I have been slowly but surely getting things dialed in on my MSII 3.0, running MSExtra 1.0.2. I'm usning BDC's extended port timing map for a base timing map for now, and used the VE calculator for a base VE map. I have the VE map running well for driving around town, and have been dialing in the accel enrichment. So far, so good, everything is running well.

I have been encountering a new issue now, I have been running up a little higher on the load to get the VE map dialed in for boost. I have been rolling into the throttle in second gear building about two psi at 4k rpm on the stock turbo and letting off to analyze the log. After boosting, the car runs like crap. The idle is very unstable and any time I push in the throttle lightly the car dies. If the car is still rolling, it bucks hard when I push in the throttle and then runs fine.

It really sounds like an accel enrichment issue, and I can add accel enrichment to make the problem less-worse, adding about 5ms across makes it better. Now, if I turn the ecu off and restart the car the issue goes away, the car idles and drives normally. Now, the accel enrichment is too rich and the car bogs when I shift, so I return the accel enrichment values to where I had them before. The car will drive perfectly fine until I go into boost into second gear and the issue starts all over.

Anyone had this problem before or does my tuning just suck?

 

I've never seen this problem. Could you provide an msq and a datalog?

Thanks,

Ken

 

I'll post them up when I get home from work.

 

Looks like I found the problem. For some reason, I guess I have the hysteresis set too close on the injector staging pressure and RPM, after a little boost the secondaries stay on.

The first value I have the secondary injectors triggered by MAP.

Threshold 105kpa
Hysteresis 100kpa

Second value RPM

Threshold 3800rpm
Hysteresis 3700rpm

Do these look OK? I thought I had the secondary separation at rpm set to 3800/3500. The odd thing is that I have the staging logic set to AND, but secondaries come on below 3800. Not a big deal if they do come on below my RPM threshold, but I would like them to turn off when they're not needed.

 

no, the hysteresis is not the off point, it's how far you have to get from the on-point before things will turn back off...

So the MAP one should be 105kpa and 5 kpa to make it turn back off at 100 kpa, and the second one should be 3800 rpms with a hysteresis of 100 rpms.

Both of these are a bit small on the hysteresis though, so I'd suggest a threshold of 110 kpa with a hysteresis of 10 kpa, and an on point of 3800 rpms with a hysteresis of 200-300 rpms.

Ken

 

I'll make the corrections. Thanks!