Running lean on idle

[Rob]

Hey guys.... me again.

Just a quick one, im using the GA16 injectors (black) but with the Apexi neo im having to put in fuel on idle to get it to run near stoich other wise it does run very lean 17/18

Any ideas?

Rob

 

[frank]

mine runs closed loop at idle rob, maybe a t/p/s or idle screw adjustment needed ?

 

[Rob]

Surely if its running closed loop on idle i shouldnt need to bump up the Apexi readings to put in more fuel? Especially as its got the bigger injectors? If anything i should have to take fuel away?

Ps i may be totally wrong so correct me if i am! haha

 

[Stani1029]

I have the same issue and noddie reckons a small air leak could cause it? I know for a fact the plate covering the maf board isnt fully sealed on my TB.

 

[Rob]

mine runs closed loop at idle rob, maybe a t/p/s or idle screw adjustment needed ?

Just sitting hear thinking... could it be the micra pump isnt man enough for the bigger injectors?

 

[Rob]

I have the same issue and noddie reckons a small air leak could cause it? I know for a fact the plate covering the maf board isnt fully sealed on my TB.

Ive not had the TB apart. Ill recheck the boost hoses but cant hear any air leaks

 

[frank]

a leak would have to be post/downstream of the t/b to affect the idle rob, and my stock pump was supplying SR20 injectors 10:1 a/f/r,s @ 130hp, so it wont be that

 

[Rob]

a leak would have to be post/downstream of the t/b to affect the idle rob, and my stock pump was supplying SR20 injectors 10:1 a/f/r,s @ 130hp, so it wont be that

Strange though isnt it that with the Ga16 injectors fitted its not over fueling on idle with the Neo turned off. If i remember right its almost off the scale lean with the Neo and all fuel corrections turned off.

 

[Rob]

Maybe its worth me trying to get the SR20 fuel rail sealed and fit that with the SR20 injectors and see what that does

 

[frank]

it sounds like you have a leak or sensor issue to me rob, the mot does a natural idle emissions test nowadays iirc (so would need to be closed looping for that).
is yours closed looping @ cruise ?

 

[Rob]

Yeah if im crusing it will fluctuate between 14/15 ish all ok

 

[frank]

Maybe its worth me trying to get the SR20 fuel rail sealed and fit that with the SR20 injectors and see what that does

have you set the idle like it says in haynes ? if the tps is,nt set or the idle control valve is out of its perameters (ie, throttle idle screw too far out)
there,s one of my vids on youtube recently showing me forcing it out of closed loop/lean by opening a leak valve on my dash

 

[Rob]

Since having the micra i havent touched the TPS or idle control valve, would it need adjusting for the turbo conversion?

 

[frank]

Since having the micra i havent touched the TPS or idle control valve, would it need adjusting for the turbo conversion?

changing the injectors mainly affects the idle and low throttle tho eh

 

[Rob]

Good point franky!

suppose i better go buy a haynes manual... unless someone has the procedure written down?

PS. I love you frank, thanks for your help. I owe you a beer or 2 if i see you at a car show!

 

[frank]

basically you remove the tps and blip the thottle a few times, then adjust the plastic allenkey screw on the o/s/r corner iirc

 

[Rob]

So is the allen key a air/fuel mix adjustement screw or just allow more/less air past?

 

[frank]

So is the allen key a air/fuel mix adjustement screw or just allow more/less air past?

it simple bleeds air past the throttle eh, so if the revs are still too high, you need to close the butterfly more

 

[Rob]

Sweet will give it a go

Thanks Frank

 

[Rob]

Found the air leak

it simple bleeds air past the throttle eh, so if the revs are still too high, you need to close the butterfly more

Found the air leak! Found a vacuum hose from front of inlet off!

Adjusted the idle too, the fueling has riched out slightly but still sits about 15 on idle.