Finally, first VEMS install.

[Lizard]

Ok so I have gotten a VEMS unit and am installing it onto a 1990 928 GT.

I have a couple of questions though, which going through the manual didnt seem to be really covered.

#1 is with regards to the IAC. The 928 uses a 2 wire Bosch IAC. I have used this valve with Megasquirt and it works on the PWM style IAC without any problems. But I am not sure as to which port to use. IE use inj g/h to drive, or 1 side of the 4 wire outputs on the 18 pin plug?

#2, the 928 has a vacuum actuated butterfly (flappy) used for resinence tuning. This uses an earlier version of the GM style boost control valve (same but different connector). I am needing to know what ports (preferably inj e/f in the 36 pin) I can use to drive this. I need to actuate it at a specific RPM, and hopefully turn it off after a specific RPM too.

#3 the 928 tachometer runs off of 1 of the 2 coils. This means it reads like a 4 cylinder. I am doing fully sequential COP on this car and would prefer to use a spare output port as a tach signal. Is this possible? Or do I need to tag into the signal lines with diodes (to prevent backfeed) to get my tach signal?

#4 there is also a factory fuel consumption guage in the car, it works off of the injector pulsewidth. Now the stock system has only 1 injector driver which fires all 8 injectors at the same time. So the pulsewidth will be VERY different from running 4 injector drivers (more spares) each powering 2 injectors. Could I program a spare port to output this signal as well? Or how would you recommend that I attempt to adapt this system?

TIA!

Colin

[Lizard]

I also wanted to mention that I think it would be a wise idea when purchasing the harness to include 2 6M piece of 2 pin shielded (3 wire total) wire, with or without ends. As this is really needed, impossible to find locally, and not currently included. 

[gunni]

#1. Use one of the free ign/inj output.

#2. use a relay output as it´s just a open/closed scenario it seems.

#3. You can adjust the multiplication of your tacho signal in the software to suit your tacho.

#4. This consumtion thing is not working right now but should only be a firmware upgrade away.

[Lizard]

Thanks Gunni for the quick reply.

Though I have another question.

Which pin is Tach output?



I dont see it in here. And going through the manual didnt find a reference for it either 

Good to know that the consumption is being worked on. Which pinout will it likely be on?

Thanks again.

[gunni]

Tacho would be on one of the lime green P259 channels.
A consumption output would be on one of them as well.

[PeepPaadam]

Hi Colin!
Best place to connect tach is EC36 pin4,  which is P259 channel 0 as this output has 1K pullup soldered already from the factory and tach will work properly, did that on two 928's already. With two Bosch 2x2 coilpacks (wasted spark) I used tach divider 32. 

[Lizard]

Thanks for the help guys,

Good info thanks Peep, I would have asked you on MSN but neither you or I have been on much :p

I am using sequential COP. This is on a RHD 90 GT for those with interest.

Peep if you happen to know as to the exact settings I need to input for the 60-2 ring it would be appreciated.

Thanks again

[PeepPaadam]

It would be like this, but you have to verify the TDC after the trigger position with the strobe and when using 1.1.x firmware, also fill the reference tooth table:

[Lizard]

Well I have gotten most of it setup and working with the entire loom in the car and complete.

I need to make only 1 change to get my PWM ISV to function.

I have upgraded the unit to 1.0.73 firmware.

There is only a couple more questions,

Trying to use the mini terminal to do anything does not seem to work. I type in MAN and then it spews out a ton of nonsence.
Due to this is there any other way to calibrate/setup the WBO2 sensor? The voltage between pins 5/6 is .06V which from looking at the manual is probably as low as I am going to get. But as stated I cannot type anything commands in the box and get anything useful out of it.

I also wanted to know if there was a base VE table generator hidden somewhere for the VEMS. I have used this for MSII previously and it worked well to get me started and going.

Thanks again.

[rob@vems.co.uk]

Use the Terminal app - its in the Tools directory of the software you downloaded, you can't run MegaTune at the same time though.

As MegaTune takes the same Map format regardless of ECU type you can use the same map tools, most people like to use MegaLogViewer for all the map fiddling.

[s14nismo]

There is only a couple more questions,

Trying to use the mini terminal to do anything does not seem to work. I type in MAN and then it spews out a ton of nonsence.
Due to this is there any other way to calibrate/setup the WBO2 sensor? The voltage between pins 5/6 is .06V which from looking at the manual is probably as low as I am going to get. But as stated I cannot type anything commands in the box and get anything useful out of it.

This one had me stumped for a while,

Make sure you type Man into terminal, its case sensitive, man or MAN wont work

[Lizard]

Thank you S14 for that.

And I got the terminal tool and had the same trouble in that.

Though S14 has got me fixed with the one problem.
Now that I can do that....

I am still stumped on a few things. 

After doing a bunch more reading I thought I had figured out how to get the clt and ait sensor information in to be able to get the computer to read them (both Bosch unit). After trying to fight with it for a good deal of time. Is there somewhere that is a step by step guide for the temp senders???

I got the VE table and everything else sorted more or less.

I just need to get those done and get a short piece of hard vacuum line to run into the interior for connecting to the unit which is easy.

And I goofed, I dont have 1.0.73 its .78 I grabbed. But I am curious as to which firmware you guys might recommend?

[PeepPaadam]

1.0.73 and 1.0.78 are both good starting points.

As for temp sensor calibration, 928 needs 2063_256 for both CLT and MAT, so take your "upload_tempsensor.bat" (16x14 version preferrably), open it in Notepad (right click -> edit) and change all of the empty CLT and MAT file locations with those. Also check that COM port number in bat file is the same what you're using in your laptop. Then execute the .bat and wait until it's done.

[Lizard]

Switched to 1.0.73 final as after getting the spark to work using the stepper outputs I had no inj PW from the corrected MSQ I had Peep help me with. (thanks again Peep!)

Once that was done car fired right up. Needed some help as the MAP connection had popped off though. LOL

It is probably something in the MAT correction that is causing that and I will be figuring it out and possibly going back to .78rc2