99 5.3 4x4

[drdiesel]

99 5.3 chevy 4x4 cold air kit ok guys im tuning my frist gasser.
witch table controls the main inj. pluse and witch table do i use to adj for the cold air kit?

theirs so many i just want to make sure im in the right table.

and what kinda tuning r u guys doing to the tranny?

also is their any thign like a dsp2-5 for the gassers?

[joecar]

Hi drdiesel,

the PCM calculates cylinder airmass, looks up the AFR to use, calculates the fuelmass needed to meet this AFR, looks up the IFR and calcuates the injector pulse width needed to deliver this fuelmass...

so basically you could:

- edit the IFR table B4001: this table is referenced by MANVAC, so you would basically be "tuning" for a small subset of operating conditions and "untuning" everywhere else;

- edit the MAF table B5001: the PCM uses this to compute cylinder airmass based on air flowrate and RPM, but there are times when the PCM uses the VE table...

- edit the VE table B0101: the PCM uses this to compute cylinder airmass based on manifold pressure and RPM... then PCM uses this table when it's not using B5001...


since everything is part of a "chain" there never is any easy answer...


Some more notes:

Wideband reports the same AFR as commanded AFR if these are all true:
1. B4001 and injector tables are correct,
2. When PCM uses VE: B0101 is correct,
3. When/if PCM uses MAF: B5001 is correct,

The various protection mode AFR's are reflected in the commanded AFR.
The PCM selects the richest AFR from the tables active at that moment.

PCM calculates airmass from:
- above B0120: MAF
- below B0120: MAF (steady state throttle/airflow) and/or VE (transient throttle/airflow),
- in SD (MAF-less): VE.

PCM determines AFR from:
- CL: closed loop feedback trimming to stoichiometric AFR (B3601),
- OL: the richer of: B3605, B3647 (COS), and B3618 (if PE has enabled from B3608-B3616).

PCM uses OL:
- when cold,
- at WOT,
- during throttle/airflow transient conditions,
- if CL is disabled.

VE/MAF determine airmass.
OL/CL determine commanded AFR.

SD/MAF are orthogonal to OL/CL (there exists 4 combinations of these).

PCM also uses airmass to determine ignition timing and transmission pressure.So the best thing to do is to first take some logs and look at what effects the CAI kit is having on trims and timing, and then determine how far you want to tune...

:)

[drdiesel]

yeah tell me about it. is their any one that would like to give me a helpin hand? and one more thing you know the air/fuel ratio thing you can get at adv. auto and auto zone,are they what you guys calling "wideband o2's " thanks

[joecar]

Post some logs.

[drdiesel]

heres the tune from the truck im workin on. forgot to get the loggs from my partners laptop.