siamese code trial Supercharged Pickup
Turbo Mini Forums

Hi!

I have an issue with the MS siamese code: I can't get the mixture right at closed throttle.

Situation:
Weber inlet manifold
KMS throttle bodies with 1200cc injectors (about 10-15 cm from inlet port)
1 lambda sonde in Y-piece
1 lambda sonde near outlet cyl 4 (temporary, remove after setup injector timing)
Supercharger disconnected from inlet.
Sequential injection timing on, seperate VE tables off.

When I start the engine it runs at about 1500 rpm, a bit high but thats not the problem.
The reading on outer AFR is fine (about 14), but the reading of the 'overall' AFR is way too lean (about 19). I've tried a lot in timing of the injectors, but it doesn't seem to react on that.
When I drive the AFR's are pretty fine, the issue is mostly with closed throttle.

Wich timing table is for outer and wich for inner. If everything would be perfect I assume there must be about 90 degrees difference between the tables?

Does anybody know what I do wrong?

Kind regards,
Remko

Edited by remko on 25th Apr, 2013.

The first table is for cylinder #1. And the timing is with respect to the cylinder being injected so there is no need in principle to have any difference; the code will compute the appropriate timing difference for each cylinder.

Jean

http://www.jbperf.com/

Just to see I understand it right...

With both tables at 0 degrees there is an actual difference of 90 degrees?

Actually the difference is 180 crank degrees since the cylinder are separated by 180 degrees (and 540 degrees). The complete cycle is 720 degrees not 360 degrees.

And if you want the same value for both cylinders you can use a single table. That might be the easiest starting point.

Jean

http://www.jbperf.com/

You're right about the 180 degrees....

Single table gives me the same result.

Can you switch the lambda sensors and the controllers to see if you get the same results?

By the way, what controllers are you using?

http://www.jbperf.com/

I am using 2 identical tech edge controllers with identical lambda-sensors.

I will try to switch them tonight to see if the problem moves. The strange thing is that the mixture gets quit equal with a little bit of throttle.

Another problem is that I can't find by second lambda sensor at the megalog-viewer. Anybody familiar with that? In tunerstudio it's no problem.

Regards,
Remko