Lean off boost
Turbo Mini Forums

Just got my car driving properly but it's lean when off boost, feels like the timing is to advanced and is really sluggish

But when on boost it runs lovely

Just down to needle?

What are you calling lean ?

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

What are your Afrs?
Lean on over run?
Lean on cruise?
Lean on load / off boost?
Lean on idle?

How do you feel the timing is too advanced?

How long ago since you had your needle profiled / what needle is in there ifnit is stock?

How hot was the fuel?

Got enough carb damper oil?

Has a hose split?

Did you block the part throttle lean off pipe?

Yes i moved to the darkside

Instagram @jdm_brett

We'll it is on its first run

Only around the block and back

It goes right off the scale on the afr


The needle is the standard metro turbo needle


Was up to running temps

Is the part throttle lean off on the carb? Is so that is blocked off

And I feel that's it is too advanced because it has no power at all when off boost, really sluggish then whe on boost it's really nice

It is the actual standard turbo needle or the one that came in the carb you have? I thought I had a standard needle in mine but it had been changed. Standard Metro Turbo needle was BDD

Also, what ignition are you running? If MegaJolt, what map do you have loaded?

If it is the standard metro turbo needle ( BDD )
Let it idle up to temp set the afrs for idle around 12.5-13 ( i found this the best start point when profiling needles)

Take for another spin, i found the BDD to be a very good needle for off boost driving it was just about right on the minis ive settup, rich at cruise with no lean off though

Yes i moved to the darkside

Instagram @jdm_brett

You'll find its rich on boost, as it needs to be, set the idle right and it's pretty much about there, might need a gnats cock of profiling but not much..

Yeah the needle is the BDD

I'm also running a the nodiz ecu with a mj map from here haha

I've set the afr gauge at idle about 14.7:1 I'll set it so it's a bit more rich next tomorrow, I have been driving wig the cholke out so I guess that does the same thing haha

Are you using a wideband or narrow band?

In the 13's at last!.. Just

It's wide band yeah

right ive driven it more and its miss firing some times and other times its fine

could this be down to something braking down in the ignition?

ive also checked the part throttle lean off and i have a pipe connected between the two take offs, so should i block them both off?

Edited by coopdog on 8th Jul, 2015.

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

The problem is, without actually seeing the car, and feeling/diagnosing it's rather difficult to suggest what to try.

You're stating lean, but with no real numbers or exact driving conditions where it happens, or data of what it's like when it feels ok.

Lean on it's own just means nothing, it could be a faulty wideband for all I know.

You say it feels like timing is too advanced because it is sluggish....that is just not how too far advanced would feel.

Retarded timing would make it feel lethargic and sluggish. But you dont mention how much timing it actually has under any driving conditions.
Improper timing can also give odd symptoms

I dont know what coil, plugs, plug gap etc etc you have, so there could be issues there, but without feeling this miss, again very difficult to suggest a fix that shouldnt already have been checked as per basic setup.

It could be an ignition problem or poor setup/tuning, it could be carb setup, it could be an actual problem with either. Or indeed there is also a chance it could be a mechanical problem.

What has changed from it last running correctly, to it running badly ?

You do mention setting an idle AFR to 14.7:1
I can only imagine that in itself will make things leaner than desirable everywhere. Stioch values might be wonderful in an efi world, you'd never have seen a factory Metro Turbo engine run that lean at idle.

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

Argh. I always suggest that pipe!

In the 13's at last!.. Just