This page contains all test of the new Subaru Trigger code
28/5-2010
Did some more test today.
Status car is not running.
All test results will be published Saturday
Scooped signals to the processor and did not find any thing wrong.
Stable rpm until it starts to fire then rpm spikes to 3000 rpm. Symptoms like the old trigger setup.
When the engine starts to run fast it looses sync.
What we have seen 2010-05-24
We have stable 160 rpm at cranking fuel pump off.
When we cranking the car it´s stable in beginning it fires up to 300-600 rpm then random fires and rpm is no longer stable.
Its like it runs only on two cylinders (firing correct) but then losing sync.
We see some correct firing´s but also ignition fires at different times than it should. Obviously there is noise in the signal, that must be filtered.
Question: Haw is this code tested and what signal is used?
- It is very important when testing that we have a swinging signal like 100-300-120-500-200 rpm`s and not lousing sync. Not joust a long stable sweep
- yes, it is tested with sweeping signal
We have big trouble scoping the output of LM1815 because of the short signal like 15 micro sec. It should be a bit higher (20-30 usec), but you can enlarge it very easily, see below.
I would suggests that we use the p259 led´s output. When the processor get signal from lm1815 Pre/sec trigger we set the output high for 0.5 sec. This will give us a chance to see and measure what goes in and out of lm1815.
Triggerlog also shows the time of the pulse (although currently for the primary trigger only).
Watching the input with analog scope is of primary importance. Even if the output is perfect, if the input is on the edge, it can break any time (eg. in cold).
Analog scopeshots ? do you have some ?
http://www.syvecs.com/forum/viewtopic.php?f=6&t=110&p=474&hilit=trigger+pattern+advisory+note#p474
If the input is biased properly, the LM1815 adaptive filtering should filter out small amplitude "phantom-tooth" pulses in the subaru. I didn't see your scope so only you can judge the offending amplitude. 10-30% should not trigg, and with lower R181 / R182 even higher amplitude offenders can be filtered out
Maybe the noise is capacitively injected by ignition ? It could save a LOT of time (even 1 week) to route the VR signals via properly shielded cable (with ground wire inside, and shield connected to ground only on ECU side). Than only try the factory harness when it works well with the separate shielded cable so you have a good starting point reference.
Ideas - setting up more agressive filtering for this low toothcount
- the LM1815 (especially for the primary trigger) is set up so it can receive 9000 RPM signal from the audi 135 tooth. As subaru has only 6 teeth (the shortest gap is 30 degrees which is equivalent to 12 teeth) the circuit can be modified for 10 times higher times.
- 10 nF => 100 nF on the input
- 1nF => 10 nF for the output pulse timing
- please verify the above values (I wrote them from memory), and multiply with the accompanying resistor so 3*R*C is less than 30 degrees
- LM1815 mode pin5=5 can be tried (and left it open can be tried too). Often used with 1k pulldown in audis for the low toothcount crankhome-VR.
New Vems pcb installed
Our technical engineer trying to hunt down the errors
Test car 600 Hp HKS Subaru