MPGuino installation/calibration help

[asdrewq1]

hi everyone

I picked up a preassembled mpguino recently from a member on this forum, and got it installed today in my 1996 Toyota Celica GT-Four.

I have managed to calibrate the speedo input perfectly, on the screen which displays the current speed it is pretty much bang on, I am however having an issue with the injector setting.

I hooked up the injector wire to one of the injector outputs on the engine ECU.
My issue is, the mpg readout seems to be acting in reverse! I'm using the instant mpg screen to try and calibrate the reading to a rough ballpark of being correct. When I put my foot down when cruising on the highway the instant mpg goes up! Likewise when I drive slowly it drops. When I take my foot off the accelerator completely the instant mpg shows 9999999 which I think is correct (deceleration fuel cutoff).

Can anyone offer any advice as to what could be wrong? I've played around with the settings but it still seems to be operating in the reverse of how it should be.
One of the displays on my mpguino is a rpm readout, and this displays correctly, so the injector signal feed must be kind of working.

Could it be one of these options in the menu?
- injector type (0, 1, 2)
- injector delay

Thanks for any help. I have a big roadtrip planned in 8 hours and would really like to get it operating correctly by then so I can calibrate!

[asdrewq1]

I think i've found the problem - I didn't check the voltage on the injector wire with the ignition in the 'on' position, and it is +12v. I thought i'd be ok taking the feed from the wiring on the ECU in the cabin. Am I right in thinking i now measure the voltage on the plug on an injector, and connect it to the one that shows 0 when ignition is on?

Bit of a pain, I didn't want to tap the wiring loom in the engine bay

[asdrewq1]

Managed to find the wiring diagram for my car showing the injectors:

Forum won't let me post links, but if you paste this in address bar you can see it:

gtfour.supras.org.nz/pics/ECU1.pdf

I have tapped the injector on the right hand side of the injectors on that diagram, between the injector and the ECU pins (top of the page). If i'm reading it right I have connected in the right place? The other injector wire leads to the EFI resistor, ignition switch, fuse and battery +ve.

[meelis11]

Try to change injector type from 0 to 1.
PS! just in case restart (disconnect power) mpguino after changing injector type - otherwise change does not get applied

Meelis

[AndrzejM]

On the settings screen of MPGuino there is option saying inj up or down - change it to the other setting that you have now and that should solve your issue.

[asdrewq1]

Thanks meelis! i think i've fixed it now. I wasn't pulling the power lead before, just tried it and it looks like injector type 0 is now working for me. Just curious, what parameter does the injector type setting affect?

[AndrzejM]

This setting tells guino if it should wait for high or low state. So when you've change it you've changed your guino to count injector open time instead of the time when it was closed.

That's why you had reverse readings.