl

[eXo3901]

Need to add Dynamic Airflow, Cylinder/Spark Airmass, Volumetric Efficiency(mg*K/kpa), Manifold Air Temp, Intake Valve Temp, injector pulse width, some knock channels, and fuel trim cell to your logged channels. Remove all SAE throttle channels and re-add NON-SAE throttle channels. Try to use as many NON-SAE channels as possible. Remove and replace them where possible. Update polling rates so they are all similar.

How did it start?
Do you have a boost-a-pump installed?
Highlight entire RPM rows/columns from 600 to 2,000. Add 5% (x1.05) to everything highlighted. Then highlight entire RPM rows/columns from 400 to 3,000 and click smooth either horizontal or vertical, whatever the RPM axis is. Click it about 5 times.
Add 5% (x1.05) to your base idle airflow 400-1600 rpm columns.

We need logs of KOEO. Also need logs of operating temp idle and some steady state throttle cruising, both taken NOT directly after a reflash if possible.

[cody350]

Ok sounds good i will add them. i did add injector pulse width b1 b2 and injector duty earlier today but i will add the others but looks like i have some work to do first I brought it in the shop today and found one of my problems. probably the shutter I was feeling at low rpm was the plug wire that melted to the down pipe even thru my dei plug wire cover. need to find a different route and a 90 degree boot for that one.