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Re: Rewiring MR2 with Syvecs TBV/IACV Question
Posted: Sat Apr 19, 2025 6:09 pm
by stevieturbo
the cam trigger posted is a valid and usable trigger. There is no reason to change it.
Everything just needs configured correctly.
Re: Rewiring MR2 with Syvecs TBV/IACV Question
Posted: Mon May 05, 2025 12:51 pm
by shmed
It's been a while, but I have been working through what else could be wrong.
Turns out that the iat was melted, presumably from one of the misfires, and reading -40degC.
I'd also forgotten to connect the knock sensor.
There was also an issue with one of the Cop connections.
All of those are now resolved and I am seeing 720 sync.
Unfortunately, it now starts, runs for a few seconds, then stops with an error 720>0 (CRITICAL CAM ERROR).
It runs ok if I slightly open the throttle so I'm thinking it might be bypass valve related.
I'll try and post the sync log later
Re: Rewiring MR2 with Syvecs TBV/IACV Question
Posted: Mon May 05, 2025 12:54 pm
by shmed
It also blew through a wastegate gasket and oil came out the hole. I've replaced the gasket but there is still smoke from the exhaust when it runs.
I've compression tested it and get a good 150psi in all four pots.
Re: Rewiring MR2 with Syvecs TBV/IACV Question
Posted: Mon May 05, 2025 3:08 pm
by shmed
Attached the sync logs.
On one the engine started then stopped.
The other is a longer run.
Re: Rewiring MR2 with Syvecs TBV/IACV Question
Posted: Mon May 05, 2025 9:02 pm
by stevieturbo
It may be getting into sync, but again, that cam waveform is rising edge. It cannot be configured as falling edge.
Re: Rewiring MR2 with Syvecs TBV/IACV Question
Posted: Mon May 05, 2025 9:21 pm
by shmed
I'll check again. I think I changed it but I've slept since then.
Re: Rewiring MR2 with Syvecs TBV/IACV Question
Posted: Mon May 05, 2025 10:05 pm
by stevieturbo
And as far as idle is concerned, if it needs more air, just give it more air.
I would tend to run the idle valve as close to closed as possible, and use the throttle blade itself to get a good solid base idle. Then the idle control only ever needs to pull the idle down.
Less work to do, less chance of stalling etc.
Re: Rewiring MR2 with Syvecs TBV/IACV Question
Posted: Sat May 10, 2025 4:44 pm
by shmed
Just checked again with a few extra gauges displayed and it looks like idle control is off. Not sure what conditions need to be met for it to come on.
Re: Rewiring MR2 with Syvecs TBV/IACV Question
Posted: Sat May 10, 2025 6:37 pm
by stevieturbo
Re: Rewiring MR2 with Syvecs TBV/IACV Question
Posted: Sat May 10, 2025 8:17 pm
by shmed
By Jove, I think I have cracked it!
I had the TBV RSO (Open) and RSC (Closed) wired backwards...
I rigged up a spare connector to the TBV and put 12V down the open channel and the car ran fine. Stuck the ECU connector back in, and it kept cutting out.
Traced the wires, and found them to be backwards. Revered this, and it now idles!!!
Next thing is to wire the RSC back in as it is currently "floating".
Looks like the stock MR2 TBV sits at 50% when neither RSC or RSO are powered, so the ECU has no way of actually closing the valve. I think this can be achieved using TBV2, but am happy to leave it for now.