MAF Tuning via Wideband + Injector Adjustments

[BigDaddyCool]

Quick question on maf tuning.

I have a wideband and logged the maf, i've been correcting values that exceed 14.68 with lamba being 1.0 which seems to have helped, now i'm at the stage where maf seems OK but knock still persists and I noticed despite the MAF average reporting under 14.68, eg. highway 2000rpm. I am still getting like 15.4's etc for ATR.

Would I be correct in thinking I now need to focus on injector timing, because if u tune the maf further i've found you loose power and it feels odd when driving etc.

Thoughts? Common concept. This is a 2006 VZ Commodore 3.6ltr V6 alloytech based pos with the crappy bosch ecu.

PS. I want to get this sorted before pulling spark of the stock timing tables.... as I find it just reduces power.

[TGP-37]

I would return to stock first. Then set Closed Loop Enabled to 284°F.

Set Open loop fueling to stoich. If you are pumping E10 which is becoming common, stoich is a little lower. I found 14.35:1 for my fuel.

Scan the car while warming up from a cold start. No throttle, just idle. Once the engine reaches Operating Temps, rev it up some. Let it settle down back to idle and record the idle AFR. You can use the warm up scan to rescale the open loop AFR vs ECT. What ever amount off from stoich it was, reduce that from the desired amount at that specific temp.

If you are lean, lower the injector flow value slightly
If you are rich, increase the injector flow value slightly.

Do this until you idle at stoich. Now your injectors are generally tuned. Some people prefer flow benching them for real numbers.

Remember to change Closed Loop Enabled back to the desired temp.

Now the stock MAF Table Curve should be very close to accurate. But you will want to tweak the curve. Here you can take this as far as your imagination can create. I've used excel to calculate some detailed analysis of logs to tune the MAF Table even tighter.