3sgte Misfire

[Toliski]

Hi guys i have a problem with my 3sgte.
I set the base timing i make TPS and Map calibration

I change the Dwell times to St185 from st205 (not help)

I increase the dwell time then degrease it (not help)

I try new spark plugs with less gap (not help)

I put exactly the same ignition map with my power fc i try to retard it, to advance it (not help)

But no matter what am i doing the car at 1 bar (maybe and sooner but at 1 bar its very noticeable)  it start to misfire everytime at 5200-5400rpm and then at 5800-6000rpm.

Afr its ok. I have external boost contol.

Finally i plug the PFC again and running fine on every boost to 1.5 bar.

What the issue here? Maybe one of you have the same problem?

https://drive.google.com/open?id=0B0_6FCzctzJLcDVuUkp1VUcxcDA    Log

https://drive.google.com/open?id=0B0_6FCzctzJLc2p5NTNHTjBqcDQ   Map

[Toliski]

I found it!!

I make the values at trigger1 from 3.5 to 2.5 above 5000rpm!

[Brad Burnett]

What you are going to need to do is run a scope trace at all rpm points in the trigger threshold table and set that table correctly.

I have fought with arming thresholds a lot in the past.

[Toliski]

2 hours ago, Brad Burnett said:

What you are going to need to do is run a scope trace at all rpm points in the trigger threshold table and set that table correctly.

I have fought with arming thresholds a lot in the past.

I try to make a trigger scope for cranking with infectors off.

From the time you click capture it love for 1-2 secs only.

I assume that i must to do it for every thousand of rpm and see?

[Brad Burnett]

That is correct.  

Basically the arming threshold table will be set to about 2/3s of the values that you get in the scope trace.

[Toliski]

1 hour ago, Brad Burnett said:

That is correct.  

Basically the arming threshold table will be set to about 2/3s of the values that you get in the scope trace.

I must to read again about trigger scope. I made a quick read but i don't understand how it works!  Thanks for your time Brad

[Adamw]

14 hours ago, Toliski said:

I found it!!

I make the values at trigger1 from 3.5 to 2.5 above 5000rpm!

I have my doubts that this is your problem, it will be interesting to hear if it still seems fixed after more time.

There are no signs of any trigger errors in any of the logs that you have posted to date - dwell and RPM traces are very stable which would usually indicate engine position is calculating well.

Lowering the arming threshold at high RPM would usually cause more errors, not less.

 

4 hours ago, Toliski said:

I must to read again about trigger scope. I made a quick read but i don't understand how it works!  Thanks for your time Brad

Here is some instructions from the help file:

[Toliski]

10 hours ago, Adamw said:

I have my doubts that this is your problem, it will be interesting to hear if it still seems fixed after more time.

There are no signs of any trigger errors in any of the logs that you have posted to date - dwell and RPM traces are very stable which would usually indicate engine position is calculating well.

Lowering the arming threshold at high RPM would usually cause more errors, not less.

 

Here is some instructions from the help file:

I think that the only change above 5000 rpm was the trigger arming from 2.5 to 3 and the 3.5. At the 3.5 the problem occur so i make it 2.5

[Adamw]

43 minutes ago, Toliski said:

I think that the only change above 5000 rpm was the dwell from 2.5 to 3 and the 3.5. At the 3.5 the problem occur so i make it 2.5

Ok, I thought you were originally talking about arming threshold which didnt fit your symptoms well.  Dwell will certainly have an impact on ignition energy which fits your misfire problem better so that could well explain your fix.

[Toliski]

3 hours ago, Adamw said:

Ok, I thought you were originally talking about arming threshold which didnt fit your symptoms well.  Dwell will certainly have an impact on ignition energy which fits your misfire problem better so that could well explain your fix.

Ohh sorry Adam i wrote it in the morning! the arming threshold is the value that i change. I will correct my other post

[Brad Burnett]

@Adamw , not trying to second guess you or anything here, but I have had heaps of cars where I have to "Iron out" the arming thresholds to fix a "misfire" situation.

[Adamw]

5 hours ago, Brad Burnett said:

@Adamw , not trying to second guess you or anything here, but I have had heaps of cars where I have to "Iron out" the arming thresholds to fix a "misfire" situation.

If the arming threshold is too high then then the ecu will start to “skip” the teeth that have the lowest amplitude, if the threshold is too low then the ecu may count “noise” as a real tooth.  Any time the ecu sees more or less teeth (even just 1) than it is told to expect then there will usually be clear symptoms - dwell scatter is usually the most obvious as the ecu struggles to back calculate where to start the dwell from when time period between teeth is varying so much.

Toliski’s logs do not exhibit any of these symptoms.

[Toliski]

2 hours ago, Adamw said:

If the arming threshold is too high then then the ecu will start to “skip” the teeth that have the lowest amplitude, if the threshold is too low then the ecu may count “noise” as a real tooth.  Any time the ecu sees more or less teeth (even just 1) than it is told to expect then there will usually be clear symptoms - dwell scatter is usually the most obvious as the ecu struggles to back calculate where to start the dwell from when time period between teeth is varying so much.

Toliski’s logs do not exhibit any of these symptoms.

I try to make a trigger scope at 5 and 6 thousand rpm with stopped car and see tomorrow.

Question about Iacv guys, when i am on part throttle it's at 40 or what ever value i set the limits at close loop idle. But when i am at boost it goes to zero percent to close the circuit?

I have my iacv connected with a small breather not at airbox so if it doesn't seal i lost boost from there.

[Simon]

The IAC will remain at the base position for all times other than when throttle is closed and it is controlling the idle.

The IAC should really be plumbed back into the intake between the turbo and throttle butterfly.

For some reason Toyota did not do this factory.

[Toliski]

9 hours ago, Simon said:

The IAC will remain at the base position for all times other than when throttle is closed and it is controlling the idle.

The IAC should really be plumbed back into the intake between the turbo and throttle butterfly.

For some reason Toyota did not do this factory.

Are you sure that i should plumb it there?

I think with stock ecu when you are on boost the Iac is sealed.

[Simon]

On the stock set up I think they close the valve. We do not so you will have a boost leak if it is not plumbed to the intake between the throttle and turbo.

This way when on boost the pressure across the valve will be equal.

[Toliski]

13 minutes ago, Simon said:

On the stock set up I think they close the valve. We do not so you will have a boost leak if it is not plumbed to the intake between the throttle and turbo.

This way when on boost the pressure across the valve will be equal.

Ok Simon thank you.

[rrob]

1j and 2j have a 1 way valve as part of the idle assembly. No need for it to be boost referenced.

[Toliski]

Question guys, I understand the trigger 1 arming and I set it right. The trigger 2 arming is following the values of 1?

If not, at 3000rpm i have constant 0 volt on trigger scope and make one pulse at 7 volt maybe two per capture. And at 6000 rpm make 12 volt pulse. What i must divine here?

17 hours ago, Simon said:

On the stock set up I think they close the valve. We do not so you will have a boost leak if it is not plumbed to the intake between the throttle and turbo.

This way when on boost the pressure across the valve will be equal.

Simon i do it like you say and works great thanks!

4000.llg

5200.llg

6000.llg

3000.llg

[Adamw]

Trigger 2 arming should be done separate to trigger 1.

Based on your scopes I would set arming like this:

RPM     Trig1    Trig2

3000     2.0v      3.5v

4000     2.5v      4.5v

5000     3.0v     5.0v

6000     3.0v     6.0v

[Toliski]

8 hours ago, Adamw said:

Trigger 2 arming should be done separate to trigger 1.

Based on your scopes I would set arming like this:

RPM     Trig1    Trig2

3000     2.0v      3.5v

4000     2.5v      4.5v

5000     3.0v     5.0v

6000     3.0v     6.0v

Thanks Adam. My trigger 2 is wayyy off!!