4g61t.org
http://4g61t.org/forum/

Datalogging
http://4g61t.org/forum/viewtopic.php?f=10&t=7414
Page 1 of 9

Author:  switch [ Tue Feb 10, 2004 5:00 pm ]
Post subject:  Datalogging

Hi guys,
I finally finished making my datalogger cable (all it is is one resistor and one diode!) after it took 2 months to get a new soldering iron!!!

Anyway - i've put in a 4g63t us spec ecu and am using TMO software to log on a laptop.

One strange thing I noticed was that my throttle position showed 11% at idle. Is this normal? On my safc it shows it as 0% (.55v i think it is)

I did a run on teh freeway taking the car up to 160kph and got 25+ counts of knock at anything over 4500 revs, which droppped the timing advance back heaps.

Im happy with my $5 investment :)

Can anyone shed some light on my throttle position reading?

Mike

Author:  The Ethereal [ Tue Feb 10, 2004 5:09 pm ]
Post subject: 

Just a diode and a resistor for a datalogger cable? :o Mommy I wanna have da schematic!
BTW that 11% TPS vs. 0% TPS is not normal. About 5% TPS should be normal.

Author:  switch [ Tue Feb 10, 2004 5:17 pm ]
Post subject: 

:) I will scan the schematic when I get home - the site I got it off is down!

I couldnt believe how simple it was either the first time i saw it. I was skeptical, but ive made it and it works :)

EDIT
Disregard my question guys, after a bit of research ive found that this is normal - it should be a little bit lower though (9-10% at idle) so i will still adjust it.

"Throttle Position:

Range: 0 to 100%
The position of the Throttle Position Sensor (TPS) on the throttle body. The % should directly corrolate to the gas pedal position. If the signal jumps around (usually happens at a single throttle position, but can happen at any time) then you could have a bad TPS sensor. This would cause bucking or hesitation while driving. The TPS signal should be about 9 - 10% at closed throttle. If it doesn't, a throttle cable or butterfly adjustment is necessary.

The Apex-i S-AFC uses the minimum and maximum TPS voltage it sees as 0% and 100% so the number displayed on the AFC will not match the TPS value on the PocketLOGGER. Since the TPS on a DSM never gets below ~10%, the AFC thinks that that value should be 0%. The ECU is smarter and knows that the TPS can go lower, but due to the mechanical design of the throttle body, the actual TPS value never drops below 10%."

Author:  switch [ Wed Feb 11, 2004 12:09 am ]
Post subject: 

Hey guys,
Follow the links for the schematics

This one is for laptops with a 9 pin serial plug
http://www.clubvr4.org/photos/Logger_Cable_PC.jpg

This one is for pda's
http://www.clubvr4.org/photos/Logger_cable_Palm.jpg

I have only made and used the laptop cable - im not sure if the palm one works but im guessing it does if the laptop one does!

Have fun making it and logging.

Mike

Author:  JMirage [ Wed Feb 11, 2004 1:15 am ]
Post subject: 

Where would a guy go for the software?

Author:  switch [ Wed Feb 11, 2004 2:52 am ]
Post subject: 

Go here for palm software - http://mmcd.meditprofi.ru/

For laptop software pm me

Mike

Author:  The Ethereal [ Wed Feb 11, 2004 9:34 am ]
Post subject: 

Dude I'm afraid that laptop cable can fry your ECU. The ECU uses +5V TTL logics there, while tha laptop has +12V. :-? Guess I should take my DMM and chek what my laptop really has there, but I bet it's 12V.

Author:  switch [ Wed Feb 11, 2004 3:23 pm ]
Post subject: 

Well im using it and it seems to work fine? and i know of at lest one other person who has been using it for months?

Mike

Author:  JMirage [ Wed Feb 11, 2004 9:04 pm ]
Post subject: 

Maybe it does use the 5v; as 12v, 5v, and 3.3v are all typically used in a computer.

Author:  JMirage [ Sat Feb 14, 2004 3:00 pm ]
Post subject: 

I found your answer @ vfaq.com

http://members.shaw.ca/dsm.1000q/Engineprimer/tps.htm
Quote:
Because of the way the TPS works, the reported throttle position will be different on an ECU datalogger and an aftermarket unit such as the AFC. When the throttle plate is fully closed, the TPS normally reads at 10%. The ECU "knows" this, and displays the correct number (10%).

Author:  switch [ Sat Feb 14, 2004 6:45 pm ]
Post subject: 

ThaANKS jMIRAGE - I found that about 10 minutes after i posted my question.

Mike

Author:  JMirage [ Sat Feb 14, 2004 7:06 pm ]
Post subject: 

oh, I was just reading around, and had remembered the original question, I suppose next time I'll read the whole thread

Author:  switch [ Sat Feb 14, 2004 7:17 pm ]
Post subject: 

haha - its cool

Mike

Author:  JMirage [ Wed Mar 10, 2004 2:36 am ]
Post subject: 

Well, I found out that the PDA schematic is no good. It dosn't even make sense, since the receive has a diode in line, there is no way for the PDA to get any info. Anyone else tried this?

Author:  switch [ Wed Mar 10, 2004 4:25 am ]
Post subject: 

Funny you say that :)

I finished making my Palm cable about 30 minutes ago and have been datalogging :) (Make sure you buy a male db9 connector for the palm cable as the hotsync cables have a female end on them)

It works a treat!

Ill take a pic and post it up

edit - here is a pic

Image

Mike

Page 1 of 9 All times are UTC-05:00
Powered by phpBB® Forum Software © phpBB Limited
https://www.phpbb.com/