Partner Caroline has a 2zz comp bought as a runner approx 2 years ago. There were a few issues needing sorted including the Compressor clutch failing, & the engine mounting requiring modifying. IACV bother. Coilpacks replaced.
But now it runs consistently albeit with the following issue.
It's got a stutter/misfire that starts at around 3800 revs. In 2nd gear with heavy throttle it stutters briefly, & then revs through it up past 5k no problem. In 3rd, it does the same, but the stutter phase takes longer to get through. Once through it again accelerates cleanly.
I wasn't able to get it on a quick enough road to check 4th gear, but Caroline says that sometimes it will not rev through the stuttering rev-phase in 4th.
Could try a coupe of bottles of octane booster, see if that does the trick? Back when we had the turbo we sometimes had this depending on where we got fuel.
Quote from: shnazzle on June 9, 2021, 22:19Could try a coupe of bottles of octane booster, see if that does the trick? Back when we had the turbo we sometimes had this depending on where we got fuel.
The fuel will most often be bought from the same place, but why would it rev 2000 revs beyond the problem area?
Quote from: Gaz mr-s on June 9, 2021, 22:25Quote from: shnazzle on June 9, 2021, 22:19Could try a coupe of bottles of octane booster, see if that does the trick? Back when we had the turbo we sometimes had this depending on where we got fuel.
The fuel will most often be bought from the same place, but why would it rev 2000 revs beyond the problem area?
Revs are different from load. Does it happen regardless of whether she feathers in the throttle in 2nd/3rd etc or whether she goes for it?
Quote from: shnazzle on June 9, 2021, 22:34Quote from: Gaz mr-s on June 9, 2021, 22:25Quote from: shnazzle on June 9, 2021, 22:19Could try a coupe of bottles of octane booster, see if that does the trick? Back when we had the turbo we sometimes had this depending on where we got fuel.
The fuel will most often be bought from the same place, but why would it rev 2000 revs beyond the problem area?
Revs are different from load. Does it happen regardless of whether she feathers in the throttle in 2nd/3rd etc or whether she goes for it?
When I go for it. Gently does not cause the issue.
Quote from: deviantmr-s on June 9, 2021, 22:49Quote from: shnazzle on June 9, 2021, 22:34Quote from: Gaz mr-s on June 9, 2021, 22:25Quote from: shnazzle on June 9, 2021, 22:19Could try a coupe of bottles of octane booster, see if that does the trick? Back when we had the turbo we sometimes had this depending on where we got fuel.
The fuel will most often be bought from the same place, but why would it rev 2000 revs beyond the problem area?
Revs are different from load. Does it happen regardless of whether she feathers in the throttle in 2nd/3rd etc or whether she goes for it?
When I go for it. Gently does not cause the issue.
Thought so. Try some more octane booster, see if it's any better but something has changed. It sounds protection kicking in. It's not liking the o2 readings, knock or misfires it's getting and cutting spark.
What spark plugs? Coil-packs definitely 2zz coil packs? Did it start after they were put in?
Air filter clean?
Is the belt keeping tension? Might be slipping on the harsh acceleration and not supplying the air the trims are expecting, then picking up once it's spinning fully again?
At least 2 coilpacks were changed..... they are different from 1zz - they don't fit. The running improved.
The correct NGK copper plugs are in
Air filter....it's a paper cone....Pipercross if I remember correctly. I was going to make up a filter with foam that Petrus mentioned, & the short existing one in front of the battery is LOUD. So I rigged up a temporary longer intake looking for torque, & keeping the maf a good distance from the t/body.
The car didn't run well...."and it doesn't sound as good...."
So the Pipercross was reinstated & set further left to keep the maf further left.
Literally could be anything at this point causing either too little or much of something or another. Just needs going down the list of things. Belt slip is a very good shout.
Quote from: Call the midlife! on June 9, 2021, 22:58Is the belt keeping tension? Might be slipping on the harsh acceleration and not supplying the air the trims are expecting, then picking up once it's spinning fully again?
Don't know, but flooring the throttle & creating torque, it takes off. And in 2nd & 3rd, once through the hesitation, it accelerates hard.
Sounds ignition related.
Also, which ECU?
Quote from: Alex Knight on June 9, 2021, 23:38Sounds ignition related.
Also, which ECU?
Corolla
Change o2 sensors? Maybe in open loop it's fine but once in closed loop the feedback is false.
You could try closing the plug gaps. try 0.6mm
Let's not overload the op with stuff.
What's easiest and cheapest to start with.
Clean Maf?
Gap plugs?
Make sure it's brimmed with fresh super unleaded?
Correct tension on supercharger belt.
Go from there.
Thanks for the helpful posts folks, we can look at those in the next few weeks. (distance apart) According to what I read when we bought it, the engine doesn't need super-unleaded. I have heard the occasional knock when I've had the car, but it's only when being careless at very low revs. She has a lead-foot, but when checked, the mpg has been very good.
Octane booster has been ordered.
I think with something like that it's always worth just checking the connectors.
My car had developed a stutter/hesitation that I couldn't diagnose last year - ended up being when I took the cam sensor clip off I had cut a tie wrap. A tiny bit of plastic from the tie wrap had lodged in the connector plug. Whilst it was still connected, it was enough to make the contact not perfect.
It's a 5 minute job to check the plugs for corrosion or what
Sounds obvious, but any pending/stored ECU fault codes?
I would argue there should never be any knock, no matter what load. And I would also argue that super-unleaded is the only way to go on a high-compression engine with an added supercharger. Partially because the super-unleaded meets higher standard and there's much more variability in the normal unleaded. especially if the unleaded is E10. You could literally have up to 10% ethanol in there which, on a high-strung car like that, to me is a bit of an no-no unless it was mapped for flex-fuel
Quote from: Alex Knight on June 10, 2021, 10:30Sounds obvious, but any pending/stored ECU fault codes?
None
Quote from: shnazzle on June 10, 2021, 10:43I would argue there should never be any knock, no matter what load. And I would also argue that super-unleaded is the only way to go on a high-compression engine with an added supercharger. Partially because the super-unleaded meets higher standard and there's much more variability in the normal unleaded. especially if the unleaded is E10. You could literally have up to 10% ethanol in there which, on a high-strung car like that, to me is a bit of an no-no unless it was mapped for flex-fuel
Agreed if you heard knock it was very bad news, even knock you cant hear without listening device is causig potential damage.
Im guessing the car is run on supermarket normal unleaded ? if so that could well be the problem as above a highly stressed car like this will benefit from Super unleaded especially if driven hard like you say, sure yes it will run on cheap normal fuel but is it the best thing, absolutely not imo.
The Ecu will adapt to knock from poor fuel to a degree but isnt a guaranteed failsafe, you should not be able to hear knock no matter how you drive it if everything is well.
Octane booster is nasty stuff i wouldnt bother personally but as a stop gap to see if it makes a difference worth a shot, i dont like it as you never know just how much difference its making unless you are very careful with how much fuel you add it to etc, also its usually pretty corrosive stuff and as some will no doubt make it down into the oil its not a good thing, better to just use high quality fuel imo or get car mapped for the cheap stuff if thats what you want to run...of course you will then need and mappable ecu so not so simple or cheap anymore.
Hope you get it sorted :)
When Patrick first mentioned octane booster I thought that super unleaded would be worth trying, but before any conversation occurred between myself & MsSupercharged, she'd already ordered it.... ::) ;D
Quote from: shnazzle on June 10, 2021, 10:43I would argue there should never be any knock, no matter what load. And I would also argue that super-unleaded is the only way to go on a high-compression engine with an added supercharger. Partially because the super-unleaded meets higher standard and there's much more variability in the normal unleaded. especially if the unleaded is E10. You could literally have up to 10% ethanol in there which, on a high-strung car like that, to me is a bit of an no-no unless it was mapped for flex-fuel
I agree 100% with this.
The 2zz is a high compression engine you're now adding boost which ups the effective compression ratio even higher. It surely needs a minimum of 97 Ron fuel.
@Ardent what does toyota specify for the tte turbo?
@Carolyn what fuel do you use on the supercharged 1zz?
Quote from: 1979scotte on June 10, 2021, 12:34Quote from: shnazzle on June 10, 2021, 10:43I would argue there should never be any knock, no matter what load. And I would also argue that super-unleaded is the only way to go on a high-compression engine with an added supercharger. Partially because the super-unleaded meets higher standard and there's much more variability in the normal unleaded. especially if the unleaded is E10. You could literally have up to 10% ethanol in there which, on a high-strung car like that, to me is a bit of an no-no unless it was mapped for flex-fuel
I agree 100% with this.
The 2zz is a high compression engine you're now adding boost which ups the effective compression ratio even higher. It surely needs a minimum of 97 Ron fuel.
@Ardent what does toyota specify for the tte turbo?
@Carolyn what fuel do you use on the supercharged 1zz?
The good stuff. 97Ron.
Quote from: Gaz mr-s on June 9, 2021, 23:10At least 2 coilpacks were changed..... they are different from 1zz - they don't fit. The running improved.
The correct NGK copper plugs are in
Air filter....it's a paper cone....Pipercross if I remember correctly. I was going to make up a filter with foam that Petrus mentioned, & the short existing one in front of the battery is LOUD. So I rigged up a temporary longer intake looking for torque, & keeping the maf a good distance from the t/body.
The car didn't run well...."and it doesn't sound as good...."
So the Pipercross was reinstated & set further left to keep the maf further left.
It does sound ignition related. What kind of coil packs were replaced, generic or OEM new Denso?
I have at one time added faulty performance aftermarket coils and it created these same issues you are describing and what was remarkable is there was no CEL tripped when it would hiccup. Once I returned and replaced with new Denso coil packs the whole system was back to normal.
I found out from others experience at the time that having one defective coil is all it takes to make it run irregular not at idle but when driven at certain loads.
I mean, it sounds exactly like what we had with the turbo we had. The only thing that solved it was changing ECU. Or, of course, we could have had the piggyback remapped. As you're using an OEM ecu, it's clearly not the "tune" that's off, but the parameters it is working with.
Summarising above;
- try super unleaded/octane booster (agreed with thetyrant, use octane booster to quickly diagnose, not as a solution. I only said octane booster so that you didn't have to empty your tank and fill it up again :) )
- Some basic OBD2 checks
- Misfires
- fueling (spiking lean/rich on load?)
- o2 sensor voltages look as expected? Nothing flatlining? Don't know if you still have EML light enabled after swap.
- vacuum (sign of leaks?)
- check that spark plugs are correct for the Corolla 2zz SC. Guessing same gap but colder.
- wiggle all the coil-pack wiring and re-plug. check that coil-packs are in securely.
- clean MAF, ensure no leaks
- check belt. Make sure it's tight (not too tight) and clean.
Quote from: shnazzle on June 10, 2021, 14:48I mean, it sounds exactly like what we had with the turbo we had. The only thing that solved it was changing ECU. Or, of course, we could have had the piggyback remapped. As you're using an OEM ecu, it's clearly not the "tune" that's off, but the parameters it is working with.
Summarising above;
- try super unleaded/octane booster (agreed with thetyrant, use octane booster to quickly diagnose, not as a solution. I only said octane booster so that you didn't have to empty your tank and fill it up again :) )
- Some basic OBD2 checks
- Misfires
- fueling (spiking lean/rich on load?)
- o2 sensor voltages look as expected? Nothing flatlining? Don't know if you still have EML light enabled after swap.
- vacuum (sign of leaks?)
- check that spark plugs are correct for the Corolla 2zz SC. Guessing same gap but colder.
- wiggle all the coil-pack wiring and re-plug. check that coil-packs are in securely.
- clean MAF, ensure no leaks
- check belt. Make sure it's tight (not too tight) and clean.
Thank you for your responses, very helpful. I am using the octane booster to diagnose as have three quarters of a tank left. I have a list to work through now, so thank you everyone for taking the time to help.
I will let you know how I/we get on.
;D
Reset the ECU after filling the tank.
The question was asked previously if the eml works....it doesn't. So it's regularly OBD checked. Coilpacks have been mentioned as a possible problem-source.
When the car was bought & work was done to sort out some issues it had misfire codes. So two coilpacks were replaced...new aftermarket.
If coilpacks are again an issue, why are there no codes?
Quote from: Gaz mr-s on June 11, 2021, 19:42The question was asked previously if the eml works....it doesn't. So it's regularly OBD checked. Coilpacks have been mentioned as a possible problem-source.
When the car was bought & work was done to sort out some issues it had misfire codes. So two coilpacks were replaced...new aftermarket.
If coilpacks are again an issue, why are there no codes?
There is a chance the misfire is just below the OBD threshold (which I have no idea if it will be consecutive counter or a counter over a period of time or a mix of both).
Is there any chance you can try with 4 identical coil packs? and reset the ECU before that.
Quote from: potge
Is there any chance you can try with 4 identical coil packs? and reset the ECU before that.
/quote]
We're looking at getting some.
Quote from: 1979scotte on June 10, 2021, 12:34Quote from: shnazzle on June 10, 2021, 10:43I would argue there should never be any knock, no matter what load. And I would also argue that super-unleaded is the only way to go on a high-compression engine with an added supercharger. Partially because the super-unleaded meets higher standard and there's much more variability in the normal unleaded. especially if the unleaded is E10. You could literally have up to 10% ethanol in there which, on a high-strung car like that, to me is a bit of an no-no unless it was mapped for flex-fuel
I agree 100% with this.
The 2zz is a high compression engine you're now adding boost which ups the effective compression ratio even higher. It surely needs a minimum of 97 Ron fuel.
@Ardent what does toyota specify for the tte turbo?
@Carolyn what fuel do you use on the supercharged 1zz?
98
Quote from: potge on June 11, 2021, 20:04Quote from: Gaz mr-s on June 11, 2021, 19:42The question was asked previously if the eml works....it doesn't. So it's regularly OBD checked. Coilpacks have been mentioned as a possible problem-source.
When the car was bought & work was done to sort out some issues it had misfire codes. So two coilpacks were replaced...new aftermarket.
If coilpacks are again an issue, why are there no codes?
There is a chance the misfire is just below the OBD threshold (which I have no idea if it will be consecutive counter or a counter over a period of time or a mix of both).
Is there any chance you can try with 4 identical coil packs? and reset the ECU before that.
It is believed that might be the case and the faulty coil not giving the ECU the signal the coil misfired.
This is a known issue with generic aftermarket coils. Sometimes they work initially and get worse in a short period of time, and if you have one bad one it creates glitches in the form of hesitation from the entire ignition system.
The factory Denso coils are expensive but worth it.
Coil packs were changed and it runs considerably better. The drive down to Wrexham and back put the smile back on my face. Running completely now on 99 ron, where as before I ran a mixture of standard and premium.
I will however be keeping a close eye on it.
Thank you for all your help. ;D
Quote from: deviantmr-s on July 18, 2021, 21:09Coil packs were changed and it runs considerably better. The drive down to Wrexham and back put the smile back on my face. Running completely now on 99 ron, where as before I ran a mixture of standard and premium.
I will however be keeping a close eye on it.
Thank you for all your help. ;D
Keep putting 99 in it and you'll be fine.
Hopefully it's all sorted
Quote from: Dev on June 11, 2021, 21:11It is believed that might be the case and the faulty coil not giving the ECU the signal the coil misfired.
This is a known issue with generic aftermarket coils. Sometimes they work initially and get worse in a short period of time, and if you have one bad one it creates glitches in the form of hesitation from the entire ignition system.
The factory Denso coils are expensive but worth it.
This seems to have been the case. When the car was bought I think all 4 were Denso, but it had misfires, & they did produce OBD codes. Nothing helpful like this with the Aftermarket in. When we got 3 replacement Denso, (1 new, 2 used) we discovered that of the current ones, 3 were aftermarket.
Caroline says there is still a slight hesitation in 4th gear only, so we're going to get a couple more new ones from the US because without any kind of offer they cost over £60 each here.... :o >:(
Quote from: Gaz mr-s on July 19, 2021, 08:32Quote from: Dev on June 11, 2021, 21:11It is believed that might be the case and the faulty coil not giving the ECU the signal the coil misfired.
This is a known issue with generic aftermarket coils. Sometimes they work initially and get worse in a short period of time, and if you have one bad one it creates glitches in the form of hesitation from the entire ignition system.
The factory Denso coils are expensive but worth it.
This seems to have been the case. When the car was bought I think all 4 were Denso, but it had misfires, & they did produce OBD codes. Nothing helpful like this with the Aftermarket in. When we got 3 replacement Denso, (1 new, 2 used) we discovered that 3 were aftermarket.
Caroline says there is still a slight hesitation in 4th gear only, so we're going to get a couple more new ones from the US because without any kind of offer they cost over £60 each here.... :o >:(
The aftermarket ignition coils come in all types from very cheap to rebranded Denso coils. Its hard to know what you are getting but a good indicator is the price and the feel of the plastic being thin. What I believe happens is the quality of the windings is not there and over time with heat the coatings wear and it starts to short progressively leading to misfires but since the aftermarket coil cuts corners it doesn't always send a signal to the ECU that it has misfired.
The OEM Denso coils also shorts over a period of time gaining in resistance. I have tested this on a multi meter comparing old coils and new ones but there was no way to use that as a guide to know if the coil is tired.
I then did some searching and found that these ignition coils go bad like most things electronic even if they sit brand new for a very long time due to deterioration and atmospheric corrosion. This also happens with ECUs and just about anything electronic. Time is your enemy.
In a nut shell I would not use used ignition coils. I have found that although I did not have any faults with my old ignition coils they were tired being 13 years old and once I put a fresh pair in the car felt like it gained 10hp and was lively. Therefore I believe it is a good investment to refresh the ignition coils with new stock every 10 years with a new set of plugs for peak performance.