Zage Turbo Kit Install - Toyota Yaris

[06YarisRS]

Originally Posted by Focus_Sh1ft

Hey YW! Been quite awhile.

I wanted to share some FIC knowledge, as I recently ran into the dreaded stalling while idling/stalling while coming to a stop/stutter on rapid acceleration changes. What ultimately worked for me: change the cam and crank wires to tap only. So, MAGI+ and MAGI- are taps, and MAGO+ and MAGO- are unused. You'll still get RPM readings, however you'll lose ignition control (which I'm guessing isn't used for most applications anyway). Read on for more details -

Some background: I was one of the first to install the Zage turbo kit, way back in 2010. I tuned on the fic using open loop (both o2 sensors pulled) and ran that setup daily for 7 years before finally retiring the Yaris from daily duties. I had two issues with the fic during that time: the onboard pressure sensor failed (I ended up hooking up an external pressure sensor to the maf input of the fic) and the eeprom would no longer hold the tune when powered down (not a big deal, just rewired the fic to be connected to a +12v line rather than acc).

Late last year, I converted the Yaris from AT to MT. The whole thing went pretty well aside from the aforementioned issues starting. I did a ton of rework while I had the engine apart, including running grounds into the cabin for a killswitch and completely overhauling the vacuum setup to use a junction block (which was previously tees with tees with tees; I learned a lot these last 10 years, haha) and a recirculating bov. Naturally, I thought the issues were caused by something I had done. This led me down some rabbit holes...

First up was P0606. On first start, this code was set immediately. With the AT (which used an 08 ECU btw), I only ever had P0037. This manual ECU was an 07, so I thought different firmware with potentially slightly different error handling logic means potentially a different (but related) code could get set instead. This seemed reasonable given P0606 is generally either o2/throttle/ecu. Putting the o2 sensors back in with the fic bypassed didn't solve it. Nor did replacing the ecu with another 07. All readings from the throttle were within range. I still have this code - however at this point, I have to conclude this was not related to my problems at all.

My next thought was this had to be a vacuum leak. I had no evidence for this, and in fact, I was pulling perfect vacuum during idle. During vacuum tests, I noticed my brake booster was leaking during braking. I was certain this was the problem, as the car would stumble and recover on braking when running a bypassed fic with o2 sensors in, but would pretty consistently stall with the fic in and no o2 sensors. My thought was closed loop fueling was able to compensate for this conditional vacuum leak.

Replacing the booster didn't do it. I fumbled for awhile before remembering many people having trouble getting the fic working. I was fortunate to not be one of those at the time, but not only did I now have an MT ecu (I don't think anyone else turboed an AT at the time), I also had a different model year. Perhaps it was the interplay between the fic and new ecu? I zeroed out the maps and put the o2 sensors back in. The engine warmed up and began stumbling. Sure enough.

I tried all sorts of configurations in the fic, including trying all the firmwares, with no luck. After some reading, I was certain the resistor mod was going to do it, but nope. Still, I was now convinced this was my issue - the fic doing incorrect things with the cam/crank signals. It seemed if the fic wasn't intercepting signals, it likely wouldn't be able to manipulate them. There was also the concern if a tap would be enough to read rpm, as that was tuned against. I gave it a shot and fired it up - perfect idle. Took the car out and did some hard pulls - completely smooth. Finally.

It's hard to believe I've had this car for over 14 years... So much living has happened during that time. One thing is for sure; I wish I hadn't waited 14 years to swap in a manual. The Yaris was fun before, but now it's an absolute riot.

I'm sure I've said it before, but it's obviously been awhile so I'll say it again - thank you. This community got me to where I am today.

See you all in another 10 years. ;)

Interesting reading! Looking forward to spring when I can resume work on my car. I have been considering an alternative to the FIC for one reason - long hot starts. If it's cool out or even really freezing, the car starts immediately on a key turn. If the engine is warm or it's a hot day, it cranks and cranks before it will start. I have adjusted the fuel table in the startup rpm range, no luck. I initially thought it had to do with overfueling, but now wonder if it's related to crank position, though I don't know what that would have to do with termperature. Otherwise the car runs great. I didn't wire in my cams at all.