Fuel Consumption for e34 1jz

[rizal_E34]

Guys,Im sure this is already discussed sometime back..but i dont seemed to find it, so, i start a new one.My e34 1jz fuel consumption is quite high. Full tank would only last me about 350kms, on the hwy!!! Im about 180km and the needle is past half tank in town driving. Is this the draw back of having those 280 hungry horses in the engine bay? Can I do something to make a tankful last a way bit longer? I promise i'll be light on the throttle

 

[seech]

400km for 50 liters. (used to be 300 to 350km per 50 liters before due to a faulty ECU)

 

[-azfar-]

Guys,
Im sure this is already discussed sometime back..but i dont seemed to find it, so, i start a new one.

My e34 1jz fuel consumption is quite high. Full tank would only last me about 350kms, on the hwy!!! Im about 180km and the needle is past half tank in town driving. Is this the draw back of having those 280 hungry horses in the engine bay? Can I do something to make a tankful last a way bit longer? I promise i'll be light on the throttle

rizal - oh my 350kms/80litre on highway? your right leg must be very heavy la:laugh:

seech - your fuel consumptions look very good bro for a 1jz. haha

 

[rtgp]

Rizal, I think your FC is really high. Mine getting about 400-420km for 65liters on city driving but for highway easily can get above 500km, and I understand some of our forummers here are getting much better than mine which I'm really curious how they achieve them:39:. Maybe you can try some piggyback ecu which can tune for better FC and power.

 

[rizal_E34]

hmm yeah.. it really looks bad.

seech, how did u determine that faulty ECU caused the high FC? I was told that the previous owner did repair the ECU due to some idling problems. Could this be the issue?

Im getting really annoyed seeing the fuel gauge drop ever so fast!

 

[seech]

Rizal, I think your FC is really high. Mine getting about 400-420km for 65liters on city driving but for highway easily can get above 500km, and I understand some of our forummers here are getting much better than mine which I'm really curious how they achieve them:39:. Maybe you can try some piggyback ecu which can tune for better FC and power.

I acieved mine by having a lighter right foot.

hmm yeah.. it really looks bad.

seech, how did u determine that faulty ECU caused the high FC? I was told that the previous owner did repair the ECU due to some idling problems. Could this be the issue?

Im getting really annoyed seeing the fuel gauge drop ever so fast!

Actually I did not know the ECU was faulty until I started to have problems. The 1J felt underpowered, lots of black smoke under boost, uneven idle, slight misfire, etc. Basically signs that it was running rich. Fuel consumption gradually got worse from around 350km per 50 liters to 300km.

Thought it was MAP sensor but upon further investigation there was a short on the ECU board. My mechanic sourced for a used one and on the first test drive it was much, much more powerful. No more smoke also and much improved fuel consumption. So far on easy driving in town can get around 400 mm per 50 liters which is about the same as my old M50B20. Good stuff.

 

[rizal_E34]

Actually I did not know the ECU was faulty until I started to have problems. The 1J felt underpowered, lots of black smoke under boost, uneven idle, slight misfire, etc. Basically signs that it was running rich. Fuel consumption gradually got worse from around 350km per 50 liters to 300km.

Thought it was MAP sensor but upon further investigation there was a short on the ECU board. My mechanic sourced for a used one and on the first test drive it was much, much more powerful. No more smoke also and much improved fuel consumption. So far on easy driving in town can get around 400 mm per 50 liters which is about the same as my old M50B20. Good stuff.

the previous owner did hv sm idling probs bt claimed he fixed it. power is ok on mine bt i nvr bn on another 1jz b4.

bro, is ur mech open on sundays? hw much s a used ecu? any difference betwn ecu for manual n auto?

 

[seech]

Hey rizal,

My mech not open on sundays unless he happens to be there completing a project. No real way to determine if your ECU is failing. Just some symptoms. Costs depends as getting a hold of a spare ECU can be difficult so pricing dependent on where you can find it.

Auto and manual different as the auto ECU has additional sockets for the control of the auto gearbox.

One possible way to test is to try out another 1JZ and see if yours feels underpower. If not then your fuel consumption could be due to the exhaust O2 sensor. Full throttle runs revert to the pre set maps while cruising uses the O2 sensor to adjust the air/fuel ratio for best fuel economy. Can't think of any other way to test this.

 

[rizal_E34]

I opened up the ecu today.. but couldnt find anything interesting in the box, although it says i hv the right 1jz manual ECU. It says 1JZ-GT M/T and a lot of numbers here and there.

O2 sensor is a logical culprit. wd u know if we wd be running ori O2 sensor or 1jz sensor? where can i find this?

 

[seech]

I opened up the ecu today.. but couldnt find anything interesting in the box, although it says i hv the right 1jz manual ECU. It says 1JZ-GT M/T and a lot of numbers here and there.

O2 sensor is a logical culprit. wd u know if we wd be running ori O2 sensor or 1jz sensor? where can i find this?

For my faulty ECU you could see some burn marks on the circuit boards.

As for the O2 sensor, I'm not 100% certain but it should be on the downpipe after the turbo unless you have changed the downpipe. Logically I would assume that only the 1JZ O2 sensor can be used with the 1J.

 

[tkk]

happy with 1jz in E34... the car can really deliver the power as compare to previous M50 engine... fuel comp is about same...

for Rm100 - 380-420km PJ/KL driving
for Rm110 - 550-600km full highway to SG/PN driving 130-160kph

 

[rizal_E34]

happy with 1jz in E34... the car can really deliver the power as compare to previous M50 engine... fuel comp is about same...

for Rm100 - 380-420km PJ/KL driving
for Rm110 - 550-600km full highway to SG/PN driving 130-160kph

tkk, did u mod ur 1j or running standard?

seech/rtgp, I already found someone who wants to let go his ECU for an aftermarket unit. Im still uncomfortable since I cant find a reliable mechanic/wshop to diagnose my ECU/O2/1jz engine. Any recommendations, please?

 

[seech]

tkk, did u mod ur 1j or running standard?

seech/rtgp, I already found someone who wants to let go his ECU for an aftermarket unit. Im still uncomfortable since I cant find a reliable mechanic/wshop to diagnose my ECU/O2/1jz engine. Any recommendations, please?

Bro, dunno where you can go for 'proper' diagnosis. My mechanic has lots of experience with the 1JZ and has done many transplants but does not have diagnostic equipment so its more on experience and trial and error.

Maybe the other 1JZ kaki's can direct you to someone with proper diagnostic equipment.

 

[rizal_E34]

Bro, dunno where you can go for 'proper' diagnosis. My mechanic has lots of experience with the 1JZ and has done many transplants but does not have diagnostic equipment so its more on experience and trial and error.

Maybe the other 1JZ kaki's can direct you to someone with proper diagnostic equipment.

u wanna take me yamcha w ur mech?

well, i suppose all the 1jz taikos dont use IT to diagnose..i open up the diagnose socket and all is rusted

doesnt matter la.. just wanna get some feedback on the condition of my 1jz and wiring.

 

[seech]

u wanna take me yamcha w ur mech?

well, i suppose all the 1jz taikos dont use IT to diagnose..i open up the diagnose socket and all is rusted

doesnt matter la.. just wanna get some feedback on the condition of my 1jz and wiring.

Caaaaannnn..... he's located at the Jalan 223 area in PJ. When you want to go? His yumcha time is around 4:30pm. Today? or another day?

 

[rizal_E34]

cant do today, but tmrw i hv mtg at KL sentral ard 2pm. Then can run over to 223. PM me ur number?

 

[tkk]

tkk, did u mod ur 1j or running standard?

seech/rtgp, I already found someone who wants to let go his ECU for an aftermarket unit. Im still uncomfortable since I cant find a reliable mechanic/wshop to diagnose my ECU/O2/1jz engine. Any recommendations, please?

below are the specs for my car and minor upgrade so far
- running 0.6bar dyno over

 

[rizal_E34]

tkk, how do u vary turbo pressure from 0.6 to 1bar? at 1bar, i assume its torturing on the turbos? and FC?

wats FMIC? (duh!)

oh! u have AFC!!!! wat does it control actually? ECU?

 

[rizal_E34]

tkk,
im interested to run SAFC. whr do u tune urs?

 

[j-E34]

mine
RM100 city drive can go for 350-400km(not so jam traffic), 300km-350km(at least 3day approx 1-1hr30min stuck for jam in morning and afterworking hour )
RM100 hiway cruise at 100km/h-120km/h ----450km to 500km
RM100 hiway at 140km/h-200plus----300km-350km

beside ECU problem will coz makan minyak, turbine problem also.... when my turbine kong RM100 can go around 220km-250km at city drive