Very poor mpg 2zz

[JB21]

Corolla 2ZZ ECU over fuels like a pig, mine was doing exactly the same with LTFT at -20. I tried everything from injectors, to intake but nothing worked. In the end I got an Apexi PFC and tune that sorted the over the fueling, car runs like a dream now with AFR's spot on.

[Carolyn]

It's still special, isn't it?

[MrChris]

Corolla 2ZZ ECU over fuels like a pig, mine was doing exactly the same with LTFT at -20. I tried everything from injectors, to intake but nothing worked. In the end I got an Apexi PFC and tune that sorted the over the fueling, car runs like a dream now with AFR's spot on.

That's interesting but I don't quite understand why the Corolla ECU specifically would cause overfuelling? Also a brief search indicates that getting an Apexi PFC and a  tune is not exactly a cost-effective solution..? 

[Carolyn]

Brilliant thanks @jvanzyl - I've noticed my injectors have an o ring and one seal. Whereas the kits online I've seen have 3 seals per injector, so I'm confused.

O ring at the top and a thicker rubber 'donut' at the bottom.  The bottom one keeps air out and the top one prevents fuel leaks.

[MrChris]

O ring at the top and a thicker rubber 'donut' at the bottom.  The bottom one keeps air out and the top one prevents fuel leaks.

Yeah so that's 2 "seals", but the kits appear to have a third seal per injector, that's the one I'm confused about.

[Carolyn]

Yeah so that's 2 "seals", but the kits appear to have a third seal per injector, that's the one I'm confused about.

That's all there are.  Two.

[Carolyn]

I've had a peek on the old interweb.. The other bits aren't seals, they are replacement fittings for each end of the injector.  One is a new bottom cap and the other is a replacement filter.  I've never messed with either of those.

[MrChris]

@JB21 Another one on the ECU side of things... is it possible to use a Celica or other ECU that's not a Corolla ECU?

[tricky1138]

@JB21 Another one on the ECU side of things... is it possible to use a Celica or other ECU that's not a Corolla ECU?

I'm sure I heard ages ago that you shouldnt use the Corolla ECU and to use a Celica one when doing the 2ZZ swap so it's definitely possible.

No idea why, just know when Mulaz did his swap using a Corolla engine/car he had to use a Celica ECU.

[shnazzle]

I'm sure I heard ages ago that you shouldnt use the Corolla ECU and to use a Celica one when doing the 2ZZ swap so it's definitely possible.

No idea why, just know when Mulaz did his swap using a Corolla engine/car he had to use a Celica ECU.

Similarly I recall vaguely that there's a particular Corolla ECU that does work well and has higher lift points etc.
But it wouldn't run the dash so you needed to "piggyback" it on the stock ECU or have the magic box of tricks.

Celica is the easiest

[MrChris]

@tricky1138 @shnazzle So I'm working and have limited time to look at this but initial reading suggests that I need a JDM (no OBD2) or US ECU due to issues with the immobiliser or is that not an issue and I can get around it easily? My initial thought was I can just buy the appropriate Celica ECU from this country and as long as the pin-outs are correct on the harness I should be okay?

[shnazzle]

@tricky1138 @shnazzle So I'm working and have limited time to look at this but initial reading suggests that I need a JDM (no OBD2) or US ECU due to issues with the immobiliser or is that not an issue and I can get around it easily? My initial thought was I can just buy the appropriate Celica ECU from this country and as long as the pin-outs are correct on the harness I should be okay?

If you don't have an immobiliser currently they yes you'd want the JDM or US.
Also the JDM has the bonus of no post-cat 02 sensor. Makes things easier.

Pinouts I THINK are slightly different on Corolla. So if you have a Corolla ECU now it might not be plug/play.
I'd have to do some digging. I wrote a 2zz conversion guide on here many many moons ago and I think I may have had some ECU/wiring infon in there

[MrChris]

If you don't have an immobiliser currently they yes you'd want the JDM or US.
Also the JDM has the bonus of no post-cat 02 sensor. Makes things easier.

Pinouts I THINK are slightly different on Corolla. So if you have a Corolla ECU now it might not be plug/play.
I'd have to do some digging. I wrote a 2zz conversion guide on here many many moons ago and I think I may have had some ECU/wiring infon in there

Took an early lunch and actually checked the ECU I have in there. I think it's actually a Celica one: 89666-20150... so that makes life much simpler!!


I've got an exhaust manifold gasket on the way and hopefully the seals from @Carolyn  and potentially injectors from @KRAMSNEHPETS may see me right... will swap the O2 sensors too just to be sure.

[tricky1138]

Celica ECU still has an immobiliser but if the car is starting then it must be working.

Usually the key barrel has an immobiliser ring which links to the ECU and the key fob to disable it. On a swap the ring is usually just put somewhere near the key barrel so the key can still read it.

But as I said, if its starting then the immobiliser is working / allowing the car to start.

Hopefully Shnazzle will be along soon with more useful help.

[shnazzle]

Celica ECU still has an immobiliser but if the car is starting then it must be working.

Usually the key barrel has an immobiliser ring which links to the ECU and the key fob to disable it. On a swap the ring is usually just put somewhere near the key barrel so the key can still read it.

But as I said, if its starting then the immobiliser is working / allowing the car to start.

Hopefully Shnazzle will be along soon with more useful help.

Shnazzle will not. Shnazzle has been out of the game too long LOL

[Alex Knight]

I'm sure I heard ages ago that you shouldnt use the Corolla ECU and to use a Celica one when doing the 2ZZ swap so it's definitely possible.

No idea why, just know when Mulaz did his swap using a Corolla engine/car he had to use a Celica ECU.

Corolla ECU will run the engine, but not the dash. That's the reason.

Best ECU to get is an early Celica 190 (not T-Sport) if you want to retain the immobiliser.

If you're not bothered (I would be) about the immobiliser, go for a JDM Celica ECU.

[KRAMSNEHPETS]

Posted today. Cost will be a bacon sandwich if you make Blyton park 5th Oct!

[MrChris]

Posted today. Cost will be a bacon sandwich if you make Blyton park 5th Oct!

If I make it there, how about some tuition (not from me, I'll pay for a session  )?

Edit: Bugger it's sold out Might get on the 9th November. Will fix the 2 first!

[MrChris]

Popped out this morning to see if I could get the exhaust manifold gasket installed and almost got there. I stopped because looking at the picture attached, I'm sure there should be 2 studs and not one. I.e. one on the right and one on the left. If this is right I need to order one before continuing, would anyone know the specs and torque values for these? Thanks.

Edit: found this https://www.eliseparts.com/shop/exhaust-system-1/toyota-2zz-manifold-stud-and-nut/

Edit 2: I'm getting ahead of myself this morning by posting this. Forgot I had a repair manual in the paperwork I got with the car which was packed well away... anyway, found a diagram that answers my question that there should indeed be two nuts with studs, so I will order up two new sets just in case the existing one is stretched (though unlikely)...

[MrChris]

@Carolyn and @KRAMSNEHPETS

O-rings and injectors have arrived today. Again, thank you very much for helping me out. I've got a wedding to go to over the weekend but hoping I get some time after to install and will provide an update here. Hopefully with the new gasket and studs for the exhaust manifold, the items you've provided and an ECU reset I should be back to normal.

[KRAMSNEHPETS]

Just for reference. Mallory Park today in my 2ZZ, 104 laps. 126 miles , 49 litres just under 12 MPG!!