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

[MGargano]

Originally Posted by jkuchta

What codes are showing up?

Just saying you have a CEL is kind of worthless unless we know what the code is. It could be just a case of needing to adjust the idle set screw, or a number of other things.

P0505- Idle Malfunction

[jkuchta]

Have you adjusted the idle screw? If you've turned the screw out too far you could get this code...try turning the screw in one or two turns (with the car off). This should fix the problem.

If you haven't adjusted the idle set screw, turn it counter-clockwise 1.5 turns (with the engine off), and see what happens.

[MGargano]

Originally Posted by jkuchta

Have you adjusted the idle screw? If you've turned the screw out too far you could get this code...try turning the screw in one or two turns (with the car off). This should fix the problem.

If you haven't adjusted the idle set screw, turn it counter-clockwise 1.5 turns (with the engine off), and see what happens.

I haven't touched the idle screw at all. The thing was working perfectly for over a month, right up until I disconnected the battery. I'm not going through this every time I disconnect the battery... plus, even when it's working perfectly, the high idle is now quite loud with the exhaust I have. I'm 99% I'm switching back to the stocker today.

[jkuchta]

Originally Posted by MGargano

I haven't touched the idle screw at all. The thing was working perfectly for over a month, right up until I disconnected the battery. I'm not going through this every time I disconnect the battery... plus, even when it's working perfectly, the high idle is now quite loud with the exhaust I have. I'm 99% I'm switching back to the stocker today.

If you turn the idle set screw out about a turn and a half, all of your problems will go away.

When you leave the screw is the "corolla" position, the yaris ECU adjusts the idle fuel to get a stable idle. This takes time, as the ECU needs to make some pretty big changes. When you adjust the idle set screw to the correct position, the ECU doesn't have to work nearly as hard to get a normal idle, so the ECU doesn't freak out.

The idle rpm fluctuations are a result of the ECU hunting for the right fueling to maintain a steady 600-700 rpm idle in the face of way too much air going through an unadjusted corolla TB.

The P0505 code is the ECU saying..."WTF!!...Why can't I idle at the fuel trims I'm programmed with...something must be wrong!!"

[MGargano]

Originally Posted by jkuchta

If you turn the idle set screw out about a turn and a half, all of your problems will go away.

So I should turn it all the way in, then back out 1.5 turns? If not, what's the 'correct' procedure for adjusting the idle screw?

[tk-421]

Originally Posted by MGargano

So I should turn it all the way in, then back out 1.5 turns? If not, what's the 'correct' procedure for adjusting the idle screw?

1. Turn engine off
2. Adjust the screw to your liking
3. Turn engine on and test for oscillation and high idle
4. If you need to modify the value, go to step 1
5. If you're satisfied with the setting, throw some epoxy in there and let dry (optional, but recommended)

FYI, I've read that it's better not to try adjusting the screw with the engine on, or else the ECU might need to be rebooted one last time to reset the values.

I had no idea which direction to turn to or anything like that... All I did was turn clockwise until I found the best setting after the second try. I guess I got lucky, because the damn screw got stripped at a very decent setting, so I didn't need to do any tweaking afterwards.

I also let the gasket maker do its thing for at least 4 hours IIRC, with the battery disconnected the whole time. I also did the coolant bypass, but didn't need to burp it afterwards.

No big oscillations, no CELs, and a pretty decent 2.5K idle... could've been a bit better, but I'm not complaining.

[jkuchta]

Originally Posted by MGargano

So I should turn it all the way in, then back out 1.5 turns? If not, what's the 'correct' procedure for adjusting the idle screw?

No...turn it 1.5 turns counter-clockwise from the stock Corolla position (where it is when you first get the epoxy off).

[Yoda]

any one has a DYI on how to install the TB? I am looking through tha manuall and drawing a blank. Do i need anything special?

[AlexNet0]

Originally Posted by Yoda

any one has a DYI on how to install the TB? I am looking through tha manuall and drawing a blank. Do i need anything special?

If you search, you will find it. there have been like 3

[Yoda]

Originally Posted by AlexNet0

If you search, you will find it. there have been like 3

thx it wasnt too hard so i didnt need the diy. Didnt do the chip swap gonna see what other means there are to eliminate the cel if i get any.

[jkuchta]

Originally Posted by Yoda

thx it wasnt too hard so i didnt need the diy. Didnt do the chip swap gonna see what other means there are to eliminate the cel if i get any.

If you adjust the idle set screw you might be ok.

[Yoda]

Originally Posted by jkuchta

If you adjust the idle set screw you might be ok.

adjust it to were? sry total noob at this. dont even kno where the darn thing is

[AlexNet0]

Originally Posted by Yoda

thx it wasnt too hard so i didnt need the diy. Didnt do the chip swap gonna see what other means there are to eliminate the cel if i get any.

Did you get the oscillation? thats what the chip swap was originally indended to fix

[tk-421]

The cold start sounds normal to me. In my case it's always @ 2.5K
It shouldn't settle @1.1K though... That sounds high to me when idling.
The CEL thing is hit/miss... Some ppl get it, some ppl don't.

[Yoda]

Originally Posted by tk-421

The cold start sounds normal to me. In my case it's always @ 2.5K
It shouldn't settle @1.1K though... That sounds high to me when idling.
The CEL thing is hit/miss... Some ppl get it, some ppl don't.

yea but something is up with the throttle. i gonna try it again once it resets. I think i might have to turn the screw until the idle get down to normal. Little small turns lol.
I hope i didnt get a defective one.

[jkuchta]

Turn the idle screw 1.5 turns counter-clockwise. Also, if you used any gasket maker, you need to not run the car for a few hours to let that stuff cure, or else the idle vacuum will suck the stuff into the intake manifold...which will give you really erratic running and a CEL.

[Yoda]

well its morning gonna try again that idle screw is hard to turn.

[Yoda]

ffs its stripped the fing screw!!!