Running Rich

[iliketocrash]

I have the Apex'I Multichecker and according to it i'm getting about a 7 a/f ratio under boost. Could i be running this rich because i have 450s and no fuel management? or are 450s not a big enough step up to cause me to run this rich? so then what could be my problem here?

[r34 gtr]

you need something to lean out those 450s unless you are making enough boost to use all the fuel. maybe your o2 sensor is bad, causing the ecu to run rich as shiznit under boost to protect the engine? the o2 sensor thing happened to me, got the same problem. i was running a 6 to 7 a/f ratio. make sure the o2 sensor is getting the correct voltage too, it was the cause of my o2 problems (as well as the sensor itself, the tip of it kinda broke off and got lodged in the cat).

by the way, how do you like that multi checker? i wanted to get one but never really knew if it was worth it. they dont cost too much if i remember correctly.

- tim

[iliketocrash]

yeah. it was pretty cheap. i forget how much i spent on it but i think it was well worth it. a lot of useful info. but from what you say i think maybe my o2 is bad. it does read about 12-13 at idle though. would a broken one still read that?

[r34 gtr]

yeah. mine ran 13.5 at idle, then plummeted to 6 until about 6.5k, when it slowly tried to climb back. only made it to about 10:1 though..

- tim

[iliketocrash]

you mean just sitting at idle or after you took it for a run?

[r34 gtr]

when i ran it on the dyno. sitting there it was running 13.5.

- tim

[iliketocrash]

well what are some good/safe numbers i should shoot for? idle, boost, and no boost.

[r34 gtr]

uuum, usually 14, +/- .5 i guess would be safe for idle, 11.5-13 across the board on boost, no boost maybe 14-14.5? thats just a guestimate. i would ask dee about those a/f ratios as he knows alot more than i do. tuning wise, im kinda mentally challenged (ryan knows what i mean!)

- tim

[euroboy]

actually except to run rch because the ecu think you have the sock injectors.So the same pulse on these injector will spit more fuel into the engine. You need an safc type of think or a chip programmed for those injetors otherwise you have fuel but it's going to waste

[iliketocrash]

i'm aware that i need an afc. i ordered one and it should actually be here in about a week. i was just wondering if the combination of a busted o2 sensor and 450 injectors with no management would cause me to run so rediculously rich, because i was told by some people that 450s alone shouldn't be such a big step up as to make me get a 6-7 a/f ratio under boost.

[r34 gtr]

well, if i could run that with stock injectors and a busted o2 sensor, im surprised you arent richer!

- tim