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Re: Rewiring MR2 with Syvecs TBV/IACV Question
Posted: Wed Apr 16, 2025 12:08 am
by shmed
The car has a crank sensor, so I reckon it must've used the single tooth on the cam. I'm going to go with the green wire and see how it goes.
Not sure what lambda was on it before, but I think it was a 4 wire.
As for the idle, I was looking at the original scal config, and there was only a single output for iacv. Looking at the latest scal, there now seems to be two. Iacv a and iacv b. Hopefully that will solve my issue.
Thanks for getting back to me though. Will be trying the engine out in the next few days. It's not run for ten years..
Re: Rewiring MR2 with Syvecs TBV/IACV Question
Posted: Wed Apr 16, 2025 7:17 am
by stevieturbo
It would be odd for anyone to just use a narrowband sensor. The S6 is intended for the NTK sensor
How was the ecu configured before ? Have you any datalogs where you can see lambda ?
Re: Rewiring MR2 with Syvecs TBV/IACV Question
Posted: Wed Apr 16, 2025 9:27 am
by shmed
No data logs, but I do have the original Syvecs config. I'm not at home today so can't check what the old lambda was, but will check later.
It was configured like this:
Sensors | Lambda | Lambda Sensor 1
Input Configuration = 5V
Default V High = 5V
Default V Low = 0V
Default Sensor Reading = 1.250
Filter Constant = 98.00
Failure Rate = 100
Recovery Rate = 20
Sensor Type: Wideband UEGO
Linearisation:
The new config (having switched the sensor type from 5V to UEGO) looks remarkably similar.
Re: Rewiring MR2 with Syvecs TBV/IACV Question
Posted: Wed Apr 16, 2025 7:04 pm
by shmed
So, wired red & green from cam pos to ecu, added gauges to SCal for AN01 (CAM) and AN02 (Crank).
Cranked the engine and this was the output:
Do you think that looks right? I think it does; reads lots of change on the crank, and one change per cycle on the cam.
Re: Rewiring MR2 with Syvecs TBV/IACV Question
Posted: Wed Apr 16, 2025 8:26 pm
by stevieturbo
Save the synclog, it will give a much clearer picture than that, which isn't very clear at all. But there are signals there.
As for the old lambda, what was the input wired to ? There is a dedicated input for the NTK sensor ( dedicated for all wires aside from the heater ground which is a generic ecu output )
Wiring instructions covers this anyway
https://www.youtube.com/watch?v=xQcv9YK-DQ0
Re: Rewiring MR2 with Syvecs TBV/IACV Question
Posted: Wed Apr 16, 2025 8:48 pm
by shmed
I'll have a look at doing that at the weekend. Any tips on what to do, or is it relatively obvious?
Re: Rewiring MR2 with Syvecs TBV/IACV Question
Posted: Wed Apr 16, 2025 8:55 pm
by shmed
Just checked the old lambda and it has four wires, two black a white and a blue. Google suggests that the two black are heater wires.
The old config didn't use the connectors that are recommended for the ntk sensor as I've had to reconfigure it to match the new sensor.
Re: Rewiring MR2 with Syvecs TBV/IACV Question
Posted: Wed Apr 16, 2025 9:39 pm
by stevieturbo
shmed wrote: ↑Wed Apr 16, 2025 8:48 pm
I'll have a look at doing that at the weekend. Any tips on what to do, or is it relatively obvious?
tips on what to do with what ?
Re: Rewiring MR2 with Syvecs TBV/IACV Question
Posted: Wed Apr 16, 2025 10:00 pm
by shmed
Saving the sync log. I'm guessing that it is really simple

Re: Rewiring MR2 with Syvecs TBV/IACV Question
Posted: Wed Apr 16, 2025 10:29 pm
by stevieturbo
I posted the youtube video for the synclogs etc.