Having trouble connecting V4 to vehicle

[jfclubby]

Afternoon, Im helping a mate set up V4 scan and having trouble connecting, Its a VT supercharged V6 in a landcruiser comp truck. The memcal has been modified to not use the BCM in the conversion. The cable he purchased from ALDLcable.com for the OBD1 interface and downloaded the V4 evaluation software from the EFIlive website. Its showing inteface connected ok but not detecting any chatter. We have selected GMH-VT6 as the vehicle. We have hooked up a Snap On scan tool to see if there is a problem with the converted harness and everything works fine, We are able to see all sensor's cycling fine. Can anyone see why I cannot get any chatter from the ECM?

Below I have pasted the data when trying to connect,

56:43.593: Start macro: Clear diagnostic trouble codes: CLRDTC
56:43.609: Synchronising ALDL communications...
56:43.609: Waiting for heartbeat: $08,$55,$A3
56:43.609: Waiting for Aldl bus silence of at least 50ms...
56:43.776: Com timeout: Expecting frame header byte
56:43.798: Synchronising ALDL communications...
56:43.798: Waiting for heartbeat: $08,$55,$A3
56:43.798: Waiting for Aldl bus silence of at least 50ms...
56:43.963: Com timeout: Expecting frame header byte
56:43.986: Synchronising ALDL communications...
56:43.986: Waiting for heartbeat: $08,$55,$A3
56:43.986: Waiting for Aldl bus silence of at least 50ms...
56:44.151: Com timeout: Expecting frame header byte
56:44.175: Stop macro: Clear diagnostic trouble codes: CLRDTC

Any help would be appreciated

Regards James.

[Blacky]

Sometimes the COM port you have selected in the EFILive software is actually the COM post used by the built in modem.
A modem can appear to the EFILive software the same as an ALDL cable so it appears to "see" the cable when in fact it is seeing the built in modem.
Make sure your ALDL cable is really using the same COM port that you have set up in the EFILive V4 software.

Regards
Paul

[jfclubby]

Thanks Paul,

With a little persistance yesterday we finally got it working. The engine is internally stock with a slight overdrive increasing boost to around 9PSI and the thing is running extremely rich, while logging yesterday we are noticing that the MAF goes off the scale (300+ grams/sec) and looses signal at around 17% throttle with no engine load (sitting in the shed). I would think this is telling the ECM there is more air flow than there really is and then the ECM commanding the extra fuel it thinks it needs and resulting in the rich condition. How is the ECM fueling correctly when the MAF signal is effectively out of range, Even with the MAF unpluged at idle it still logs around 90-100 grams/sec Your thoughts please Paul?

Regards
James

[Blacky]

I have zero experience tuning the VT V6 so there's not much I can help with there, sorry.

I don't know if this is the same for the V6's but on the 5.7 liter LS1 controllers the ECM usually compares the air flow rate measured by the MAF to an internally computed air flow rate based on MAP and RPM.
If the MAF signal differs by too much then the ECM assumes the MAF is incorrect and uses the calculated air flow instead.
Its what is known as speed density tuning and many tuners will deliberately disable the MAF to prevent it pegging under boost.
Then they use the computed speed/density air flow to tune the fueling.

Regards
Paul

[RBR]

James

I hooked a snapon scan tool up to the ECM and it seems to be reading correctly. I then hooked EFI V4 back up and it is reading the correct frequency however when that frequency is converted to g/s is where the readout seems to be getting mixed up. The xml that I am using I downloaded from L67 torque forum (gmh-vs-Super-6.xml) I'am not sure weather this is the problem. What xml should I be using for a L67 VT Engine.
Any help would be appreciated

Thanks Bloomer

[Blacky]

What does the MAF g/s show when you use the gmh-vt6.xml file?

Does the xml file you're using have the same configuration for the MAF g/s parameter?
Compare with the image below.


Regards
Paul

[kangsta]

try changing the scaling factor to 0.0625 for the MAF airflow. The old PCMs in the L67s dont have a map sensor on the factory OS so MAF is the primary fuelling. Factory L67 tunes run into 11:1 AFR. If the memcal is running a custom OS the datastream may be shifted slightly so the values wont line up with a standard datastream def. Also try cleaning the MAF with contact cleaner spray

Paul, I think all the VS onward defs in v4 have the incorrect scaling for MAF airflow. See here http://forum.efilive.com/showthread....nfo-inaccurate

[RBR]

Hi Paul

When I try to use the gmh-vt6.xml file I get the following eror.

08:06.286: Opening COM4 8228,8,N,1
08:18.876: Start macro: Engine data: DATA
08:18.875: Synchronising ALDL communications...
08:18.875: Waiting for heartbeat: $08,$55,$A3
08:18.875: Waiting for Aldl bus silence of at least 50ms...
08:19.046: Com timeout: Expecting frame header byte
08:19.069: Synchronising ALDL communications...
08:19.069: Waiting for heartbeat: $08,$55,$A3
08:19.069: Waiting for Aldl bus silence of at least 50ms...
08:19.233: Com timeout: Expecting frame header byte
08:19.256: Synchronising ALDL communications...
08:19.256: Waiting for heartbeat: $08,$55,$A3
08:19.256: Waiting for Aldl bus silence of at least 50ms...
08:19.421: Com timeout: Expecting frame header byte
08:19.446: Stop macro: Engine data: DATA

I checked the parameters and they are the same.

Thanks Bloomer

[Blacky]

try changing the scaling factor to 0.0625 for the MAF airflow. The old PCMs in the L67s dont have a map sensor on the factory OS so MAF is the primary fuelling. Factory L67 tunes run into 11:1 AFR. If the memcal is running a custom OS the datastream may be shifted slightly so the values wont line up with a standard datastream def. Also try cleaning the MAF with contact cleaner spray

Paul, I think all the VS onward defs in v4 have the incorrect scaling for MAF airflow. See here http://forum.efilive.com/showthread....nfo-inaccurate

Thanks for the reminder Kangsta, I had forgotten about that thread.
Bloomer, try doing what Kangsta suggested, changing the scaling to 0.0625 for the MAF g/s paramater.

Regards
Paul

[kangsta]

No worries Paul. I cant wait till ALDL is integrated into v8

Cheers,
Ben