Help to tune at idle to avoid a lean condition using MafPro

[CarlosPTR210]

Hi,


I install the Maft Pro with version 5.22 in to my 91 Supra,


( By the way, how can I make teh HAC mod to the ecu? )


But have few issues that I want to be fix before tune under boost.


The main Idea is to keep the stock ECU working in close Loop, so I need adjust the Mafpro to achieve that.


To verify it, I use the Aux 1 in the Pro, to check the Vf voltage from the ECU.

The problemems that I have are the followings:


1.- Engine at idle very lean

A/F: 15 to 16

Aux 01 = Vf: 4.43

2.- Drive the car with light engine load:

A/F: 14.5 to 15.5

Aux 01 = Vf: 3.3

3.- Drive the car with more aggressive engine load:

A/F” 14.5 to 15.5

Aux 01 = Vf: 0.9

What do I need adjust, to add some fuel at idle and light throttle?

What do I need to adjust, to remove a little fuel in middle throttle?


The engine is stock, no other mod.

Stock 440cc injectors

Stock Turbo and intercooler

Walbro fuel pump.


Thank and best regards.

 

[GrimJack]

No adjustable fuel pressure regulator to go with that walbro fuel pump?

Doing the HAC mod on your ECU is not an easy bit of work. You'll need a very steady hand with a soldering iron, and even then it is extremely touchy. The guys who make the MAFT Pro will do it if you send it to them, and if you have any doubts about doing it yourself, I highly suggest taking advantage of this.

 

[CarlosPTR210]

No adjustable fuel pressure regulator to go with that walbro fuel pump?

Doing the HAC mod on your ECU is not an easy bit of work. You'll need a very steady hand with a soldering iron, and even then it is extremely touchy. The guys who make the MAFT Pro will do it if you send it to them, and if you have any doubts about doing it yourself, I highly suggest taking advantage of this.

Nope I don't have a adjustable fuel pressure conected, I have a one but i need to buy the hose.

With the AFM conected never have the problem, that wahy I think that I need to modify some setings .

So any sugestion?

 

[TurboStreetCar]

Youll want to tune the car in closed loop to satisfy the VF reading. VF is fuel trim, it outputs in steps. 2.5 is where you want it to be at all times in closed loop. The Higher the voltage the more fuel the TCCS is adding to initial mixture to compensate. The lower the voltage the more fuel the TCCS is PULLING to compensate.

At idle the mixture is a little lean, and the VF is high. You need to add fuel to that area untill the VF stabilizes at ~2.5 volts.

Light load the VF is still a slight bit high, you'll want to add a little bit of fuel in that area as well to bring the VF to ~2.5 volts.

When your at WOT or under a good amount of load the TCCS will go into open loop. When in open loop (in my experience) the VF will drop to ~0 volts. This is the time you want to do your tuning.

Since you have stock injectors and stock turbo i would say to zero everything out and start from scratch. Since you have stock injectors the tune will not need to be changed much from stock besides leaning out WOT up top a bit for some more power and to raise fuel cut a bit.

 

[CarlosPTR210]

Since you have stock injectors and stock turbo i would say to zero everything out and start from scratch. Since you have stock injectors the tune will not need to be changed much from stock besides leaning out WOT up top a bit for some more power and to raise fuel cut a bit.

Ups sorry, I forget to add me set up.



OK, because I have the engine stock, the mainscale is at 0.

But my doubt is what setings need to change, to try keep the Vf to 2.5?


Thank!

Source Definition: TPro500Vehicle2.xdf
Vehicle Select 00
Number of Cylinders 6
Displacement 2.96 Liter
Airflow Source 0x00 Select
Manifold pressure source 00
Load Source 0x00
Barometer Comp Mode 01
Frequency Out Mode 0x04
V Out1 Mode 0 Select
V Out2 Mode 0 Select
AFR Source 3 Select
Freq In Mode 0
Aux 1 mode 00
Main Scale 0.00
Volts Out 1 Limit 2.51 limit
Volts Out 2 Limit 3.61 volts
Afterstart enrichment 0.00
Tune Load Point, Low 36.40
Tune Load Point, Mid 100.10
Tune Load Point, High 143.00
Freq Out Max 0
Timing Monitor, Base Adjust 0.00
Timing Monitor, Correction 1.27
FE Smoothing 30

AFR Min TPS 2.46
AFR Min RPM 1760
AFR Min Load 49.43
AFR correction lean limit 5.00
AFR correction rich limit 5.00
AFR correction gain 2.00
AFR Aux % 0.00
AFR Tracking, Enable delay 1.50 Seconds
TPS Enrichment 0.50
TPS Decay 0.80
Throttle Body Size 7
TPS MAP Max 97.56
MAP Enrichment 0.50
Boost Enrichment 0.40
MAP TPS Min 0.48 Volts
MAP RPM Min 1024.00

Part Throttle Tracking Idle A/F Ratio 14.40
Part Throttle Tracking Cruise TPS 0.00
Part Throttle Tracking Cruise RPM 2560.00
Part Throttle Tracking Cruise Load 91.05
Part Throttle Tracking Cruise A/F Ratio 14.50
Part Throttle Tracking Lean Load 84.55
Part Throttle Tracking Lean Delay 10.00
Part Throttle Tracking Lean A/F Ratio 16.00
Part Throttle Tracking Gain 15.00
Part Throttle Tracking Startup Delay 74.51 Percent
Enhanced TPS RPM threshold 4800.00
Enhanced TPS Load Threshold 188.24 KPA

 

[TurboStreetCar]

Im not very familiar with the software but there should be a place to change a value on a table of some sort.

I see you have load points, thats the same setup i had on the MAFT GenII and i could go into the load table and add or subtract a percentage of fuel based on RPM point on that load table.

Best answer would be from someone who is running or has run the Maft Pro. Im sure someone will chime in with more information or instruction.

 

[GC89]

youll need to go into the ve tables, there is one for low, mid, and high loads. You have to look at the logs to see which areas of the table need tuning but I always use the multiplication tool to make small adjustments. Multiplying by .98 or 1.02 so you can just click and it will gradually adjust up or down.

 

[dbsupra90]

what is your base fuel pressure (no vac)?

the part throttle tracking crap always fought with me. i'd try to disable it or use an older version. i have several on my site for you to try if you'd like. atleast try to eliminate any of that causing an issue.

 

[CarlosPTR210]

what is your base fuel pressure (no vac)?

the part throttle tracking crap always fought with me. i'd try to disable it or use an older version. i have several on my site for you to try if you'd like. atleast try to eliminate any of that causing an issue.

The fuel presure is stock with vac conected.

I think the PTT is disable!, or don't? :aigo: