2JZ VVTi RPM issue

[Jo LeForce]

When using a base map to start a 2JZ VVTi (Storm blue ECU) RPM is cutting at around 5200rpm significantly short of the set RPM limit. The cut sounds different than the normal cutoff sound & it takes place only when TPS is at 100%. If TPS is any less than 100% RPM would reach the set rev limit. I used a different base map & the issue got cured! I ran a compare between the 2 files & among the many differences I suspect two.

1- VVTi cam solenoid is set on AUX2 on both files: Good file: Inlet/LH at 300hz frequency. Bad file: Inlet/RH at 20hz frequency 

2-Triggers, trigger 2 VVT offset: Good file: Inlet/LH 657 ATDC. Bad file: Inlet/LH 173 ATDC.

Would any of the above differences cause such issue?

Should I look for other differences to pinpoint the issue?

Thanks

[JMP]

have you done the basics, followed the setup guide and checked the offset with timing light, then checked the VVT offset following the instructions in the help file?

On my vvti 2J, I ended up with a trigger offset of 205 and a vvt offset of 170.  The VVT should be configured as inlet/LH (for both the VVT Aux output cam type and the trig 2 cam type).  I ran the solenoid at 175Hz on my engine and it controlled perfectly.  Firing order 1-5-3-6-2-4

[Adamw]

The 1JZ settings in the help file will be a good starting point.

 

Still, I dont think any of those settings you mention would give you a misfire.

Im not sure if the ignitor on that engine is the same as the non-vvti 2JZ but if it is, those are very sensative to current and dont like much dwell.  Try a dwell table like below to see if it helps.  If not you need to provide some logs.

[muzzytt]

Jo 

just to share my experience My values are similar to what you call bad.

 

my offset is 173

 

my vvt cam solenoid is set to 175hz in the aux output

[Jo LeForce]

I did more testing & non of the base maps seemed to work with the RPM always halting at around 5200-5500RPM, very short of the set RPM limit! Then I went through a long process of elimination changing the following to no avail:

Spark plugs, cam, crank, TPS sensors, coils, the entire wiring loom. Dwell table looked conservative enough considering that I'm using gray coils from a Subaru STi.

I finally did something that strangely solved the issue & got RPM to hit the set limit with the very normal & distinctive cutoff sound. I decreased master fuel from 12ms to 8ms & that somehow took care of the problem! Although AFR was semi fine at around 12AFR at the point when the rpm halted. Now, at 8ms fuel readings got lean all over & I had to add significant fuel in the main table so the car could idle fine bringing AFR from 19 down to around 14.

Any clue what just happened before I proceed & tune the rest of the fuel table with master fuel set at 8ms?

Is it possible that the injectors power consumption at higher duty cycles might be preventing the coils from generating enough spark?

BTW, the injectors are ID1000 with fuel pressure at 43psi

[muzzytt]

Mine is at 8ms too dunno why yours was at 12?

[Adamw]

I finally did something that strangely solved the issue & got RPM to hit the set limit with the very normal & distinctive cutoff sound. I decreased master fuel from 12ms to 8ms & that somehow took care of the problem! Although AFR was semi fine at around 12AFR at the point when the rpm halted. Now, at 8ms fuel readings got lean all over & I had to add significant fuel in the main table so the car could idle fine bringing AFR from 19 down to around 14.

Any clue what just happened before I proceed & tune the rest of the fuel table with master fuel set at 8ms?

Is it possible that the injectors power consumption at higher duty cycles might be preventing the coils from generating enough spark?

Reducing master fuel, then increasing numbers in the main table basically achieves very little, the aim usually is to adjust the master so that you have numbers of around 50% in the middle of your fuel table, but that is not normally very critical. For 1000cc injectors a master of 8 will be fine. 

 

Is it possible that the injectors power consumption at higher duty cycles might be preventing the coils from generating enough spark?

BTW, the injectors are ID1000 with fuel pressure at 43psi

Unlikely unless wiring is particularly bad.  6 x ID1000's will only pull about 5 Amps max total.

 

A log will be the next step if you continue to have drama:  https://www.youtube.com/watch?v=_P1LRANeO4A