Can't get off low octane timing table...

[2slow4u]

I can seem to get off the low octane table. I am seeing a max of 22 deg of timing at WOT. I tried to log the scaler pid and it looks like it isnt coming off the low octane table. Can anyone take a look at my log and tune and see what I am missing? Thanks

98' camaro M6

prc 2.5 (5.3) heads milled to 59cc
ms3 cam
ls6 intake an tb
lid
pacesetter LT w/ off road Y and hooker catback
stock 28lbs injectors

[roy]

I am currently at work so I can't view.
But can ask some questions.
Are you running Mafless?
Did you copy and paste the High octane table into the low octane table?

[2slow4u]

I am still running the MAF and I have not copied my high octane table into my low octane table. I did modify my low octance table , a bit, and make another run and logged it. Looks like I am commanding the right timing, but now I am pulling 3-4 degrees of timing. New tune and log are attached. Thanks for any help!

[roy]

I am not quite sure but it looks like yor still failing your MAF. Your Maf lowspeed freq limits are way different than stock. Also P0102 is set to no mil so if it was failing you wouldn't know.
Are there any set DTC's ?
Oh btw I am not the smartest at deciphering this. Maybe some one else will chime in with knowledge.

[odd boy]

I see your ECU using the high octane table, for example see the below pics:


At RPM = 5229
Commanded spark = 25.6
Retard= 4
ECT correction = 0
IAT spark correction = 0
Running Spark = 25.6 – 4 – 0 – 0 = 21.6 deg

Moreover, it looks your AFR is lean. The car shouldn’t knock at this low IAT temp unless u r using low octane fuel or the compression is higher than stock.

5265
5266

[JezzaB]

First id be having a look to see why your injector duty cycle is lower on one bank than the other and the O2 sensors and the LTFTs are saying the same thing. One of your O2 sensors maybe shagged or something else.

Jez

[2slow4u]

Thanks for the feedback, I am going to get the car on a wide band in a few days. The compression is around 11.5:1. It looks like the octane scaler parameter is disabled (b6220)... any reason why this should have been disabled?

[2slow4u]

Got 2 new 02 sensors and took care of the knock and fuel trims. Thanks guys!!!

[odd boy]

good for u

[2slow4u]

Well spoke a little too soon. The O2 sensors smoothed it out a bit and got rid of the heater codes, but now its back to adding 16-17% fuel on bank 1 and 5-7% on bank 2. I have checked all the coil packs and plugs as well as checked for intake leaks. Can't seem to find anything, but I have a slight exhuast leak by the collector ( crappy clamps from previous owner ) and am wondering if the leak is enough to make the O2 sensor read a bit lean...?

[odd boy]

Well spoke a little too soon. The O2 sensors smoothed it out a bit and got rid of the heater codes, but now its back to adding 16-17% fuel on bank 1 and 5-7% on bank 2. I have checked all the coil packs and plugs as well as checked for intake leaks. Can't seem to find anything, but I have a slight exhuast leak by the collector ( crappy clamps from previous owner ) and am wondering if the leak is enough to make the O2 sensor read a bit lean...?

I don't think. I saw the injectors duty cycle are different, why don't u clean them??

Last thing, force open loop and remove the O2 sensors!!!

[joecar]

Maybe you have an air leak on bank 1.

Also, is it just me, or is your B5910 trying to pull 6° (see image).

[2slow4u]

I think, on that table, it will only pull out 6 deg. if the engine temp is over 240+ deg... I am running around 192 deg. It does look like that table is pulling out quite a bit of timing at a low temp idle/part throttle scenario... Is this pretty common? I am working off a mail order tune that the car came with...

[joecar]

Oh, I just realized I fell into the mismatched units hole (140F was being treated as 140C)... lol...:doh2:...:hihi:

... I fixed my units configuration, and now I agree with you, please disregard my post #12.

:)

[2slow4u]

No problem:) ... I did another log after tweaking a few things and I got my timing back, but still can't figure out this lean issue on bank 1 :mad:

- see attached log...

[joecar]

If you have a leak on the bank 1 collector, that may be sucking in air (each pressure pulse is followed by a "vacuum" pulse).

[The Alchemist]

Even small leaks are enough to throw of the O2's been there done that. Fix the leak then relog fuel trims. If you don't you'll be like my dog chasing its tail :) > getting nowhere fast!