DIY - 1.8L 1ZZ-FE TB Connector Chip Swap

[Saggio]

Thanks Gideon! I think I'll be getting one and trying this out.

[yarstar]

I strongly recommend this Saggio. I really have felt a difference with this mod. I have taken the TB back off and installed the original (trying to fix the CEL) and couldn't stand the power loss so I re-installed the 1.8L TB. CEL comes and goes, but who cares.

[blacksandiegovitz]

Originally Posted by yarstar

I strongly recommend this Saggio. I really have felt a difference with this mod. I have taken the TB back off and installed the original (trying to fix the CEL) and couldn't stand the power loss so I re-installed the 1.8L TB. CEL comes and goes, but who cares.

I had planned on picking one of those tb up this weekend from the same ebay guy , and your statement just made me 100% on getting one

[yarstar]

Just like Gideon, I even like the high rev cold idle. My car sounds like it has a turbine engine when it fires up. The idle goes down once the cold light goes off. High idle only for about a minute.

[blacksandiegovitz]

Originally Posted by yarstar

Just like Gideon, I even like the high rev cold idle. My car sounds like it has a turbine engine when it fires up. The idle goes down once the cold light goes off. High idle only for about a minute.

Before the yaris , I owned nothing but beastly dsm's and mk3 turbos so i'm use to loud cars with rough idle . Imo the yaris was wayyyyy to quite when I first got it . I'm sporting aem w/fujita filter , megan header, nitto mid, hks axle back , nst 10% ud pulley running on 91 and i'm very surprised at how "peppy" this little 1.5 yaris has become . Modds planned are the Tb swap , coolent bypass , tb spacer (for S's and G's and I'm gonna do before and after dyno test for proof good/bad) and my friend is starting on a 1-off long tube header for me(similar to Richard's design)

[jkuchta]

Hey everyone:

I did this swap this last Sunday...and man what a differeance!

First off I installed the 1ZZ TB stock (no idle screw adjustment or chip swap). Cold idle was high (around 3K) and fluctuated, like everyone has mentioned, though my warm idle was around 850-900rpm, with a pretty bitchin' roughness (think bigger cam). There were definate problems though.

1) CEL: came on intermittantly with P0171 (iirc) lean condition, especially while transitioning from idle to part throttle, though once cleared, this CEL would not come back while driving or coming back to a stop, which makes me want to rule out any sort of air leak.

2) Throttle response was lacking, and pretty disconnected..i.e. while shifting the engine would over-rev 500-1000rpm, and the car seemed to lack any real grunt anywhere in the powerband. I have a scangauge, and could see I was getting full throttle operation.

3) When the car went into DFCO it would feel like I had just released the 'chuts! With the OEM TB DFCO is almost inperceptable, but with the unadjusted 1ZZ TB it was pretty uncomfortable feeling.

4) Heel-toe downshifting was pretty much impossible as well due to lack of fine rev control, and a wierd over-rev/under-rev (the car stalled itself twice) on deceleration.

These symptoms were consistant over more than 3 hours of driving.



On Monday afternoon, I removed the 1ZZ TB and swapped out the chip with the OEM 1NZ chip. I did this without disconnecting the battery, as I wanted to see how big a difference this swap would make, all other things being equal.

BIG DIFFERENCE!

1) High Cold idle lasts about half as long. Also, there is no ocillation. The rpms just go straight to 2500-2700, and then slowly taper back down.

2) The idle is also much more stable (like stock), with no (albeit cool) roughness.



Now I got to work setting the correct idle speed. For some reason, the epoxy over the idle set screw on my 1ZZ TB came off nice and easy, an in one piece. After a few minutes idleing, the engine settled to about 1K rpm, which set off a CEL (I think P0220 iirc(TB stuck open)). I adjusted the screw to the point of killing the engine (which triggered another CEL (P0505...bad idle)). I then screwed the idle set screw back in about half way, which when the engine was turned back on, gave me an idle of about 850 rpm. I then shut the engine back off and adjusted the screw back out about a turn, which (when the engine was turned back on) gave me a nice stable (and smooth) 720-750rpm.

Based on the manual, this is as high as you can go without running the risk of getting a "bad idle" CEL. This idle rpm also makes leaving stoplights a little better in that the engine doesn't bog quite as much.



A note on setting the idle:

Adjustments should be made with the engine and ignition off, as doing the adjustment with the engine running will only cause the ECU to compensate to maintain the idle speed, almost regardless of the idle set screw position (took me 10 min. to figure that out).


Driving impressions:


1) Throttle response is better than stock, and the car pulls like a motha' (well....way more than with the stock TB) above 2200 rpms.

2) Heel-toe downshifting is better than stock (rpms come up a little faster, and with a little more "control" (i.e. a little tap gives a few hundred rpm (great for the 5th-4th shift), and a bigger dab gives about 1000 rpm (great for 4th-3rd, and 3rd-2nd shifts).

Once the idle was set there have been no CELs of any kind, and the car is a riot to drive!

As far as I'm concerned...this is a must-do mod for anyone with the stomach to do the chip swap (drilling out that first rivet is mentally the hard part), though the idle adjustment is pretty much a requirment to make this thing feel right.




A big THANK YOU to T-sport for the diy (and having the nuts to do this in the first place)!




Side note:

I also did the TB coolent bypass. My other mods are as follows : Simota Carbon SRI (the big box), WR header, Thermal axle-back, and nology hotwires, running Shell V-Power and Motul 300V 5W-30.

[blacksandiegovitz]

Originally Posted by jkuchta

Hey everyone:

I did this swap this last Sunday...and man what a differeance!

First off I installed the 1ZZ TB stock (no idle screw adjustment or chip swap). Cold idle was high (around 3K) and fluctuated, like everyone has mentioned, though my warm idle was around 850-900rpm, with a pretty bitchin' roughness (think bigger cam). There were definate problems though.

1) CEL: came on intermittantly with P0171 (iirc) lean condition, especially while transitioning from idle to part throttle, though once cleared, this CEL would not come back while driving or coming back to a stop, which makes me want to rule out any sort of air leak.

2) Throttle response was lacking, and pretty disconnected..i.e. while shifting the engine would over-rev 500-1000rpm, and the car seemed to lack any real grunt anywhere in the powerband. I have a scangauge, and could see I was getting full throttle operation.

3) When the car went into DFCO it would feel like I had just released the 'chuts! With the OEM TB DFCO is almost inperceptable, but with the unadjusted 1ZZ TB it was pretty uncomfortable feeling.

4) Heel-toe downshifting was pretty much impossible as well due to lack of fine rev control, and a wierd over-rev/under-rev (the car stalled itself twice) on deceleration.

These symptoms were consistant over more than 3 hours of driving.



On Monday afternoon, I removed the 1ZZ TB and swapped out the chip with the OEM 1NZ chip. I did this without disconnecting the battery, as I wanted to see how big a difference this swap would make, all other things being equal.

BIG DIFFERENCE!

1) High Cold idle lasts about half as long. Also, there is no ocillation. The rpms just go straight to 2500-2700, and then slowly taper back down.

2) The idle is also much more stable (like stock), with no (albeit cool) roughness.



Now I got to work setting the correct idle speed. For some reason, the epoxy over the idle set screw on my 1ZZ TB came off nice and easy, an in one piece. After a few minutes idleing, the engine settled to about 1K rpm, which set off a CEL (I think P0220 iirc(TB stuck open)). I adjusted the screw to the point of killing the engine (which triggered another CEL (P0505...bad idle)). I then screwed the idle set screw back in about half way, which when the engine was turned back on, gave me an idle of about 850 rpm. I then shut the engine back off and adjusted the screw back out about a turn, which (when the engine was turned back on) gave me a nice stable (and smooth) 720-750rpm.

Based on the manual, this is as high as you can go without running the risk of getting a "bad idle" CEL. This idle rpm also makes leaving stoplights a little better in that the engine doesn't bog quite as much.



A note on setting the idle:

Adjustments should be made with the engine and ignition off, as doing the adjustment with the engine running will only cause the ECU to compensate to maintain the idle speed, almost regardless of the idle set screw position (took me 10 min. to figure that out).


Driving impressions:


1) Throttle response is better than stock, and the car pulls like a motha' (well....way more than with the stock TB) above 2200 rpms.

2) Heel-toe downshifting is better than stock (rpms come up a little faster, and with a little more "control" (i.e. a little tap gives a few hundred rpm (great for the 5th-4th shift), and a bigger dab gives about 1000 rpm (great for 4th-3rd, and 3rd-2nd shifts).

Once the idle was set there have been no CELs of any kind, and the car is a riot to drive!

As far as I'm concerned...this is a must-do mod for anyone with the stomach to do the chip swap (drilling out that first rivet is mentally the hard part), though the idle adjustment is pretty much a requirment to make this thing feel right.




A big THANK YOU to T-sport for the diy (and having the nuts to do this in the first place)!




Side note:

I also did the TB coolent bypass. My other mods are as follows : Simota Carbon SRI (the big box), WR header, Thermal axle-back, and nology hotwires, running Shell V-Power and Motul 300V 5W-30.

^^^ Very good write up , now i'm really ready to do this modd ! What did you need for the Tb coolent bypass? Just checking so I can buy the right parts the first time .

[jkuchta]

Double barb 3/4" union (Home depot). I reused the OEM hose clamps (they are in pretty much A1 shape).





Kustom, I got the TB from TheBarber, but eBay is also a good source.

[blacksandiegovitz]

Originally Posted by jkuchta

Double barb 3/4" union (Home depot). I reused the OEM hose clamps (they are in pretty much A1 shape).





Kustom, I got the TB from TheBarber, but eBay is also a good source.

Thanks man I bought mk3 supra parts from the ebay seller in the link in post #19 and he was legit , I plan on getting the tb from him too .

[Nexus1155]

jkuchta that was a sick review, how many miles have you put on the TB since the chip swap? If its not many i might want to wait a bit to grab one. But it seems like its spot on!

[dallas]

Great write up Bravo, if you live in a cold climate don't do the coolant bypass, in the winter it will ice, great mod for summer as it reduces intake temps.

[hatchbackkid82]

Ok so looks like i'm part of the CEL club. Installed it w/o a hitch except for the brass fittinh i had to buy, didn't want to bypass the coolant line through th TB. Started the car up, and had the high idle for about a min. or so. Oscillated for a few seconds before it finally started to taper off and idle normal, slightly higher idle than stock. Drove the car around, has great midrange and top end. After driving it for about 2-3mins i got a CEL. Disconnected the battery for a few mins CEL was off again after a few miles came right back on. I've swapped the chip over from the 1NZ TB. I hate CEL Good mod for the money just hate seeing that CEL light on. Also the car does feel like when shifting it's holding on to the revs, instead of the rpm's dropping it feels like it revs at whatever rpm you were at before you shifted. And when coasting in gear maybe it's just me but it seems real jerky at time. It will hit a certain rpm where it does that

[hatchbackkid82]

Anyone know how to get that expoxy off to adjust the idle control?

[Nexus1155]

i dont think anything makes epoxy soluble, the only way to do it is either burn it off, or pick it out

[Saggio]

Freeze Spray or pick it out.

[jkuchta]

The only experiance I have is with the Corolla TB, so that's the only one that I can say for sure fits.

Dallas,

The TB can't ice up, as there is no fuel passing through the TB. To get normal intake air to ice up you'd need to run it through a really small venturi to get the pressure low enough.


Hatchbackkid, do you know what the DTC associated with the CEL is? Sounds like you have an air leak. Don't forget that the silicone sealent has to sit for a few hours to harden enough to resist the vacuum at idle.

[dallas]

I thought that is the only reason why they run hot coolant lines into the TB, in our cold climate if you bypass it you will have issues around zero, with rought running etc everyone around here calls it icing, do you know whats actually happening! I agree for ulimate performance you don't want it hot as a cooler air is more dense,

Originally Posted by jkuchta

The only experiance I have is with the Corolla TB, so that's the only one that I can say for sure fits.

Dallas,

The TB can't ice up, as there is no fuel passing through the TB. To get normal intake air to ice up you'd need to run it through a really small venturi to get the pressure low enough.


Hatchbackkid, do you know what the DTC associated with the CEL is? Sounds like you have an air leak. Don't forget that the silicone sealent has to sit for a few hours to harden enough to resist the vacuum at idle.

[jkuchta]

As far as I can tell, the TB is heated to give better fuel economy. Why a cold charge would cause those problems is beyond me.

I've flown injected piston aircraft is sub-zero conditions and they just seem to run stronger!