2jz wont rev at 2800!!

[RHD]

this is driving me a bit mad its like a rev limit that starts at exactly 2780 and completely flatlines the rpm at 2800 until MAP gets right up to about 80Kpa then it will break through and rev cleanly again!!!

of course as soon as it misfires the AFR goes completely lean but if you follow the injector DC or PW there is nothing unusual happening with the fuel there, and therr are no sync or trigger errors!

Edit: Note the log is all made free reving not driving!... so at 80kpa and 3000rpm the misfire is extremely severe!!

[PSI-Motor]

Please post a Scope.

[RHD]

ok i didnt save the scope but it all looked ok, i will take one next time i am there

[Karel]

Try to lower down DWELL time. Tell if it reacts on changing the DWELL at all.

[RHD]

Try to lower down DWELL time. Tell if it reacts on changing the DWELL at all.

That is the first thing i tried.... higher or lower makes no difference at all. i also tried running in wast spark settings

I should Add im still using the original wiring and igniter but the car was running fine previous to the install.

[Jadzwin]

The log looks correct (no trigger issues). It is very strange. What firmware do you use ?

[RHD]

generally I always try use the latest version so i am using 149 I will try reloading/updating to 150 it next time i go there

[Jadzwin]

It doesn't seem to be firmware related problem

[ATS_Scott]

I have noticed with the 3sgte that I won't see any trigger error unless advanced filtering is selected... It's turned off here.

Kuba, Is that coincidental, or does filtering need to be on to see trigger error if there is any?

[RHD]

this is getting a little bit frustrating!!

we changed the igniter and we put a timing lite on its definately spark related as the timing lite cuts out at the same time and its happening on almost ALL cylinders

I cant help thinking if it was hardware related coils or wiring etc it would happen at other rpm too?

here is scope with it missing, with it idling and with the primary edge reversed

video here https://youtu.be/A0XxdacMdO8

[Karel]

I was looking to your logs again..... looks like this must be fuel related.
Your AFR goes lean (thanks missfire may be), but it looks like somthings wrong on your fueling.

2300RPM=1,92ms
2800RPM=3,92ms .................... i think too rich
4500RPM=1,6-2,3ms

so i think its fuel related.

Try slowly cell by cell correct the AFR.......... (and may be turn off the accel enrichment for the tests)

And what i also found its voltage fluctulation.

in "normal" idle you have 13,77-13,89V
at the "wrong" area 12,73-13,89V

so may be some grounding issue or just the voltage regulator does not work so accurate ? I would normaly not care about it, but if you are searching for issue.............

I was looking in my logs from other 2JZ engines and i have higher voltage up to 14,65V but also this "noise"

[Kisielisodd]

I went through whole project and looks like, there is no mistake in settings.

Did You try change sensitivity switch to lower RPM in secondary trigger ? (lower the 2500 rpm before miss firing occurs ?)
Consider also reduce or add the values on VE map around 2800 RPM for 40 - 70 kpa. May be it is to lean or to rich, I can't decide. We newer seen behavior like this.

[RHD]

thank you for suggestions.. but i have wasted many hours on this!

Fueling was the first thing i played with and most certainly did not affect anything too much I think the sudden leanness is caused by the massive misfires. if you follow the injector pw and dc nothing unusual happens at that exact rpm point. Then i played with dwell and trigger settings sensitivity sw etc etc

The true sign that it is spark related is when we added timing lite and this went from flashing consistently to flashing sporadically when it was missing and back to consistently again once it went past!

[Karel]

thank you for suggestions.. but i have wasted many hours on this!

Fueling was the first thing i played with and most certainly did not affect anything too much I think the sudden leanness is caused by the massive misfires. if you follow the injector pw and dc nothing unusual happens at that exact rpm point. Then i played with dwell and trigger settings sensitivity sw etc etc

The true sign that it is spark related is when we added timing lite and this went from flashing consistently to flashing sporadically when it was missing and back to consistently again once it went past!

But if you look into your log you can see executed spark count............ so you can watch if your ecu wants to fire or not. And i see that the emu wants to spark, even if you report ign cut.

I have seen "behavior" like that many times.... sometimes it was bad idle setting, bad VE map, bad edge on cam/crank, also one times wrong wired up alternator caused noise in power line, wrong relay .... So basicly many reasons.

I think you are very good tuner, so it must be something, what is not seen on diagnostics...... so some suggestion:

You know for sure about "fuel pump controler" in Supra, do you ? May be you are really lean, just because the pump is on "lowload" modus and becomes too low voltage, but if you are over the 3000RPm it get fully powered. Did you checked fuel pressure on this condition ?

I bet, must be something like that.

[RHD]

thank you for suggestions.. but i have wasted many hours on this!

Fueling was the first thing i played with and most certainly did not affect anything too much I think the sudden leanness is caused by the massive misfires. if you follow the injector pw and dc nothing unusual happens at that exact rpm point. Then i played with dwell and trigger settings sensitivity sw etc etc

The true sign that it is spark related is when we added timing lite and this went from flashing consistently to flashing sporadically when it was missing and back to consistently again once it went past!

But if you look into your log you can see executed spark count............ so you can watch if your ecu wants to fire or not. And i see that the emu wants to spark, even if you report ign cut.

I have seen "behavior" like that many times.... sometimes it was bad idle setting, bad VE map, bad edge on cam/crank, also one times wrong wired up alternator caused noise in power line, wrong relay .... So basicly many reasons.

I think you are very good tuner, so it must be something, what is not seen on diagnostics...... so some suggestion:


You know for sure about "fuel pump controler" in Supra, do you ? May be you are really lean, just because the pump is on "lowload" modus and becomes too low voltage, but if you are over the 3000RPm it get fully powered. Did you checked fuel pressure on this condition ?

I bet, must be something like that.

thank you for many suggestions! fuel pressure is actually logged .... and is fine
... executed spark count looks ok too,

I will go there tomorrow again and maybe use oscilloscope to trace the signals at various points from ecu to igniter and to coils, i think will be the only way to find the source of problem!

[cwtt]

Shouldn't your coils be fired 1-5-3-6-2-4

[RHD]

Shouldn't your coils be fired 1-5-3-6-2-4

it actually is, the sequence has just been started in a different position to better suit the position of the cam sync signal

[ihiryu]

Any update on this??

Could it be a faulty MAP sensor??

[RHD]

Actually there is. We tested all the signals then we pulled off the fuel lines double checked the pressures etc then the problem just went away!! so we have no idea what was causing it and weather or not it will return!!! we think maybe just an air lock in the fuel rail?? it has a non return rail and external reg.

[ihiryu]

How do you have an external regulator without a return line??

It's possible an air lock would do it. We have had a 350z do the same thing. Car was completely stock, come to find out, the plastic fuel pump housing had a very small crack in it, so when it was low on gas, it would make a horrible noise (pump trying to pump fuel and air).

I hope that is the problem.