Emu Black- Porsche 911 - Cam Sync Issue at higher rpm - Hall Effect Sensor ZF/Cherry

I’m running an EMU black on an older Porsche 911 with turbo. Using a couple of these ZF sensors below for crank and cam position.
Car was running well for months then out of the blue, would miss/backfire for a split second at higher rpm and under load.
Not boost cut, fuel cut or ignition cut etc… no where near those limits.

Log showed that Cam Sync Tooth was dropping out for a split second and also showing a coil dwell error. As time has gone on, it has become easier to provoke it to miss/backfire.

In the software, the 'Disable Cam Sync above rpm" was at the factory 20000… so we lowered it to 2000. Now, the engine runs smoothly with no hint of miss/backfire.
This suggests that the cam sync is the issue, but what do make of the dwell error?

Has anyone used these sensors and had issue?

They are running of the 5V produced by the ecu and grounded to ecu sensor ground.
I’m open to suggestions:

  • we tried changing secondary trigger edge from rising to falling
  • adding a filter
  • raising sensitivity
  • smaller plug gaps (new plugs)

The only thing that appeared to make a diffference, was disabling the cam sync…

Those Cherry sensors do fail from time to time, especially if subject to heat. What air gap are the sensors?
Are you using a crank trigger wheel or the flywheel?

I always have better results with falling edge myself.

Can you post a map and data log of the issue?

I’n on my Mac right now, so cannot post map or log. I’m pretty new to ecu tuning so also learning about logs etc.

The crank trigger is a 60-2 wheel on the crankshaft pulley (not the flywheel end) and the cam trigger is inside a ‘module’ :

The gap for the crank trigger is 1mm… as for the gap inside the module, I cannot tell without opening it up.

There is something about it, having similar case just now with V3 firmware.

Hi Konrad

I haven’t upgraded my software yet…

The owner of Adapt Motorsport (manufacturer of the crank/cam trigger unit) thinks that I should use 12v to power the hall effect sensor not the ecus 5V. He thinks it might be right on the verge of operation hence the reason why it loses sync at higher rpm etc.

The sensor is rated to run 5-24V …

I guess it’s worth a shot!

I use China copy of this sensor for CAM, and power it from 12v.
first connection was in 5v - sync loses on 2000…3000 rpm.
on 12 v - 9000 RPM, no lost sync

Thankyou for replying.
Today I am going to run 12V to this sensor. Do I need to change the ground to connect to Ecu Ground? Or can I leave it as connected to sensor ground?

i used switched 12 v source and Sens GND.

Ok. so today i ‘stole’ the 12v from my boost solenoid and fed it to the cam sensor,leaving the ground connected to sensor ground.
So far, it seems to have cured my problem.

However, when logging, the ‘cam sync trigger tooth’ still fluctuates between 112 and 113… is this significant? I don’t think it did this when it was newer looking at my oldest logs.

I tried to upload my log, but it wont let me attach it…

I would say that sensor edge is falling close to crank senso edge and sometimes is on one sometimes on another side of it … if there is no vvt i wouldn’t really worry about it

I see the same on my engine since i installed emu black 4 years ago. Never had an issue. It is in my engine as u say Greg…cam/crank sensor edges line up and is either on the one or other side.
I don’t think this has an functional impact…even with VVT. The tooth count is just relevant for syncronistation.

Took it for a proper drive today. And when UNDER LOAD and at higher rpm, it drops sync for a split second and tries to re sync. If I new how, I would upload a log and tune file but I dont think I can.

If I build up the revs without using any boost, it will easily redline and not skip a beat. It only drops sync when under load and making boost.

Any ideas?

View post on imgur.com

(Attachment 20240623_1125.emublog is missing)

20240623_1125.emublog.zip (4.0 MB)

Mike here’s your log file.
Guys @ecumaster can you allow the emublog file extension to be added to forum?

1 Like

not see lost in log

In the middle. Cam sync trigger tooth drops to 45 and a lean condition follows, which means there was misfire right? ECU resyncs back and all goes to normal again?

for uneven crank trigger, CAM need only one time - first engine sync. After this, ecu works only on crank trigger.
i think it is some electrical wiring problem