i was wondering how you would go about richening the a/f ratio using tunercat? i need to richen it all around at normal operating temps. I'm running the plugs white right now after switching to ngk tr-55's (mods in sig) so i need to richen it up so i can drive it around without consequences until i can get to my dyno tune later this month.
also, can i ahieve this by changing the fuel injector flow rates? if i can, would i just raise it and leave it at that?

 

If it is lean in all cells you can lower the injector constant to richen. Lowering the number makes the pcm think it has a smaller injector so it adds fuel to compensate. The other option is the maf tables for finer tuning. It works opposite the injector constant.

 

If it reall is running lean under normal driving conditions, in closed loop, then you have another problem because the computer thinks it's maintaining a 14.7:1 ratio. You can't change that for closed loop & non-PE operation.

 

all i know is that i am running a tad lean as indicated by the spark plugs...since most of my driving is daily commute and 1/4-1/2 throttle driving, i'm not blaming it on WOT.

 

Taging Thread

 

All plugs look the same? No difference between cylinders or banks?

 

very little difference. ranging anywhere from an off white color to a very very light tan. With the NGK Tr-6's, i was getting a good tan color, but i don't need tr6's for 11:1 compression and no nitrous. it definately has more ***** now after i chaged the plugs and wires. i just need to get the mixture good enough to get me to the dyno tune session. I changed the injector rates so hopefully that will be good enough.

 

Have you checked your BLM's? This will tell you what the car is doing during non-WOT situations. If it is pegged at 160 (lean), then there is something wrong with something besides the computer. Did you have the injector constant correct? You could up the fuel pressure too if you have an afpr. That would do pretty much the same as lowering the injector constant, but the computer should compensate for it and make the car run a 14.7 a/f anyways. Make sure the O2's aren't bad.

 

If youre worried its to lean for now and going to the dyno soon, just do like he said above. Up the fuel pressure or lower in the injector constant. If your plugs are still a little tan I would say you are fine till you get it tuned.

 

i don't even know what blm's. are. lol if my O2's are bad, wouldn't i get a code for it?

 

They can be bad without throwing the dtc. How are you using tunercat without some kind of scanning software? That would be the best thing to do is get it scanned and see if your getting knock from the lean condition(if the blms show it lean). If theres no knock or the blms are close to 128, I wouldnt mess with it since your going to the dyno soon anyway.

 

i use tunercat without a data logging system becuase i don't tune the car. i originally got tunercat so i could easily upload tunes provided by mail order tuners. for 90 bucks and a cable, it was worth it. Lately, however, i have had to become involved to try and solve a few things. i plan on getting datamaster

 

Good idea.

 

I second this.

I would get some better data on what your mixture/fuel trims actually are than just the shade of your spark plugs.

 

since my o2's are original and have had antifreeze on them, i went ahead and ordered new ones from gm parts direct. hopefully this will make a difference.