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trying to get my swap running. its DBW, first startup attempts since building it and putting it into an old C10. using HP tuners
mods are lq4 block with stock pistons
243 heads
stock intake mani and TB (DBW, pedal, tac module, TB, PCM all match from same vehicle)
headers
TSP 228r cam
BTR .660 springs
7.375 pushrods
ls7 lifters
New primary O2's (rear o2, and all other emissions turned off)
harness is a modified stock harness to run standalone.
Click image for larger version.
heres my LTFTs, at idle. AFR goes super lean and is intalled on the passenger side a few inches behind the O2.
Driver side pulled a plug, its sooty black, rich.
passenger side pulled a plug, white tip, lean.
Clear your fuel trims. Looks like your not in closed loop as the STFT's are 0. Delete the start up coolant temp & add engine temp. Also add the commanded AFR pid, so the AFR Error histogram will work.
Any O2 sensor codes? As they will prevent closed loop fueling.
I just bought HP tuners due to a lack of tuning support in my area.
can you briefly go over how to
-clear fuel trims
-add engine temp (I'm assuming removing startup temp is just right click and remove)
-add commanded AFR pid
also, no 02 codes, i checked codes today before i took that screenshot.
In the scanner you will see a button that allows you to "clear trims".
Delete it like you said. Then add field. Should be listed under engine called ECT(engine coolant temp).
Same thing, when you add a PID by clicking on an empty cell there is a list of things to add. Commanded AFR is one of them.
It's possible the o2's are swapped but more likely a bad sensor. A clogged fuel injector on one bank can do it as well.
Add bank 2 inj pw as well. Idle should be roughly around 2-3ms depending on how big they(injectors) are. Driver side is black because that pw is too high. I bet the pass side pw is at min low.
In editor on the trims tab under engine/fuel there is a box to turn STFT on/off. Turn them on.
additionally, both your 02 sensors are showing 447 mV which is a dead sensor reading if they don't move more than 5 or 10 mV from this value. often with swaps, this is in the wiring for the 02 sensors.
Dave
additionally, both your 02 sensors are showing 447 mV which is a dead sensor reading if they don't move more than 5 or 10 mV from this value. often with swaps, this is in the wiring for the 02 sensors.
Dave
thats what caught my attention as well.
for reference, the o2's operate from 0-1v the higher the measurement the richer the reading. Scan tools display this output in milivolts .447 (milivolts) is middle of the road as the number goes up say .850 would be rich and .250 would be lean. Once the system enters closed loop you should see these values switch back and forth between rich and lean and the ECM tries to maintain the commanded AFR. So if they are setting still that usually indicates bad sensor or connection.
since this is in a swap, are you sure the front o2's are connected to the front o2 connecors for the harness?
When you deleted the rear o2's are you sure you didnt turn off the fronts as well?
Ive recently been going through a similar issues but mine ended up being an ECM issue. the passenger o2 is reading .250 and the ecm interprets a lean condition and keeps overfueling bank 2 to try and richen up the perceived AFR and when it doesnt see that it just keeps adding. My scan log shows the bank 2 injector pulse to be double bank 1 or higher at times.
clared fuel trims, and now it wont even start. huh.'
but tried to do the other things people are suggesting as well, cant get engine temp in the PIDs, anyone know why this is? also, for injector bank 2 PW i cant add that either, its not an option?
And the wiring harness was reworked to be a standalone, so its very possible the guy who did it did so improperly.
Heres a log from yesterday when the motor would run. if you will take note of the o2 Mv, they both go full opposite. i dont know how to upload the log, but in watching it, when i started the truck they were both around 447, then they both diverge. and from my AFR guage, the bank that the widebaad o2 is in went more and more lean, which is in line with the log.
is that indicative of o2 wiring being flipped for the banks?
The first image you posted isn't but the last one you posted is.
the image i posted today at 630ish was from a running log yesterday. See below for that short log file. its the second (lower) attatchment. My worry is that the guy who did this harness messed it up.
Also, just flashed the stock tune back on it (modified injector tables so it would run potentially), and turned off closed loop and turned off fuel trim learn, and the AFR hung around 12.3-14.5. much better than the 17+ i was getting before. that again points to an issue with either;
1. and o2 sensor
2. my o2 wiring is into the wrong pin in the ECM connector
whats all your thoughts? also thanks for the help so far.
below is the log with the closed loop off and fuel trim learn off from just now
I would disconnect one of the o2's so and check the scanner to see which goes dead and if they dont match you know for sure.
I wondered if they were backwards, but based on just the still of the scan its hard to say since thats just a split second snapshot (didnt watch the log yet). I will say the injector pulse seems rather high to me, but im basing that off of my car that has 60lb injectors. though it would make sense as to why it would be so high if its reading the wrong o2. as well as explain why bank 2 is so lean if its trying to correct the rich reading from bank1 which it cant so it keeps leaning out.
I will test continuity from each o2 and see whether it is reporting to the proper PCM bank pinout, respectively. Ill report back with my findings today after work.
well my o2 wiring was backwards. the o2 in the passenger side was in the PCM location for B1S1, and the 02 in the driver side was in the PCM location for B2S1.
Now i think i just need to adjust tuning for all my modification and it should run.
What a pain. pay for someone to modify the harness and comes back with this issue and also was chasing grounds. Same guy also did my base tune, so im not trusting that either. Guess i will learn some tuning basics and see how it goes.
Thanks for everyone who pointed me in the right direction!
glad you got it figured out, that should make everything else fall into place.
I had the same issues Ive paid 3 different people for tunes one of which was my base tune which I later found out they didnt make any of the specific adjustments I requested like speed density and injector flow rate. I also decided to pick up the software and give it a shot. So im still learning myself, but there is so much you can change with hptuners. I know its expensive but I would look into the tuning school that is offered. Its $400 bucks through Scoggins, but you get a wealth of knowledge that for a beginner is well worth the money. several very detailed books as well as a DVD that goes into depth about the processes and understanding what the scanner is telling you and how to interpret it.
I may look into something like that, i know im missing out on so much of its features by just googling and seeing what forums say on how to do things.
I do want to figure out how to run AFR via wideband vs commanded AFR, get the error histogram, then edit my VE table by that to get things really close. but i just know how it explain it not to do that yet haha
if you got the pro version i would just wire it up into the hptuners adapter and be done with it, I did the wire into the egr wiring method but that kind makes the install a bit more permanent, and since I have other cars It would have been nice to have the option to move it around between cars.
The VCM scanner alone on this thing is worth the money though I think
09-13-2015, 09:47 AM
Bank 1 LTFT 25%, bank 2 LTFT -3.9% 
