MAFS issues

[glacier985]

Okay, here is the rundown. I'm trying to get a good base tune on my car before I take it to the dyno to get fine tuned. The setup...

Nistune ver1
TechEdge 2E0 wideband
Stock KA24e
Stock MAFS
460cc injectors (cleaned, flow tested by DeatschWerks)
T3/t04e 57 trim .63 a/r
Tial 38mm Wastegate set a .5 bar
DSM 1g BOV

Now what my problem is, at idle the log on nistune reads my TPS at 0.46 volts, but my MAFS at 3.099 volts. TPS is fine from what I've read, but the MAFS seems to be 2 volts higher then it should. I did a very minimal second gear pull (while logging, before I saw the MAFS voltage) to get a idea of where my tune was at. Well needless to say the car stalled and sputtered and the wideband went rich. After checking the log, the MAFS voltage hit 7.989 volts on that pull. Not sure what is going on with that, but I know it is not right. I'm looking for help figuring it out.

[Matt]

There is an artificial addition done for RB30 and VG30 MAFs inside Nistune to represent what is seen at the AFM input of the ECU. This is determined by the address file used and current VQ Map selected

So normally the address file for these engines has an offset
LEGACY_AFM_OFFSET=1500

But if the MAF is not R31/Z31 then this gets changed to 0

In your case it looks like its getting used but doesnt make sense. Can you post your BIN file here. What VQ map (under Change MAF) is selected?

What is the physical voltage on the MAF connector in the vehicle whilst the engine is running?

[glacier985]

Okay did some checking, here are my results.

Ignition on, car not started

Nistune shows 1.6ish volts
MAF B wire shows around 0 volts

Ignition on, car running at idle 1k rpm

Nistune shows 3.6ish volts
MAF wires
A - 14.36
B - 0.80
C - 2.50

Here is my bin, which has the MAF unchanged since I'm using the stock one. I have also posted up my log file as well. I also double checked that I am using the correct adr file, which is the s13 ka24e one.

[glacier985]

Ok, back with some more info. I checked the pins on the ECU and when using the MAFS ground (at the ECU) I get a reading of 1.6-1.7 volts. Now comes the strange part, when checking at the MAFS itself I the same (using the MAFS ground instead of the battery ground) I get a reading of -0.7 to -0.8 volts. Then when I have just the negative terminal of the multimeter on the MAFS ground and the positive multimeter terminal just in the air I get a reading of around 1.8 volts. So something seems to be screwed up on my harness of MAFS. But if anyone has any other things I can check I will look into those as well.

[glacier985]

So any ideas? Is it possible its the ECU? I'm looking for anything here, I want to get my car tuned sometime.

[Matt]

Was this for J30 Maxima? I found an issue where AFM reported from the ECU is double the real voltage. I've added a change this week to fix that and incorrect ignition time. Should have a release next week for this one

[glacier985]

Was this for J30 Maxima? I found an issue where AFM reported from the ECU is double the real voltage. I've added a change this week to fix that and incorrect ignition time. Should have a release next week for this one

No its for a ka24e 240sx, but the ECU is saying that its 3.6 volts and when I measure it at the pins on the ECU it tells me that its 1.7-1.8 volts. It just so happens that 3.6/2 = 1.8, that is very strange

I've been trying to find a stock 240sx to let me plug the ECU into there car and see what reading I get, but I can't seem to find anyone.

[Matt]

Okay that issue affects reporting of consult on
J30 VG30E, S13 KA24E, A31 RB20, D231 VG30E, D21 KA24E

Just halve the value for now and next version will have this fixed up