Differen managment on 1.5 SOHC

MMamdouh · Post by **MMamdouh** » Mon Jun 19, 2006 1:58 pm

i have noticed that their are two different engine managment for the 1.5 SOHC engine that comes on a Lanos.

the first one is the standard issue managment where you got an O2 sensor in the exhaust mani and an EGR valve at the mid of the intake many:

the other one doesn't have an O2 sensor nor an EGR valve... you can clearly identfy it when you see the EGR missing, i has got this kinda variable resistance called "potentiometer" at the firewall beside the coolant reservoir and my mechanic says that this device is used to adjust the mixture:

now how does the ECU manage the mixture ratio if it can't see how rich/lean the mixture is due to the lack of O2 sensor? will making a one fixed setting using this potentiometer be enough to function effecently throuout all the operating conditions of the engine?

also this will mean that the ECU on the first version is different than the other... right? it is already missing the O2 sensor and EGR and god knows what else and it is getting feedback from a potentiomenter that got to fit into the equation.

which system is better? i see that the second one only came out on some Lanoses with 1.5 SOHC... all the other engines doesn't have this alternative managment so that makes you wonder about how effecent it is.

now how about turboing a non O2 sensor engine... will an adjustment to the potentiometer to a rich setting or so make up for the need of a fuel managment device? how would you get feedback about how lean/rich you are running without an O2 sentor to tap in an air/fuel ratio menter??

this managment system is strange and i got to know more about it so if anyone of you guys got more info on it please share.

MMamdouh

MMamdouh · Post by **MMamdouh** » Wed Jun 21, 2006 8:29 am

24 views, not a single reply... the dissapointment is sky high

MMamdouh

Brian5475E · Post by **Brian5475E** » Wed Jun 21, 2006 11:30 am

all fuel injected cars have a O2 sensor, otherwise it couldn't regulate A/F ratio at different RPM'S and loads

MMamdouh · Post by **MMamdouh** » Wed Jun 21, 2006 11:53 am

thats what i am saying... that other engine - with the potentiometer thingy - is fuel injected and has no O2 sensor, how the hell does the ECU manage the A/F ratio??

MMamdouh

Daniel · Post by **Daniel** » Wed Jun 21, 2006 12:26 pm

Hi Mohamed,

Don't be so diapointed. Took time to find a answer

.

This come from Lanos service manual.
Since this car is intended to run on leaded fuel I think to EGR concept was not that important

.
Hope it helps.

Daniel

MMamdouh · Post by **MMamdouh** » Wed Jun 21, 2006 1:30 pm

it helps very much indeed man, now for the performance side of things:

will this managment system be more effecent/powerful than the standard issue O2 sensor controled one? so far the lanoses that came accross me with the "unleaded managment" were too damn fast for the "O2 managment" cars... feels like they got more torque than the O2 sensor cars.

is this a fact or is it just my imagination??

MMamdouh

lanowoo · Post by **lanowoo** » Wed Jun 21, 2006 1:37 pm

i don' know, just seems like its faster and more efficient. and if it is, i wonder if i could change mine to that kinda setup ,if it could work on a 1.6.

MMamdouh · Post by **MMamdouh** » Wed Jun 21, 2006 1:49 pm

the two "unleaded managment" cars i saw were Zikas' lanos and Ehamy's lanos.

i raced Zikas with my "O2 contorled" lanos and he won... i tried his car in a rerun for the race and i won driving his car... i can really feel that his car got more torque with no mods whatsoever, mine is slightly modded but it got heavy wheels and i think my clutch is not that good too so this could be it.

Elhamy raced Ayman - "O2 sensor" contoled - and Elhamy won so thats unleaded 2 - O2 sensor 0, not sure if this is related to the managment or not... maybe if i driven Ayman's car and raced one of them leaded managment car to really see the difference.

as for swaping into an unleaded managment, i think it will be hard... the least thing is swapping in an ECU and engine harness, CO adjuster and God knows what else not to mention that we still not sure if it is really effecent or not.

MMamdouh

Post by **Efratech** » Wed Jun 21, 2006 1:57 pm

Zikas had a 2.0 at the time?

if so, there u had the difference.

anyways... for what you have said... it seems that the other management is less restrictive.

As far the 'swaping' thingy to be honest i dont think is worth the hassle.

MMamdouh · Post by **MMamdouh** » Wed Jun 21, 2006 2:02 pm

Efrain A. wrote:Zikas had a 2.0 at the time?

if so, there u had the difference.

Zikas got 2 cars:

2.0 Turboed Nubira - will never even think of racing that machine.

1.5 Lanos 100% stock... thats what i raced and thought i'd beat hands down.

MMamdouh

ubuyau · Post by **ubuyau** » Fri Jun 23, 2006 10:39 am

Looks like there is one more setup where you have an O2 sensor in the Exhuast Manifold but no EGR valve. Wire goes down to the Exhaust Manifold sensor, but no EGR Valve.

I would imagine that the setup with the O2 sensor would be better since mixture adjustment would be done quicker by ECU making the adjustment "real time" based on sensor reading.

Also the setup with EGR valve would have slightly less power too i think. The recirculation of the exhaust gas in the intake would lower the combustability of the air being sucked into the engine. Sure it'd run more "efficiently" since its running leaner, but who wants efficiency when you can have power!

I dont know about using the potentiometer to tune. I GUESS the ECU must use the setting of the potentiometer as a sort of variable multiplier to a mixture matrix stored in the ECU - thats the only way i can think it'd work - but im guessing...

As for checking AFR - You'd need a Wideband Air Fuel Meter to check the mixture if there is no O2 sensor to get a "Skinnyband" air fuel ratio measurement... You can get ones that you stick up the tip of your exhaust

They're expensive, but some workshops will have wideband sensors and they give a WAY more accurate indication of mixture over the skinnyband O2 sensor air fuel meter.

--Tim

chronoti · Post by **chronoti** » Fri Jun 23, 2006 2:21 pm

lack of egr wount matter at WOT it shuts off and no exhaust gets in.

you wount want to use the leaded ecu because it would use a diffrent timing map.

but the advantage is you turn a screw and you can increase or lower your a/f

but that can be still achived by a piggy back like the smt or an adjustable o2 sim.

MMamdouh · Post by **MMamdouh** » Fri Jun 23, 2006 3:07 pm

then the EGR and O2 sensor are not related in this setup... it is just a coincedence.

MMamdouh

MMamdouh · Post by **MMamdouh** » Tue Nov 13, 2007 3:01 pm

BUMP... what if i wanted to turbo the 1.5 with no O2 sensor... how would the ECU calibrate the A/F ratio in responce to boost?

i know i need at least RRFPR or piggy back but still the ECU detects that the engine is running a bit lean and adds up more fuel... how can O2 less engine achive that??

MMamdouh

MMamdouh · Post by **MMamdouh** » Thu Nov 15, 2007 1:27 pm

anyone?

MMamdouh