What causes this!?!?

[12sec.5.3]

On the way to the track tonight at wot the WB was reading ~12.4 as usual for the past 3 weeks. I get to the track, make my first run and hear detonation and the WB is reading 13.8..?????

The run down:
I put a 6.0L in my truck with cam, heads, headers, yada, yada. I had a someone e-mail me a "base" file to put in for the 6.0. Ever since then I've had this problem. I downloaded a stock file for the 6.0 and copied it's ve table over to my current tune. So I have a mild engine with basicly a stock ve table, 31 lbs injectors, and PE set down to 11.0 AFR and still running dangerously lean. What the hell? Anything particular thing I should check in my file?

[Tordne]

What AFR is actually being commanded in the WOT area, and is it being derived from the PE tables or from B3647 in a Custom OS? It could be possible that you are not hitting the PE enables (I've seen a stock truck tune with the PE delay set to 60 seconds :eek:) In this case it you are Open Loop your commanded AFR will be coming from B3605 or B3647 (Custom OS).

Hope that starts to help?

Cheers,

[12sec.5.3]

Only thing I could really find was (B3610) "PE delay RPM bypass" set to 0.

[Tordne]

Check B3608 and B3613 as well as the B3615 & B3616 tables.

[12sec.5.3]

3608 set to 0
3613 set to 55
3615 set to 90 and 85
3616 set from 60 up to 95 and back down to 70

[Tordne]

Hmm... Seems fine and "should invoke" above 60% TP.

If you have the log did you log the commanded AFR? That could help work out which fuel table is being referenced.

[12sec.5.3]

No I didn't log the Commanded AFR, but I will add it to my log file. Wondering if I tuned incorrectly for the bigger injectors.... What is the proper way to do that?

[TAQuickness]

http://www.ls1tech.com/forums/showthread.php?t=287094
http://www.allmod.net/hpt/injectors.xls

[12sec.5.3]

Thanks guys. I know these are some dumb questions but like your sig says, "You don't know what you don't know".

[joecar]

"...you know how when you already know how..." :cheers:

[98SS2836]

Sounds like injectors are not tuned right.

[Tordne]

"...you know how when you already know how..." :cheers:

You are what you eat.. Couldn't think of anything else :muahaha:

[joecar]

"...You think you know you knew you didn't think you knew you didn't..."

[12sec.5.3]

"...You think you know you knew you didn't think you knew you didn't..."
:eek: wow! My head hurts.....

[TAQuickness]

Thanks guys. I know these are some dumb questions but like your sig says, "You don't know what you don't know".

That's what we're here for. Feel free to fire away.


"...You think you know you knew you didn't think you knew you didn't..."


:eek: wow! My head hurts.....

yeah, that was rough Joe - but a good one just the same.

[dc_justin]

http://www.ls1tech.com/forums/showthread.php?t=287094
http://www.allmod.net/hpt/injectors.xls

What year is your truck 12sec? If it's a 99-03, then injectors are simple. Change your units in the edit/properties menu to lbs/min, then in the injector flow rate table, have a single value equal to the injectors you're running. 42/43lb 8.1L marine injectors?

[12sec.5.3]

It is a 99 with stock pcm. The injectors are from the 8.1 truck which I guess are 31lbs. When I installed them I just went to the Injector flow rate table and changed it from 19.xx to 31.

[dc_justin]

Sounds like your IFR is set up properly then.

Have you tinkered with your MAF or your MAF calibration table?

I've seen a de-screened MAF setup hit 15:1 at WOT when 12.5:1 was commanded. Screened MAF fixed it...

[12sec.5.3]

No, I haven't messed with the MAF table. MAF is de-screened and has been for a couple years. What should I do with it?

[dc_justin]

That's your problem then. De-screened MAF typically runs quite a bit lean. Hook your wideband up and do a VE tune, then MAF tune and you'll have it taken care of. If you have no Wideband, shoot me a PM, I'll send you a Maf calibration I have used on de-screened MAF trucks.

Justin

[12sec.5.3]

I have a wideband just didn't hook it up to efilive yet. I you don't mind, I'd like to take a look though. I know nothing about calibrating the MAF sensor.

[12sec.5.3]

The confusion continues.....
Last night on the way home from BR, with the cool front coming through and all, The wideband was back in the 12.7 region and the truck felt awesome. Maybe b/c the cool air, I don't know.