PE Not Responding????!!

[06x6spdGTO]

Ive been trying to tackle a tune on a 2002 Firehawk with ported 241's and a Cartek 2x Cam w/ LTs and Off road pipe. I thought i had the tune nailed down about 2 months ago but now the car has started to leave a greyish smoke at idle and Idle only. So i figured id take a look at it. I hooked my LM-1 WB up to the car via the rear o2 sensor bung on bank 2. The car was reading between 14.5-15.0 AFR at idle in CL but the LTFT after crusing it around were at about -7.0%. So i disable the VE and forced the car in OL to tune the MAF first. It was about 5% off acording to my LM-1 WB. Next i Failed the MAF and switch to VE which was about 6-8% off in places. I adjusted the VE (no dyno, street tune) and turned the MAF, DFCO, and MAP delta high/low back ON. Uploading the tune. We drove the car around for about 20mins. Still seeing the Greyish smoke at idle, and receiving 14.4-14.8 AFR at idle and 14.5-14.8 AFR for Cruising. LTFT were around -.8 to 1.6 for bank 2 and like 3.9 - 5.5 for Bank 1?!? So i told him to do a WOT pull in 3rd gear. I logged 12.2-12.5 AFR so i figured it was a little rich. I adjusted PE from 1.162 to 1.153 uploaded the tune and made another 3rd gear pull. This time i recorded 12.0-12.2 AFR. So reset Fuel Trims and uploaded 1.140 into the PE EQ ratio and made another pull. This time I got 11.9-12.2 AFR. WTF!!!!! Where do i need to look for a problem?? Does this car a valvetrain issue?? Or is it something in my tune?? After working on this car from 5pm to 1am last night i gave up to research and try to tackle the situation today.

[06x6spdGTO]

yeah i reset the Trims on every log for the MAF/VE tuning via the scanner.

is the OL equation ratio table jacked up?? This car was molested before i got to it.

While i was tuning i followed the Banish DVD setting the temp from 108-248* to 1.00 through out the table for the VE and MAF. Then i put the orignal values back in when i finished.

[mowton]

I eventually read you reset the trims so I deleted my post...sorry.

The Open Loop table is essentially stock where it is rich. I normally leave mine at 1.0 from 140 to 212 then richen it. But if you were in closed loop than it shouldn't matter.

One thing my tuner mentor once told me, when in doubt, go back to stock and start all over.....Sometimes it helps

It looks like the ltft's may be playing with your PE AFR. Try shutting them off and only usinf STFT.

Ed M

[Frost]

I don't see anything mysterious I just looked at the second log. PE comes in just as it should. You have positive long term trims offsetting WOT. It doesn't matter if you reset them, they will learn quickly. You have to get them negative or turn them off. B1 is 2x what B2 is (LTFT locked value) and you can even see it reflected in the NB O2 voltage with B1 being higher.

Disable your LTFTs, flash the car, start the scanner and goto Displays>VCM Controls>Fuel & Spark and click reset fuel trims. I usually click it twice...

Now go check PE. It will be consistent.

[06x6spdGTO]

Thanks Frost.

Im running the car with the LTFT shutoff and its spits out whatever i want it to for PE now. I.E. I enter 1.135 in PE the car gives me 12.9 - 13.0 AFR.

I did find a problem with B1 vs B2 readings tho. It seems the left side o2 sensor wasnt tight!! I crawled under the car to install the wideband back in the right side this morning and i noticed some black residue on the outside of the o2 bung on the left side. This is probly why its a little lean!!!

[mowton]

Glad disabling the LTFT's helped.....was a good idea. I'll have to remember that for the next time, or learn how to write clearer

Ed M

[kevmo777]

Ive been trying to tackle a tune on a 2002 Firehawk with ported 241's and a Cartek 2x Cam w/ LTs and Off road pipe. I thought i had the tune nailed down about 2 months ago but now the car has started to leave a greyish smoke at idle and Idle only. So i figured id take a look at it. I hooked my LM-1 WB up to the car via the rear o2 sensor bung on bank 2. The car was reading between 14.5-15.0 AFR at idle in CL but the LTFT after crusing it around were at about -7.0%. So i disable the VE and forced the car in OL to tune the MAF first. It was about 5% off acording to my LM-1 WB. Next i Failed the MAF and switch to VE which was about 6-8% off in places. I adjusted the VE (no dyno, street tune) and turned the MAF, DFCO, and MAP delta high/low back ON. Uploading the tune. We drove the car around for about 20mins. Still seeing the Greyish smoke at idle, and receiving 14.4-14.8 AFR at idle and 14.5-14.8 AFR for Cruising. LTFT were around -.8 to 1.6 for bank 2 and like 3.9 - 5.5 for Bank 1?!? So i told him to do a WOT pull in 3rd gear. I logged 12.2-12.5 AFR so i figured it was a little rich. I adjusted PE from 1.162 to 1.153 uploaded the tune and made another 3rd gear pull. This time i recorded 12.0-12.2 AFR. So reset Fuel Trims and uploaded 1.140 into the PE EQ ratio and made another pull. This time I got 11.9-12.2 AFR. WTF!!!!! Where do i need to look for a problem?? Does this car a valvetrain issue?? Or is it something in my tune?? After working on this car from 5pm to 1am last night i gave up to research and try to tackle the situation today.

I expierenced the same problem w/ my ls-6 and found that I needed to disable the COT protection while tuning. This fixed my problem.