rusefi.com

I made a short video and posted it on YouTube:



- Electronic Gas Pedal Assembly with Bracket Position Sensor 19417903 Compatible with 2005-2013 Corvette C6 Gas Accelerator Pedal 25835421 15864594 12569599
- Bosch 60mm Electronic Throttle Body
- UAEFI barebones with MPXH6400 MAP sensor attached

I'm bench testing the throttle pedal and ETB but completely new to UAEFI and ETB's. I've been able to get values for PPS1, PPS2, TPS1, and TPS2 and I've checked the ETB motor operation with a 9 volt battery - the butterfly opens and closes with voltage. That said, it's still inoperable in TunerStudio and with pedal input and I get the "voltage" error that's shown in the video. So at present the ECU isn't controlling the voltage to the ETB motor which I have connected to DC1+ & DC1-. (I also tried DC2+ & DC2-). I'm hoping it's just a setting I don't understand.

I've tried searching docs and videos but haven't happened upon the information - and I AM a complete NEWB with this particular configuration.

If I can get it working, it's going on the L28ET in my 1974 Datsun 260Z which has been running on MS3X with full sequential fuel and spark.

Please confirm that car battery provides power.

Please confirm which uaefi pins are wired to that battery.

Please grab a log

AndreyB wrote: ↑

Sun Aug 17, 2025 9:53 pm

Please confirm that car battery provides power.

Please confirm which uaefi pins are wired to that battery.

Please grab a log

Yes, connected to a car battery (approx. 11.8 volts when I made the video - 13.8 later attached to charger) ECU connections:

Battery Ground: A3, A4 - verified
Ignition Switch (Battery voltage at IGN ON): A7
ECU out to Main EFI Relay: B9 (low side EFI relay coil)
EFI Relay -> battery voltage passed to: A8 - verified

Other connections to relay box = Fuel Pump Relay - B16 (hear relay come active for 4 or 5 seconds at startup, then click off)


No other battery connections

Log file (I hope...)

You seem to have proper wiring and proper power supply. I am out of ideas

Try hooking up multimeter to DC-/DC+ wires just to confirm lack of voltage activity?

Are these settings correct?

this does not look right, please 'reset settings' or something there is a button to reset to defaults

Thanks! I'll try that.

(I had a look at those pull-downs and everything listed was a "PA_ or PB_ or..." and I had no idea what any of those meant -so I left them alone. They didn't seem to correspond to any board connections. But I also don't remember changing any of those values in that dialog box so...)

Here's what should have been there. Big thanks! It's working like it should.

The 70's Z cars and the 280ZX L-Series engines have a rod and bellcrank throttle system. Ya, not even a throttle cable. It works but there's quite a bit of slop. Here's hoping this will make things better. It certainly will make the engine bay cleaner.

PC8 is Pin #8 on Connector C
PB14 is Pin #14 on Connector B
...and so forth.

Thanks Mike!