Update 2011-05-02

I have similar problem.Car has VR on crank, 60-2 and one impulse per cam rotation.

Trigger log captured with 1.1.90

So everything in trigger log is good.

Log when cranking:

1 of 20 cranking vems has rpms.

With 1.1.74 and 1.1.89 car start every time.

With 1.1.90 it's very hard start car, but every time triggerlog is good.

With 1.1.90 and disable cam syn(sec sensor) car starts every time.

Both(primary and secondary) wires are shielded.


Did you measured pullup voltage on the sensor wires?

Connect laptop speaker output to sensor connector, first use primery signal for testing both sensors.( cranck and cam with cam turned off)

I found if voltage diffrence over sensor is to small you get a error to big also generates a error.

How big is the gap between sensor and tooth? Wider then +- 1mm generates bytes but not a signal.

Update 2011-05-02

Not so sure what to make of this any more. My collected data is not good enough for me to be satisfied and for you to spend any significant amount of time on it, so I will make better documented tests in a week when conditions are better (car is outside, cold wind along with rain mixed with snow, etc..).


The engine is a Volvo 4 cyl, with 8 valve head, aggressive cams and tuned with Alpha-N. Injectors are Siemens/Deka 630 cc/min (12 Ohm) and it uses a Bosch Motorsport coilpack.

Trigger type is C004 with cam sync, using two +12V fed Honeywell GT1 so there is no load on pin 28 and only TPS uses pin 29. Trigger wheel is simply two teeth on the crank and a cam sync tooth on the intermediate shaft (rotates at cam speed).


The firmware initially used was 1.0.73, after a year I upgraded to 1.1.79 and it worked very well. We wanted the new features with injector angle curve that came with 1.1.80 because with a single throttle and aggressive cam the fuel injection timing is important.

I upgraded to 1.1.88 and RPM was zero at all times except when I disabled cam sync as a test. With cam sync turned on, the "Running On/off" status flag flashes when the primary trigger has events, but still RPM = 0. The triggerlog looks just clean and healthy - and why shouldn't it, all we changed was firmware.

I tried downgrading from 1.1.88 to 1.1.81, same results. RPM only returned with disabled cam sync. Two weeks later I tried 1.1.90 experimental from Marcell and couldn't even make a triggerlog, results were empty even though bytes were received:

I disabled cam sync and started the car (50/50% chance of starting) with 1.1.90 and warmed it up. Then I downgraded to 1.1.78 so the owner could move it around easily on his property.

Today I returned and upgraded to 1.1.90 again to get a longer triggerlog for use in the test bench in the office. I confirmed that I got no rpm with cam sync enabled, then disabled cam sync and made a triggerlog. Inexplicably it seems the cam sync pulse is visible in this triggerlog as primary events??

An earlier question from Marcell was if this could be noise? I removed fuses for everything but the ECU and now it worked, I had rpm with cam sync. However only on the third cam sync signal did the spark events occur in the datalog

I then put the fuses back and now I could still get RPM ? I was confused at that point, a brief word with Jörgen and we came to the conclusion that it might be bad spark plugs that caused a second problem because they were not in good condition after some cold hard-to-start situations and could cause radio interference.

Some basic questions: