Insanely High 4AFE Fuel Consumption

[Veloc]

Haha .. waiting for my feedback ahh .. Ok just be honest, my fc has not improved at all LOL !!! My o2 sensor i think rosak for few years already .. i just got this car since last year. When 2 of my sisters drive this car, they dont give a damn about this car. Girls mah .. duno how to appreciate cars. Now I only know the problem of this car. I think my dad wasted more than RM3000 worth of petrol already ... he always say that this car is a 2.0liter car, somemore 19 years old already .. high fuel consumption is normal .. I told him that it could be O2 sensor problem .. he just wouldnt listens to me ... because I told him O2 sensor could cost a few hundred.. I'M DARN ANGRY !!! My dad is mmg like that .. his toyota unser's engine oil kosong until one drip also no more already he still dare to drive for about 3 weeks .. then complain about the car losing power WTF !!! When I check for him, I'm shocked .. I told him that engine oil no more, he say nvrmind la inside the engine got reserve tank !!!!!!!! THEN DRIVE SOMEMORE CB !!

Maybe dads are like that Lol... Same here... My dad drive a trooper last time... The mechanic advised him to change the turbo. When I tested, I said the turbo is not suitable as it is for bigger cc cars. It start boosting around 2.4k rpm and that is damn late for a diesel car. The previous ori turbo start boost around 2k rpm and by 2.5k, can get 10 psi... Great FC and power.... After change become underpower... but He didn't listen until one day, He realise what I said is true... Zzz...

---------- Post added at 01:58 PM ---------- 6 hour anti-bump limit - Previous post was at 01:55 PM ----------

Since it got the standard reading, give the ECU some time for it to re-learn itself.. :)

Still no feedback from xMika..maybe he's happy dy? heheh..

How to relearn? These standard ECUs are non-programmable. They already have set settings. Now I don't know why the FC still same. Since got reading form the sensor, the FC should be better... Gonna check if got any leaks in the exhaust manifold... In case got fresh air get in and f*** up the reading...

 

[Veloc]

I think I've found one of the reason why my car is so thirsty... Will try to fix it soon... ^^

 

[xMika]

Why why ? Please share .. I think of of my problem of high FC is due to Shell's RON95 petrol LOL .. I'm switching to Caltex for my next few tanks to check out the FC :)

Btw, Corona ST171 with 3SFE engine has programmable ECU which can adjust itself or its settings is standard and cannot be changed ?

 

[muzhaffar]

How to relearn? These standard ECUs are non-programmable. They already have set settings. Now I don't know why the FC still same. Since got reading form the sensor, the FC should be better... Gonna check if got any leaks in the exhaust manifold... In case got fresh air get in and f*** up the reading...

some of the ecu got fuzzy logic function which learn on how you drive..
if you always step on the accelerator pedal, it would learn from it and revice the setting according to how you drive it.the setting is not 100% fix.it will readjust to match with our driving style. that's why afc didn't working well in 20v ecu(maybe to other toyota ecu as well). because it will revert back to the predetermined default setting

just my 10 sen

 

[xMika]

Maybe we should try using greddy emanage and see if theres any improvement ..

 

[Alvsaurus]

Im using Ae111 4afe manual Ron95 Shell Rm30 = 190-200km city driving and abit of highway

 

[levin818]

Veloc,
I think you have a faulty ECU... suggest you give it a check asap before it stall your car somewhere!
I have handled more than 20 units of AE111's ECU (89661-1A340). It is, already in the "waiting list".

 

[xMika]

Eh, my 3SFE also full tank RON95, RM80 for 330km only :( ECU problem also ?

 

[levin818]

Eh, my 3SFE also full tank RON95, RM80 for 330km only :( ECU problem also ?

If the year make is between '91~'96, then chances is very high.
Checking the ECU in the earlier stage will be able to save your from spending unnecessary money.

 

[Veloc]

Veloc,
I think you have a faulty ECU... suggest you give it a check asap before it stall your car somewhere!
I have handled more than 20 units of AE111's ECU (89661-1A340). It is, already in the "waiting list".

Check? How to check ECU?

---------- Post added at 09:35 AM ---------- 6 hour anti-bump limit - Previous post was at 09:34 AM ----------

Eh, my 3SFE also full tank RON95, RM80 for 330km only :( ECU problem also ?

Hmm... 2.0 normally higher FC.. But yours also a bit too high... 3SFE in what body?

---------- Post added at 02:41 PM ---------- 6 hour anti-bump limit - Previous post was at 09:35 AM ----------

I've asked 3 halfcut shops today... Too expensive!!!

Desbil (lanc person serve me): Gearbox=RM850; ECU=450
Tilija (Sabah biggest, cheapest, friendliest chop shop): Gearbox=RM1.2k; ECU=RM250 but no stock
Indah Jadi (No comment... Haiz...): Gearbox=NO MANUAL!!!; ECU=RM500

I better ad in mudah if there's anyone who wants to swap their manual with auto... =.=

---------- Post added at 02:49 PM ---------- 6 hour anti-bump limit - Previous post was at 02:41 PM ----------

Veloc,
I think you have a faulty ECU... suggest you give it a check asap before it stall your car somewhere!
I have handled more than 20 units of AE111's ECU (89661-1A340). It is, already in the "waiting list".

Boss... How to check ECU? Most auto-electrical places here are noobs. They use a multimeter or voltmeter to check if got reading. So they might check one port and if got reading, they say its okay... They may neglect other ports. And ECU not cheap... Today I asked UMW PJ, ECU cost RM 3,830.00!!!! If really ECU, I don't mind spend RM500 and get a used one... But many people all along told me it's this and its that... But after I changed, same thing... I just replaced the O2 sensor... So can you please advice me more on ECU?

1. What are the possibilities that it is spoiled? Is it a lot of cases?
2. If really ECU, can it be repaired (eg. replacing, resistor, capacitors etc.) instead of changing the
whole thing?
3. What other problems may arise from a faulty ECU besides high FC? Anything dangerous?

And... I neglected the fact that my car is using a straight flow muffler. Could this be the problem? But the catalytic converter and middle muffler are still in place.

Thank you!

 

[wfhan]

Eh, my 3SFE also full tank RON95, RM80 for 330km only :( ECU problem also ?

on my case, 3SGE, rm80 of ron97, i'm getting ~400km average

 

[lkeong88]

You need to open up the ECU to check if there are any leaking transistor or capacitor. Levin818 can repair ECUs. His pricing is reasonable

 

[Veloc]

You need to open up the ECU to check if there are any leaking transistor or capacitor. Levin818 can repair ECUs. His pricing is reasonable

I'd be happy to... But too bad lerr... I am in Sabah... Haiz... Hard to find competent guys to check and fix cars here especially those relating to Automotive Technology. Sometimes they ask me back. When I find that I am teaching them back, I will stop going to their place...

 

[lkeong88]

You can always post your ECU to him. He does trade in services

 

[levin818]

Tks lkeong!

Hi Veloc,
Straight flow muffler does increase the FC on the auto tranny. I experience it on my silvertop engine few yrs ago. But for safe, i would suggest the following:
1) service throttle body, check air filter and s/plug
2) check ECU (see below)
3) change back to stock muffler

*How to check the ECU*
Warning: Do not attempt to do this if you are not a hands on person
1) Turn off your engine
2) Remove EFI fuse (15A) and wait for 10 mins for the ECU to completely discharge
3) Pressing the connectors and carefully pull out the ECU - becareful not to pull off the connector's wires. There are total 3 connectors that need to handle
4) DO NOT touch the ECU's pin
5) Open up the ECU's top cover (DO NOT touch the components) and inspect the board conditions
6) If there are a black stain mark around the capacitors, you have a faulty ECU. Replace the ECU ASAP as it may stall your engine ANYTIME!

 

[levin818]

Black stain mark at NG ECU.

 

[Veloc]

Tks lkeong!

Hi Veloc,
Straight flow muffler does increase the FC on the auto tranny. I experience it on my silvertop engine few yrs ago. But for safe, i would suggest the following:
1) service throttle body, check air filter and s/plug
2) check ECU (see below)
3) change back to stock muffler

*How to check the ECU*
Warning: Do not attempt to do this if you are not a hands on person
1) Turn off your engine
2) Remove EFI fuse (15A) and wait for 10 mins for the ECU to completely discharge
3) Pressing the connectors and carefully pull out the ECU - becareful not to pull off the connector's wires. There are total 3 connectors that need to handle
4) DO NOT touch the ECU's pin
5) Open up the ECU's top cover (DO NOT touch the components) and inspect the board conditions
6) If there are a black stain mark around the capacitors, you have a faulty ECU. Replace the ECU ASAP as it may stall your engine ANYTIME!

Walau eh!!! Thank you sifu! So informative... Haha... Okay I'll check and see if there is anything like that. And btw, why did you say that straight flow muffler increases FC on auto tranny? How about manual tranny? and I know they do increase the FC. But is it that much until this extent? 400km become 330km?

 

[levin818]

Straight flow muffler's is not design to improve the FC. It is design to resonant at high rev (ie: >5000rpm), and only benifit for high revving engine with aggressive mod.
4A-FE engine, especially fitted with auto tranny, need the torque at low rev. Original muffler is design to match with the engine power band for maximum efficiency. If you swap in a straight flow muffler, you are actually killing the torque at low rev, and ended up in the drop in efficiency and increase in FC.
How much it increase? Sorry I lost my records so can't comment on it.

 

[xMika]

Oh ya, where is the ECU located ? I know where is the fuse box but not the ECU. my 3SFE is in Corona ST171, year 1991.

 

[Veloc]

Straight flow muffler's is not design to improve the FC. It is design to resonant at high rev (ie: >5000rpm), and only benifit for high revving engine with aggressive mod.
4A-FE engine, especially fitted with auto tranny, need the torque at low rev. Original muffler is design to match with the engine power band for maximum efficiency. If you swap in a straight flow muffler, you are actually killing the torque at low rev, and ended up in the drop in efficiency and increase in FC.
How much it increase? Sorry I lost my records so can't comment on it.

Now that you've mentioned, I think yes. Honestly speaking, my car's low-end torque damn weak for a 1.6 4AFE. I have tried other 4AFE and the bottom end pull is strong. For my car, like cannot move. But when pass 4.5k rpms, the engine start to pull strong. One time when I was pulling out of a corner, the engine pass 4.5k rpm while I was turning and I almost lost ctrl =.=. But only can feel the pull at the first gear la... Above first gear, the sudden pull is not so obvious.

I have checked the price. Ori muffler is RM700++ WTF. I'm going for the AE111 compatible around RM160. Should be okay also right? Stock S-flow.

And another things I wanted to ask Levin818... why does a car needs back pressure in the exhaust for low-end torque? I know free flow benefits high-end power. But why does it harm low-end torque? Before this I thought no effect on low-end. But many say it reduce....