OhEvoIX

Ok so at idle my afr stays around 13.5-14.7 which is fine. And under boost or while driving it stays between 14.0-14.7, fine as well. But if I'm driving and then put it in neutral while driving and let the rpms drop to idle, sometimes the idle will jump from 1100 to 1500 back and forth and the afr is usually around 11.0-12.7. But as soon as I come to a complete stop it will stay at 1100 and normal afr (between 13.5-14.7). Any idea why the rpms raise and drop ONLY when driving and in neutral and the afr running rich?

MR. EVO MR

iTrader: (9)

If your boosting at 14.7
Something is wrong big time.

evo541

Maybe by saying "under boost" he meant before boost kicks in? I strongly agree that if you are seeing 14-1 AFR under boost you have a major problem and should not be driving it.

OhEvoIX

Please explain!???

OhEvoIX

I thought 14.7 was the optimum point at which fuel is burnt. Not too lean or too rich?

OhEvoIX

Ok just reset my afr and under boost I'd at 12.2. Not 14

OhEvoIX

When I say under, I mean in boost*

evo541

Idle and cruising afrs should be close to 14.7-1, in boost it should taper down to 11-11.8-1 range. You have to run a richer AFR in boost to avoid detonation.

If you provide some more info on your setup and what mods you have we could better help you. Is the car tuned for the mods you have?

OhEvoIX

It is tuned for the mods. Tuned by topspeed in atl. And what you said makes perfect sense. It is tapering down into the low 12's in boost.

Mods

GSC S2 cams, BC springs and titanium retainers, weisco 9:1 .020 pistons, BC rods and crank, fluidampr balancer, ported exhaust manifold with Arashi TD0620G turbo on 24 pounds of boost, MAP divorced o2 dump with turbo XS 3" DP, full 3" exhaust.

OhEvoIX

1650 injectors as well