The Tuning Talk Thread - Forced Induction EFI & JZ Tuning.

[jdm93]

I has question(s) if someone could possibly help :$ ?

OK I'm going to start uploading all the problems now. Need to make a plan for the stall situation.

Problem #1: The noise and fluctations in the GReddy pressure sensor input. I have fixed problems like this before with a small flow restrictor and a pressure can before.



Problem #2: The wb02 gauge analogue output is not yet fed back into the E-manage option input. So no AFR datalogging.

Problem #3: The timing is doing odd things and for no apparent reason





Problem #4: The factory tune seems to do this wanky Texas Holdem "I'm all in" with the fuel. Looking at the wb02 gauge while watching the injector duty on the laptop. The injector duty seems to basically race straight to 100%. At the same time the wb02 gauge is railing out at full rich 10:1. Even when The only change is clamping the MAF to 4.2volts in the top end. Anyway, after a few parts of a second the injector duty seems to drop back to 0% for a short period. Looks like an ECU reset. Will have to check if thats what the GReddy is meant to do. If so just getting some injector in it should fix that. Either way its clear its got the fuel and its going to hold together.

any suggestions ?

[JP]

the greddy map sensors usually come with a filter that should smooth out the reading. The filter looks just like the two clear plastic filters in this pic: http://2.bp.blogspot.com/_vBqLJNBqOX...oller+evc6.jpg

The timing drop in the section highlighted wtih blue doesn't look to be knock related, need to know what the lower value is to get a better idea though. When they knock most of the advance comes straight out, not gradually like shown in the graph.

the vvti 1J's always run pig rich under load when modded.

[thechuckster]

fwiw: a mig welding nozzle (edit: contact tip) anywhere from 0.6 to 0.8 stuffed into the flexible line anywhere before the map sensor will also 'filter' a noisy signal.

[1JZ-Rolla]

Never thought of that one chuckster, good idea. I've used small 6mm fuel filters before also, after a local tuner put me onto the idea. At least your method will never fail, unlike a plastic filter which I assume will eventually fatigue from cycling between pressure and vacuum all of the time.

You mean "contact tips" though right? Might be a bit hard to fit the nozzle into a hose line

[OnAll-FOUR]

Mecahnical smoothing Vs Electronic filters in the ECU's?

Is that distortion in the MAP signal actually noise? or does it represent what is acutally going on and therfore should be used as is?

[1JZ-Rolla]

Usually represents what is actually happening in the manifold, and so can be useful, but without any form of signal conditioning can be a PITA with parameters like boost cut, if the fluctuations either side of average are particularly wild.

[thechuckster]

1JZ-Rolla: oops, contact tip is the right term.

OnAll-FOUR: the restriction helps reduce (tho not eliminate) the pulsing you'll get from: massive throttle changes (often at slow air speeds), pulsing from short runners (e.g. ITBs) and aggressive cams (especially at low revs). Is also helpful when you have an ECU that doesn't do any 'smoothing' of engine state sensor input.

Example: engine at low revs and minimal load, throttle is suddenly pushed to 100%, ECU will pickup on the TPS change and enrich based on acceleration settings, MAP will briefly fluctuate until the plenum stabilises to the new vacuum state but will continue to be affected by pulses travelling up/down runners leading to each valve. End result is an engine under load with minimal changes in RPM until the accel enrichment does it's thing, low and variable MAP contributing to highly variable inj pulse-widths and possibly also timing. At higher engine revs, the faster air speed into the plenum and higher frequency of runner pulses has far less effect on MAP noise.

Engines with ITBs on short runners suffer from noisy MAP signals - especially if only one port is used for MAP reference. Hence the use of ports on each throttle and some kind of balancing chamber to combine the 'signals'.

Remember that this tricks helps most when where you have quite short injector pulse widths. At idle, minor changes in PW will have a fairly dramatic effect on the amount of fuel delivered (e.g. at idle, INJ open time might be 2 m/s, variations of 0.1 to 0.2 m/s will deliver 5-10% more fuel, at larger opening times, the same variation is negligible in comparison).

[rpsil13]

Hi guys joined this forum b/c i saw australians are far more familiar w/ the microtech ecus,

my setup

1jz w/ 550's (mk4's) and 67mm (TO4Z) turbo, big front mount, walbro pump, microtech lt12s w/ x6 ignition box



here are my numbers from the hand controller if anyone wants to chime in an help me,

right now i have a sligth misfire, which i think are the spark plugs, so im going to change those out

also i got my idle to be 14.7-15 AFR, but as i rev it kinda leans out to 15/16, which screen should i use to add fuel

Microtech tuning
Af_StE 25% (after start enrichment - starts at 25% and decays over a set time)


Crank (steps in Degrees Celsius, adjustment values as percentage)

-25 +74
-17 +68
-9 +63
-1 +58
5 +60%
11 +60
18 +50
24 +38
31 +25
38 +20
46 +20
60 +20
68 +20
82 +20
99 +20
124 +0



Water (Coolant temp Degrees C, adjustment values as a percentage)

-16 +26
5 +60C
11 +50
18 +42
24 +32
31 +22
38 +20
46 +19
60 +17
68 +15
82 +07
99 +00


IDLE (Inches Vacuum [HG] adjustments in injector milliseconds [ms])
30" 0.38
24 0.52
18 0.71
12 1.05
06 1.76
00 2.05


Timing at IDLE: 18 degrees

PUMP1
Amt: 5%
Pulse: +08
Trig: +16
Stop: 05" HG


PUMP2
Start: 2500rpm
Amt: 7%
Time +06
Trig: +25
Stop: 00" HG


PUMP Cold: 80%

Main fuel LOAD map

24" 0.52
18 0.76
12 1.33
06 1.86
00 2.29
2psi 3.00
4 3.71
8 4.76
10 5.48
14 5.95
16 6.43
18 6.81
20 7.19
24 8.67
28 9.29

To RPM
Idle +18o
1000 +24
1500 +24
2000 +24
2500 +26
3000 +28
3500 +28
4000 +23
4500 +19
5000 +19
5500 +25
6000 +26
6500 +35
7000 +35
8000 +33
9000 +30


ToMap
Idle +18o
24Hg +0
18 +02
12 +0
6 +0
0 -2
2psi -4
4 -6
8 -8
10 -10
14 -14
16 -16
18 -16
20 -16
24 -18
28 -20


Aux (which after reading I don’t think I even need this)
2psi -338
4 -4.24
8-4.57
10 -5.19
14 -5.95
16 -6.67
18 -7.24
20 -7.81
24 -8.43
28 -8.95

Also on my hand controller my TPS reads +99% is this normal? Or do I need to calibrate it, if so how

Any help greatly appreciated

Thanks



TIA

[1JZ-Rolla]

hey mate. Do you have the Microtech manual? It will tell you how to calibrate the TPS.

[VA61DETT]

-rpsil13

I have an LT10, its a dog to get idle working nice...
I can barely get my engine to idle at AFR greater then 12...

To enrich the throttle 'transitions' up the levels of 'PUMP1' & 'PUMP2' 'AMT'
It looks like you are using throttle triggering for the pumps, so you will need to have the analogue tps hooked up correctly.

The TPS should automatically calibrate when you turn the ignition on (not running) & press the accelerator all the way down.
The yellow led on the ECU should be steady lit, indicating calibration mode.

Use a multimeter to check that the tps line (Grey) is varying in voltage as you press the accelerator. (will be around the 0-5v range)

Let me know if you need a copy of the manual.

Regards
-A

[1JZ-Rolla]

Hey VA61, not being impolite, and please don't take this as a criticism, but in the interest of accurate information for rpsil13, where did you get that info about fuel pump & TPS calibration?

[VA61DETT]

My Bad with the TPS cal!
I was getting confiused with another system.
Just got home & checked the Manual for clarification:

MT Manual Extracts:

(TPS Cal)
"TPS sensor must be calibrated. Scroll to the TPScal screen in the
OPTIONS function (Screen 30).
If your system is fitted with a switch type TPS, you will need to loosen the screws mounting the
TPS onto the throttle body, and physically turn the TPS until the TPScal display reads 0%. Retighten the TPS in this position and
check the calibration by softly touching the accelerator pedal - as soon as you touch the throttle, the TPScal value should change
from 0% to 99%.
If your system is fitted with a variable resistor type TPS, switch the Handset into PROG mode and with the throttle closed (foot off
the pedal), use the up/down ADJ buttons to make the CURRENT display in the TPScal screen read 0%.
NOTE: With the ignition switched on but the motor not running, the yellow lamp on the side of the MT ECU acts as a TPS
calibration indicator and will be lit while the throttle is closed (0%TPS)."


(Pump1, Pump2)
Now adjust for throttle response and to remove any flat spots using the Pump functions
(Screen 19). Remember that the MT ECU has two accelerator pump functions: Pump1 for
below 2000RPM and Pump2 for above 2000RPM.

-A

[rpsil13]

thanks guys, yes i do have the manual but was unsure if the jz tps was switch type or variable resistor type

so far i was looking at the wiring and noticed that my ground wire (brown) on the tps is broken, so i am going to fix that this weekend and see if that changes anything,

also ive been looking online to see how to properly wire the tps? so far i have learned that the microtech ecu only uses 2 wires (grey and blue)

what i have so far:
brown-ground
yellow w/ blue stripe- nothing
white w/ red stripe- grey MT
blue w/ black stripe- blue MT

thanks for all the help

[midnight_purple_GA70]

Ok ive got some figures in from my microtech for

t*RPM
idle = 19*
1000 = +13*
1500 = +20*
2000 = +30*
2500 = +32*
3000 = +32*
3500 = +32*
4000 = +32*
think it might come down a little in the higher rpm

for t*map or whatever it is
2psi = -2*
4psi = -3*
8psi = -6*
10psi = -8*
12psi = -10*
14psi = -12*
16psi = -14*
18psi = -16*
20psi = -19*

now just to confirm how this is working and what it is doing
the t*rpm is the base timing map so from 1000rpm its 13 degrees btdc and from 2500 on its 32 degrees btdc
at about 2500-3000 is where im starting to see positive pressure which is where it should switch and start looking at the t*map values?
so at 2psi i will be running 32 degrees btdc minus the 2 degrees btdc in the t*map which = 30* btdc
as boost and rpm increase this then drops down from 30* btdc to 13* btdc at 20psi

or have i got this all wrong in my mind?

[1JZ-Rolla]

Your logic is correct there, but looking at those numbers, bump that base timing up at 1000rpm mate. No idea why your tuner would have the timing drop away from idle speed as it accelerates through 1000rpm. About 20degrees advance should do the trick at that point.

What figures are in the rest of your t*map screens, below 2psi? The rest of the ignition retard figures on boost look 'ok'

Have you confirmed your base timing with a timing light, to be sure that what you see on the Mtech handset is actually what the engine is doing?

CHeers