crank trigger issues with ls1 - ls2 sensors Link Thunder

[Anguscrx]

Hi there

We have had an ls1 running for 2 seasons no issues. well apart fro a bent rod end of last season.. that aside

we have swapped out to stroker ls2. Crank came with a 24x wheel

engine loom has stayed the same. so 12v feed to both crank and cam.

Crank is 24x the dual style wheel.. sensor is the ls1 sensor 12v feed.

Cam is a 4x with a ls2 sensor (requires 5v) but is working on 12v (i am going to put this to a 5 volt feed but it seems to work fine) I've done the wire swap to the sensor as the power is switched between ls1 and ls2 sensors. (loom extended)

the engine ran great for 60 seconds with a few trigger errors.

Tried again today to check on the trigger errors and now it runs but for a very short period with some rpm spikes to 20000rpm ign cut takes over and shuts engine down. a fair few trigger errors

I have checked the trigger scope and the crank and cam are falling and rising at almost exactly the same time.

could the voltage reduction help? i don't really want to cut into the loom unless i have to, the wires currently wont stretch for a re-pin. I don't really see how it would but worth an ask... apart from potential sensor failure.

trigger mode ls1 5-10

rpm filtering 1

trig 1 hall

filtering 2

pullup on

edge rising

trig 2 as above

scope attached

Thanks for looking

Trigger Scope Log 2023-05-15 4;22;18 pm.llg

[Anguscrx]

Tried again today and car now runs with no random rpm jumps although still has some crank trigger errors.  as it ran i took a trigger log. 

 I didn't change a thing just a different day.  so ?

 

Thanks

Trigger Scope Log running 2023-05-16 5;18;54 pm.llg

[Anguscrx]

Looking at the trigger scope (set up to rising) the two long 'pulse'  sync points are too close meaning any slight variation is going to throw up a error... ? this is correct right ? 

if that is the case how on earth do i solve that issue ?  its only the two long sets that seem to line up causing the issue the other 2 smaller are fairly close to 50% or good enough.  

I cant win with either falling or rising as on that one cam 'tooth' it traces both almost perfectly.  

[Adamw]

I cant download your scope files for some reason but it sounds like you have a mismatched cam and crank set.  You cant use a 24X crank wheel with the 58X cam pattern, both need to match.  The 24X crank should have a cam level type sync - basically a long single tooth that is high for 360deg, low for 360deg.  

[Anguscrx]

Thanks Adam 

seems that’s the only combination that doesn’t work. If you know you know… 

 

[Adamw]

You have made an ambiguous logic.  The 24X crank wheel has a unique identifier on it every 90degs, so the ecu can determine the crank position as soon as the crank has rotated 90deg, once the ecu knows crank position it just needs to check if the cam is high or low and since the cam only changes state once every 360 deg, it then knows full cycle position so can start right away.  

With your combo the cam level will be wrong for 3 of the 4 possible check positions.