confused Between VE and PE heeelp

[wesam]

I tried to search with out luck
i need some one to educate me and told me if i understand it the correct way
1- now the VE is used for part throttle and PE is used for Full throttle is this correct ?
2- if the car is rich ( some thing like 11.7 ) @ WOT will decreasing the 95-100 MAPs in the VE will solve the problem ? if yes i think there is some thing wrong as the area of 55-85 will be stoich and this will be too lean for WOT !!

[joecar]

wesam,

VE table provides airmass, PE table provides AFR... those are two orthogonal concepts... PCM always requires both airmass and AFR...

(in this context, "AFR" really means "AFR to command")

PCM follows this [simplified] sequence:
- calculates cylinder airmass from MAF and/or VE (see Note 2 below),
- looks up AFR to use:
-- in CL the AFR is stoich,
-- in OL the AFR is the richest of the active AFR tables (see Note 1 below),
- from airmass and AFR, calculates fuelmass,
- in CL adjusts fuelmass using trims,
- looks up IFR and injector characteristic corrections,
- from fuelmass and IFR, calculates injector on time and adds corrections,
- from airmass looks up ignition timing and corrections,
- fires injectors,
- fires spark plugs,
- in CL determines new trim values from O2 voltage behaviour,
- repeat.

Note 1:
PCM selects the richest AFR from the enabled/active tables...
For example say:
- PCM is in OL,
- the protection modes have not enabled,
- PE has enabled (via B3616),
then the active tables would be B3605 OLFA (since in OL mode) and B3618 PE (since PE enabled)...
the PCM selects the AFR from the richest of those two tables at the current operating point (i.e. TPS, MAP, RPM).

Note 2:
PCM calculates airmass from:
- above B0120: MAF,
- below B0120: MAF (steady throttle/airflow) and/or VE (transient throttle/airflow),
- in SD (MAF-less): VE.

:)

[joecar]

I tried to search with out luck
i need some one to educate me and told me if i understand it the correct way
1- now the VE is used for part throttle and PE is used for Full throttle is this correct ?
2- if the car is rich ( some thing like 11.7 ) @ WOT will decreasing the 95-100 MAPs in the VE will solve the problem ? if yes i think there is some thing wrong as the area of 55-85 will be stoich and this will be too lean for WOT !!When PE enables, PCM uses both VE (if MAF-less) and PE.

If rich (while in PE), then either of these will lean it:
- reducing the responsible airmass cells in VE,
- leaning the responsible AFR cells in PE.

The VE cells 55-85kPa provide airmass... B3605/B3618 provide AFR... from those PCM calculates fuelmass.

At WOT, what does your MAP read (or, what is MAP at key on engine off)...?

Post log files... do you have a wideband (sorry, I don't remember...? :doh2:)

[joecar]

The idea behind AutoVE is this:
- isolate airmass to come from VE table only,
- eliminate fuelmass trims,
- compare wideband AFR to commanded AFR,
- correct VE table so that on next run wideband AFR and commanded AFR become the same.

This means you set the commanded AFR to be suitable/safe for the operating conditions.

[wesam]

Joe my car is mafless tuned
my biggest problem that i put 80 lph injectors because i have FI in my future plans
and i could not make the car idle at 14.63
when it start it will be at 15 AFR then after 3 min it keeps decreasing until it stay @ 13.5
i will post a log and my tune today
thanks in advance