closed loop

140dB · 02-07-2006, 02:55 AM

me chassis : satria y2k
me engine : 4g13 year 2k efi mitsu ecu
me mods : cai and pz camshaft

me just fits me an afr meter.

me sees the meter go rich-lean-rich lean during idle

even w/o the a/c on

is it normal

rpw website sez they dun recommend cams w/o ems tuning

i bet the cam is messing me map signal during idle..

another funny thing:

during cruise, afr also goes rich-lean..dis i suppose is close loop working...

btw, my ecu pin out is similar to evo 1-3

cept that im running map, disty etc.. etc....

any sifus wanna share whats really goin on?

TIA,
140dB

Battousai · 02-07-2006, 10:32 AM

Don't worry, your car is fine. The AFR starts 'scanning' because in closed loop operation, your ECU is continuously adjusting your fuelling to get the optimum mix which is 14.7 AFR. Since the ECU is adjusting many times per second, your AFR meter seems to move erratically.

Nothing's wrong with ur cams either, because since ur ECU is in closed loop operation, it's still able to compensate for your fatter cams. Of course, tuning with a piggyback ECU or EMS will significantly improve your power.

EFN · 02-07-2006, 11:23 AM

Yup, most AFR meter are using the OEM O2 Sensor which is a Narrow Band type - so when in Closed Loop operation it will "dance" around like mad and very hard to tell the actual reading. But if you use Wide Band sensor like the ones Battousai have, you can get accurate reading.

140dB · 02-09-2006, 12:55 AM

thanks guys for reconfirming mah thoughts..

yes, i plugged my afr meter to stock 02, so i guess my reading range is very limited to say 12-15 or maybe narrower...

1 question, since i'm running closed loop, would "interceptor" type piggy like safc really help? unless i intercept my 02 signal as well right?

emanage injector harness connects directly to injectors (according to manual-adds duty cycle directly to injectors)...but i'm afraid to do that as mitsu uses low imp injectors right? fraid i might fry my emanage....

anybody tried it on theirs? or maybe i can try putting resistors...who knows how to calculate the correct value?

TIA for ur thoughts..

140dB

Battousai · 02-09-2006, 01:51 AM

you will need to add a capacitor in series, not a resistor. Not sure abt the value...

140dB · 02-09-2006, 10:39 PM

yo battousai,

are u sure its supposed to be a cap?

cos afaik, the waveform for injectors is usually square wave..
adding a cap will only distort the waveform to a sawtooth.
peak current will remain almost same as w/o cap....altough for a much shorter period...there is still chances of frying my emanage...:Not_Impressed:

sound quite workable anyways....but i dont think i'll take the chance...just not yet la anyways

140dB

Battousai · 02-09-2006, 11:24 PM

sorry i misread ur post.
you're right, shud be resistors.

dagger · 02-10-2006, 07:58 PM

it won't fry your emanage, but will give inaccurate readings on the program readouts, and give wrong signals to your injectors... causing the usual CEL.

As for using the right resistors to step up the signals for the low impedence injectors to high... do let me know man... i would really need that too! I was thinking if we can use the resistors to step down the value given out by the emanage to the injectors... since the ecu also gives signals in low imp.....

hope i'm not confusing you dude....

eater_eg6 · 02-12-2006, 01:45 PM

sifus , what mean close-loop ??? :) soli .. newbie question.. :)

140dB · 02-14-2006, 12:12 PM

Quote:

Originally Posted by eater_eg6

sifus , what mean close-loop ??? :) soli .. newbie question.. :)

hi eater,

closed loop means ur ecu takes input from ur oxy sensor to increase/decrease ur fuel...

btw, ur oxy sensor measures exhaust gas air fuel ratio. hope this helps

140dB

lozo · 02-17-2006, 09:09 AM

then, during open loop, the oxygen sensor is not taken into count ?

Battousai · 02-17-2006, 10:39 AM

Lozo: correct