Rewiring MR2 with Syvecs TBV/IACV Question

stevieturbo
Posts: 1392
Joined: Sun Dec 07, 2008 2:04 pm

Re: Rewiring MR2 with Syvecs TBV/IACV Question

Post by stevieturbo »

the cam trigger posted is a valid and usable trigger. There is no reason to change it.

Everything just needs configured correctly.
shmed
Posts: 67
Joined: Fri Jan 10, 2014 11:05 am

Re: Rewiring MR2 with Syvecs TBV/IACV Question

Post 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
shmed
Posts: 67
Joined: Fri Jan 10, 2014 11:05 am

Re: Rewiring MR2 with Syvecs TBV/IACV Question

Post 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.
shmed
Posts: 67
Joined: Fri Jan 10, 2014 11:05 am

Re: Rewiring MR2 with Syvecs TBV/IACV Question

Post by shmed »

Attached the sync logs.

On one the engine started then stopped.

The other is a longer run.
Attachments
20250505_startstop.txt
(256.4 KiB) Downloaded 39 times
20250505_longerrun.txt
(250.96 KiB) Downloaded 33 times
stevieturbo
Posts: 1392
Joined: Sun Dec 07, 2008 2:04 pm

Re: Rewiring MR2 with Syvecs TBV/IACV Question

Post by stevieturbo »

It may be getting into sync, but again, that cam waveform is rising edge. It cannot be configured as falling edge.
shmed
Posts: 67
Joined: Fri Jan 10, 2014 11:05 am

Re: Rewiring MR2 with Syvecs TBV/IACV Question

Post by shmed »

I'll check again. I think I changed it but I've slept since then.
stevieturbo
Posts: 1392
Joined: Sun Dec 07, 2008 2:04 pm

Re: Rewiring MR2 with Syvecs TBV/IACV Question

Post 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.
shmed
Posts: 67
Joined: Fri Jan 10, 2014 11:05 am

Re: Rewiring MR2 with Syvecs TBV/IACV Question

Post 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.
shmed
Posts: 67
Joined: Fri Jan 10, 2014 11:05 am

Re: Rewiring MR2 with Syvecs TBV/IACV Question

Post 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.
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