This concerns C004 trigger with cam sync. I have an engine with a problem with recent firmwares, it's a Volvo 4 cyl that has 2 teeth on the front accessory pulley and camsync on the intermediate shaft (rotates at cam speed). It uses a wasted spark coilpack for ignition so it needs the cam sync. It ran with 1.0.73 for a long time, then I upgrade to 1.1.79 a little less than a year ago, and this setup was tuned and worked.
Here comes the problem, we wanted the new features with injector angle curve that came with 1.1.80, so upgraded to 1.1.88 as it would be really interesting to tune the injector angle curve as it is an Alpha-N tuned engine with lots of valve overlap, Speed-Density doesn't work well except for full throttle (no good pressure signal).
But RPM was zero at all times, except when I disabled cam sync as a test. The "Running On/off" status flag flashes when the primary trigger has events, but 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.
- Triggerlog, a bit short, but looks ok : [ c004-camsync-issue.triggerlog.txt]
- is it possible that something prevented sparks or injection (and starting) at the time the triggerlog was captured ? Like fuse, or ign/INJ connector removed ?
- The 1.1.88 config : [1.1.88.vemscfg]
Config files for 1.1.79 (original that ran) and all files are here :
http://www.vems.hu/files/MembersPage/MattiasSandgren/C004andCamSync/
(Will downgrade to 1.1.78 temporarily).
We tested 1.1.88 (and 1.1.90) on bench with C004 + cam sync config.
- found NO misfire or mistimed ignition. We even turned RPM down to 63 RPM and RPM detection and ignition was OK.
- note: during initial sync it required one completely good period with no extra pulses. After that it tolerated some noise, eg. double camsync pulse (as long as the offending pulse came in the same 180 degree window between the same too primary trigger pulses).
- when we disturbed the trigger signal both 1.1.88 and 1.1.90 recovered normally after the signal recovered
- triggerlog will need to be recaptured with the new firmware as instructed privately. This will also log the ignition events in the same file with triggerlog input events.
- On bench this worked wonderfully (and re-confirmed the earlier results).
What can be different on bench and on real engine ?
- Maybe something about the camsync position vs configured min/max values ?
- maybe something around the outputs ? Like a relay not powering some coils / injectors ?
- even without this, if the signal is good, RPM detection should work
- another possible reason: output => inputtrigger interference
- also disconnect wideband
Question to developers:
- how did the c004 initial sync became stricter (to defeat bogus spark and backfire with uncertain/wrong signal) after 1.1.79 that, for certain input patterns results in RPM=0 ?
- IIRC new firmware requires 2 camsync pulses with exactly 4 primtrig in between ? Needs checking