Air fuel ratio too lean

clanbuster

Known Member
Senior Member
Jul 2, 2009
55
0
1,506
Used to be 11.5:1
After changed to Rising rate fuel regulator, dislike the setting.
Change back to old regulator.
Also change setting on boost controller to weaken the boost due to overboost.

But All the sudden, found that when boost 0.6 bar, air fuel more then 18:1.

no leak of fuel at regulator.
No leak of sound of vaccum hose.
fuel gauge from 50 PSI , now changed to 60 PSI, still more then A/F 18:1

I guess nothing else i had done recently beside above mention.
Any other reason cause it?
 

Turborized

Known Member
Senior Member
Jun 10, 2010
138
19
518
Kuala Lumpur
Might be due to your original ecu, because usually ecu adapts to your normal mods after few hours or days, so it might not be normal for the engine yet. This is just an exprience i have from putting SAFC I, tuning my fuel flow and boost made my car worst and have to re-tune the whole car. it might be that or something else, im just a newbie with my 2cents. :biggrin:
 

xtremeleo

3,000 RPM
Senior Member
Oct 18, 2005
3,247
464
5,183
what sensor was used to check dis afr? wide band? narrow band?

---------- Post added at 04:17 PM ---------- 6 hour anti-bump limit - Previous post was at 04:16 PM ----------

ohh, and what is ur fuel pressure now? what was the pressure when the apfr was still in ur engine? y did u replaced the afpr? if it wasnt leaking, den its a matter of adjustment jer
 

clanbuster

Known Member
Senior Member
Thread starter
Jul 2, 2009
55
0
1,506
Hi , I using Honda fit l15a engine. Using wide band af gauge. Found the problem due to greddy boost controller. When switch off , back to normal , if switch on, problem a/f back.
Why boost controller affect a/f even setting at same max boost.
2) who knows how to set probecB boost controller?