Ultimate fuel cut at 2500rpm
 

Hello and happy holidays,

we are working on a 90 1.6 JRSC Miata with AC and Tempomat.
Car runs fine without Ultimate.
Plugging the Ultimate in, pushing the throttle,
car revs to ~2500rpm then cuts Inj duty cycle to zero.
Falling to ~1800rpm, same game.

Datalog is not indicating any relevant changes in any engine data,
only the fuelcut is existant.

Any ideas?

Falk

In the logs, is the InjInput being cut, or only the InjOutput?

Hello Joe,
the INJ input is zero above ~2500rpm.
Nutz forum says TPS wire symptom.

We use the greddy pressure senor to simulate
TPS signal for autotune.

Falk

If the INJ input (from the ECU to the EMU) is zero, then it isn't the TPS. It means the ECU is unhappy.

Is the EMU connected to the CMP / CKP lines? If so, disconnect. It should only be connected to the RPM (tach) wire.

What other connections is the EMU involved in that could be upsetting the stock ECU?

Hello,
I agree with Joe, the ECU is unhappy.
What is the CMP/CKP lines?
Its a basic EMU setup, greddy boost sensor on option port 1
Zeitronix WBO2 on Option port 2.
Boost Signal line sliced to feed EMU TPS input for Autotune.

here is the log:
http://www.alumex.de/MX5/tom3.lg2

On the car appeared another failure before,
after ignition on, the main Voltage on the ECU dropped to 10.5V only.
We think it was the Zeitronix, probably the sensor heat which caused the drop.
A new direct feed line solved that.
First time this happened with a Zeitronox ZT-2.

Falk

CMP and CKP = Cam Pulse and Crank Pulse- the two signals from the CAS. At the ECU, they are the Yellow/Blue wire at 2G and the White wire at 2E.

Without also having an EM2 file, your log is coming up as gibberish on my system.

CAS+CAM disconnected
here the EM2 file, software version 2.16
http://www.alumex.de/MX5/tom3.EM2

Falk

seems the problem is solved.

The TPS wire was connected with the Zeitronix ZT-2 WBO2
TPS input line. For any reason this gave a wrong signal.

We experienced the ZT-2 as a though WBO2 system,
lets see why this wrong signal came up.

thanks for help anyway

Falk

next TPS fun
 

Ok, here we go, this Miata dont like the Ultimate.
We have installed a few meanwhile, this car
surprises again and again.

To use the autotune function, we simulate the TPS
with the map sensor signal.
NOTHING else is connected with this, only map signal
spliced and connected to the EMU TPS input.
Depending on the voltage we put in the Throttle settings,
the car starts or not.
For example at 0.5V min - 1.5V max, the car dont start.
at 0.8V min - 2V max the car starts fine.

How can the simulated throttle settings affect the ECU
INJ duty cycle, again the logged INJ input duty cyle??
*sure TPS is not used in the drop down menus,
neither in the AF-target affected map menu.

Falk