Hi guys, I have a Stealth Ram on a 327 with a MAF setup. I am running closed loop with very satisfactory results, except that the BLM's max out at idle and the idle smells unbeliveably rich (it always smelled this way carb'ed too). The cam is an Isky 280HL with 232@0.05 duration and .485" lift on a 108 LSA. I always saw that the O2 NB readings were very very low at idle (almost zero sometimes, but usually in the low 100s), most likely due to the large amount of overlap idling. Above idle the 02 readings and BLM values are normal. I tried lowering the O2 swing values (upper and lower bounds and the swing point) in my 6E. This did noticeably change the idle, not in a bad way, but free revving the car it would have a lean hesitation (5 speed manual trans). I have mostly stock AE values and never had any noticeable tip in problems before when the idle was super fat rich. Is it possible the over rich idle was carrying over into tip-in transitions and masking otherwise too-lean AE settings? I know the large plenum volume of the stealth ram should dictate much richer AE than stock, but I didn't notice this tendency until I just started leaning out the idle by adjusting the low rpm O2 swing values to reflect the low NB O2 readings at idle. Now that I need to richen up AE (it doesn't seem bad driving, I will have to monitor the INT values though), where should I start? I have 6E, and thus 5 AE tables.

 

Definitely a rich engine can shadow AE. Heck, running at 11's can require almost no AE (but 11's on a WB could be 10's, who knows).

Have you tried cranking up the idle timing to like 30+ degrees?

 

I am running around 23-24 degrees idling. I have not tried tons of timing idling, my timing curve would be quite weird with this much in at idle, no? I am going to have to tune AE as I lean the idle out, that should prove satisfactory -- I was just surprised that the over rich idle was actually making the engine require less AE (I guess that shouldn't be that much of a surprise). Now I have to figure out what to do with the 5 AE tables in 6E to correct the leanness I'm seeing.

 

with a 108 lsa on a 230@50 cam you have close to 35degree of overlap. thats the fuely smeel at idle. i doubt the chamber is nearly as rich as you think. would be surprised if the a/f wasnt much richer then the wideband indicates. lots of overlap will make for a tempemental stink engine.