Cam tooth count drops

[Scooter]

I'm encountering an issue with cam signal dropping out. It should be a constant 24 tooth, but occasionally it will drop to 1. This is odd, cause the sync is still present. This issue started, after I swapped transmissions and clutch setup. (2jzge with 7m cps...was on W58 5 spd, but swapped to pontiac ar5 trans.)....Through tech support, we have adjusted the edge rejection angle, under secondary triggers. this does make a slight difference, but its still present.

[Scooter]

currently no resistors in primary or secondary wiring

[WHPZach]

Have you ever tried a resistor inline with the secondary trigger? If you look at the trigger error log channel, you've got some false teeth popping up. A 10k resistor would be where I would start.

[Scooter]

I'll give it a shot. Add a 10k inline to B15, correct?

[Scooter]

Added a 10K resistor inline to B15, cam signal. and still have fluctuations. Added another 10K inline (so 20K) and seems slightly better....attached are the two logs......also fyi I am using prowire PTFE shielded 3x conductor 20g, going to my 7mcps. Shield is grounded to the engine block...could that be an issue?

[Scooter]

I'm seriously contemplating re-doing my entire engine harness.....to rule out any grounding issue or shielding issue. (Keep in mind the car ran great for a 1yr, and this issue reared its ugly head after I pulled the motor to swap to a different transmission)

[derOJ]

have you tried a new sensor?!

[gregpe]

And are you sure edge is correct selected?

[Scooter]

Yes, I have swapped sensors. With the 2jzge motor, the cam and crank signals are builtin to the distributor base. When the issues occured, I did replace it to to a new remanufactured 7MGTE CPS. This is common swap, as the 7mgte is a low profile. This made zero difference in the signal noise. Also, the 7mgte cps pickups can be adjusted for gap distance. this was also verifed to be inspec.

[Scooter]

yes, edge selection is correct. We verified this, by sending multiple scopes back and forth with Ecumaster tech support. My cam tooth is not in the "ideal" "perfectly" centered position between two crank teeth, it is biased in the upper range alittle bit.

[Scooter]

I received another suggestion, that a stretched timing belt may cause noise issues on this setup. If the belt is tight in one section, and loose in another section, it would all translate to the CPS not rotating smoothly..........Also, from the logs I see I do not get any cam tooth fluctuations when the rpms are steady.

[Wisetechscott]

Did you ever find a solution to this? I am experiancing the same thing ( sync tooth drops off for a split second then comes back) . As of right now i have ran a new shielded cps wire loom seperate from the rest of the engi e harness and grounded the shield at the ecu side. This didn't do much for me either.

[Scooter]

I have not proven a solution to this yet. I did replace the timing belt and it was indeed stretched compared to a new one....but I'm in the process of fixing some other things on my engine harness, and should be firing it up in a few weeks.

[Scooter]

Lots of things have changes the past few weeks. I replaced the Timing Belt (theory was that the belt might be stretched causing fluctuations on the 7mgte CPS)....replaced all wiring and re-did entire harness. This was done for many reasons. I was changing injectors, adding flex, adding egt, adding A/C wiring back in, and also added a 36-2 crank trigger wheel..and lastly changed to emublack, so I would have to repin it anyways.

7MGTE CPS is still used for the 1tooth cam sensor, the 36-2 crank wheel is used for the crank trigger. These are prowire tefzel shielded wire. Using the solder-heat-shrink termination for shielded wire.

Oscilloscope shows perfectly clean signal at both 7MGTE and also CRANK. No noise directly from the sensor.

The only way the motor will run is if I set DISABLE CAMSYNC ABOVE 600rpm....any higher the tooth count goes erratic, like my first post picture.

I have tried 10K resistor inline on secondary cam, also 20K resistor inline with cam and made zero improvement. EMUBLACK has builtin 4k7 resistor, and that made no difference.

So, in conclusion. This issue existed on old EMU, old wiring with 2jzGE dizzy. Existed on old EMU, old wiring, 7MGTE CPS. Existed on EMUBLACK, new wiring, 2jzGE dizzy. Existed on EMULACK new wiring 7MGTE. and Existed with multiple resistors.

[Scooter]

Log of erratic camsync

[Scooter]

Disable camsync at 600rpm...and wasted spark ignition...1&6, 2&5, 3&4...runs...and no variation on camsync trigger tooth...thus no variation in ignition timing

[Scooter]

I came up with this idea to easily try various resistors. Using a 2pin weatherpack, with
various jumper resistors.

The solution to my issues was a combination of both primary and secondary. I added a 20K to primary and a 10K to secondary and issues are gone.....Still unknown why signals were perfectly fine with W58 trans for over a year, but with AR5 this issue came up...