2JZ GE 24+1 trigger issue at 6500

[jasaircraft]

Hi, I have a strange triggering issue, at 6500rpm Im using a jbperf 2.1 ... I remember that the way the variable resistors where from factory on the main board it wouldnt sync well to start and after playing with them it synced fine reads fine from start etc, just that issue at 6500rpm.

I first thought it was an afr issue and managed to get to around 11.3:1 on the problem area but of course since it kinda misfires the afr reading isnt stable enough, then after testing with the vehicle standing still I realized it would also have that hicup so I saw that rpm fluctuates a bit erratically in that area.

I did composite, sync err, tooth and trigger datalogs at 6500 while the issue happens that I dont really understand but if someone could help would be great, Im also posting my msq

[jasaircraft]

help please!!!!

[jasaircraft]

I forgot to add that using the jimstim and using a subaru msq I had great sync way past 6500rpm, so very strange there... maybe trigger angle? Limiter is set at 7000rpm with 200 rpm hysteresis

[racingmini_mtl]

Try putting a 10k resistor between VR+ and VR-.

Jean

[jasaircraft]

Hi Jean, This 10k resistor would be between the trigger signal (crank) and its negative right?

[nathaninwa]

Correct, i have a 1k between vr pos and neg on my install

[jasaircraft]

Jean It helped quite well, its now doing it at 6800rpm but since its basically at the limiter thats good enough I guess, are you using that 1K on a 24+1 type of trigger wheels? 2JZ?
heres a datalog

[racingmini_mtl]

Adding a shunt resistor can be a compromise between high and low revs. Usually a 1k to 10k resistor does work but a low resistance value might kill the signal at low revs. So you could try to go to a lower value (anything from 1k to around 5k) and if you don't have any starting sync issues then use it. The lower value should push the high rev issue well outside your usable RPM range.

Jean

[jasaircraft]

oh thats great! I will take note of that on my builds log

[jasaircraft]

should we also add one for the cam signal?

[racingmini_mtl]

If you don't have sync issues, don't add one. And the cam signal is less likely to need it.

Jean

[jasaircraft]

just solved my sync issue at 5krpm on a 2jz-ge vvti by adding a 8kohm inline in crank VR+ signal wire. (no resistor across needed in my case).
putting both pots anticlockwise and then moving r56 (bottom one) clockwise around 6 turns (or until it can start and reach 7krpm)

Not sure if pots on the upper board (expansion) affect.
Filtering options all OFF

this on the 2jz vvti trigger option, rising edge, shielded on one side wires for both sensors. Also using a Jbperf board for extra help too ;)