ltft logging problem

[zayne0]

What's up my name is Zane, my car is a 92 camaro with an 02 5.3 tahoe engine, engine has had an ls6 intake swap. I have only been using efi live for about a week, I started tuning on the engine, adjusting the timing, pe tables, and trans just a lil bit. But I never realized my ltft weren't registering anything. I am assuming it is doing this because its going closed loop?

[ScarabEpic22]

Depends on a few things, how stock is the tune to begin with? Do you get any data when you log the O2 sensors in the Scan Tool?

[zayne0]

I don't know how "stock" the tune is because I sent the pcm to be flashed for the ls6 intake and injectors so I dont know what all the guy changed, the o2's bounce around between 434 to 456 of ol fault value.

[WeathermanShawn]

Post up a log. Include LONGFT1 and LONGFT2, HO2S11 and HO2S21.

From your brief description it sounds like your O2's may not be operating properly or need replacing. You need to enter closed-loop for Trims to function.

But, only a log will verify.

[Chuck L.]

'the o2's bounce around between 434 to 456 of ol fault value.".

Exactly what my pass O2 read when it died. [New Bosch 15282]

[zayne0]

Alright, I'll try and get a log up, I'm still learning how to use the software. the o2's are only 600-750 miles old. I installed new ones at the time of the engine swap.

[Chuck L.]

Alright, I'll try and get a log up, I'm still learning how to use the software. the o2's are only 600-750 miles old. I installed new ones at the time of the engine swap.

The failure on mine was at about 150 miles after the swap..

[zayne0]

hopefully this works ive never done this before, tell me if i posted it wrong.

[WeathermanShawn]

Well this is an easy one..

I would check the wiring or PCM connections of your O2's. I don't think your getting a signal. At this point it is a mechanical issue and not Tuning.

When you get that issue worked out, then the PCM will compute Trims.

Good luck..

[joecar]

+1 looks like you have open circuit on the NBO2 signal and/or return wires.

[zayne0]

oh boy.... i just loomed the harness :/

[zayne0]

Could you include some side affects of the engine not going closed loop?

[WeathermanShawn]

Could you include some side affects of the engine not going closed loop?

If memory serves me right, you default to open-loop. Your Airflow/fueling would be determined by B0101 and your AFR/EQ by B3605.

Unfortunately that usually leaves fueling very erratic unless each Table is precisely tuned. 99% of people would run rich with the stock values found in B3605. So the car would feel 'boggy'.

I assume its a relatively 'easy' mechanical fix?

[Taz]

The 5.3 L is a 2002 model - are the engine wiring harness, PCM (and tune), and front O2 sensors all 2002 truck equipment ? Is the engine harness from a 6.0 L ?


Regards,
Taz

[zayne0]

Taz- no sir, the engine, harness, and pcm are all from the same vehicle. But i had originally sent the harness off to get it reworked for my camaro... twice... so finally i just did what i shouldve done in the first place and worked the harness myself. Obviuosly i have made a mistake with the wiring on the o2's. the tune is not factory. i cannot say what all has been adjusted because i didnt do the flash for the ls6 intake and injectors. and yes the front o2's correct. the vin# actually come up saying the engine originated from canada and those models take a diff o2 sensor found that out the hard way...
Weatherman- Chasing wires is a hit n miss sometimes its, easy sometimes... well it can a lot of time

[Taz]

OK ... that sounds good ... in 2002 4.8 L and 5.3 L engines used Case Grounded O2 sensors. The 6.0 L used Isolated Grounded front O2 sensors and either type on the rear O2 sensors.

I would recommend you clean / check the ground wires from the harness. After that, a digital volt meter with an audible continuity function is the fastest way to confirm the integrity of the wiring to the O2 sensors. Also, double check the respective pinout locations.

Also, if you did the harness work yourself check the power supply (and fuse) to the O2 sensors - OEM circuit is 15 amps.


Regards,
Taz

[zayne0]

ya im really not looking forward to this...