What is the safest I can lean out my OL tables? On startup the exhaust smell is pretty strong and the wideband reads an afr in the 10s.

I'm moving into a new private garage and don't want the startup exhaust smell to be a problem for the tenants above. I figure if I lean out the OL tables it would smell less.

Do you think if i make the lowest OL afr target 12.5 the car would still start without problems even in cold weather?

 

I will probably start as the prime pulse, added prime pulse and prime pulse crank are all adjusted by coolant temp. However the Open Loop AFR takes over after the engine kicks over. It will be like running and old carb car w/o a choke.. may stall or run rough.. never tried it so I can't really answer you question.. Do you have air and Cat operational Air pump gets rid of rich exhaust after starting, Cat really doesn't work when cold but it tends to filter out some of the raw exhaust smell. I have both deleted and true it stinks up the garage pretty bad...

 

yeah all that stuff that helps to prevent my problem is now gone. i now have to try to get around it through tuning. im going to make the lowest value 12.5and see what happens. im hoping GM engineers went towards the overkill side on those OL tables and the adjustments wont be a problem.

on a seperate note the car sometimes begins to stall or completely stalls out when i put it in reverse. do you know what table can help me fix that?

 

I'll post up my open loop table later tonight. It worked for me every morning down to at least -10F. I spent a lot of time calibrating my maf though and what i commanded was always what I got so your results may vary.

As for the into gear stalling. I have posted some fixes for that previously. Can't remember them right now. One piece of advice I can offer you is don't wait to put it into gear once its started. In other words don't let it settle to programmed idle.

 

Theory here being that if it starts to die, map will drop off and it will richen up and catch itself. Never had any trouble with it. Its leaner than stock but still conservative if you have a decent comp ratio.

 

Put your cat back on or get used to the smell.

 

thanks bro. long time no speak. just got my car back. i'll drop you an email to catch up on things.

 

if i theoretically removed all emissions equipment and put a high flow cat on would that alleviate a greater part of the smell? i'll try tuning first but if that doesn't work i'll have to get one of those high flows.

 

Need the smog pump to get em lit when its cold in theory. They also are really not going to like the kind of crap thats going to come out the exhaust with a decent cam.

 

so are you saying save the 270 and dont buy the high flow cat?

 

Thats right. I'd just learn to live with it, you're just complicating things by adding a cat back to it. Cats have very specific requirements to survive, your engine and controls are not set up to meet that anymore. Is it worth it to burn up a cat or two learning how to make it live? If it fails will you know why and what **** to turn to fix it?

 

I wouldn't think you'd need it. Newer cars don't even have a smog pump and the cats live just fine.

You could probably play with VE also to get the AFR in line.

 

i need to modify my ve tables again definitely (i run sd mode). anyway logged the car for the first time and yes the left side is pig rich. prior tuning was done with a dead cylinder so thats why its super rich. i'll get my ve tables in order and bump up my open loop tables using what ws6t3rror gave me. the log let me know that my right O2 is on the way out so i have to replace that as well since closed loop is running super rich too. all this should help alleviate the smell.

 

That's a problem with cam'ed cars.. I assume with an A4 your at 700 RPM or higher in drive.. do you have your closed TPS timing cranked up, also running the TPS=0% voltage up a little (opening TB plates) to the .65V range helped me. The IAC is not fast enough to react when you shift into gear or reverse, so you only have timing, TB closed position air and fueling to correct stalling. Also try cranking the idle underspeed timing advance Vs RPM up a degree or so. Key is to keep the idle from dropping way low, where you loose MAP and timing, make sure your closed TPS timing at 400 RPM is cranked up so you don't pull timing when you need it, when it's getting ready to stall. As you change any tables to tune your idle watch your MAP, the RPM will not change as the PCM tries to keep it at desired idle if the Kpa goes up the change is not helping you, key is to get your Kpa as low as possible when idling. Once you get it correct then test the transition from idle to TSP>0 when it switches to the main timing table, should be no hesitation nor timing drop as you normally take off from a stop. Seems each car acts differently to changes so what worked for me may not do it for you... good luck

 

good advice, thanks bob.