3rz-fe.....40 ltrs per 100ks

[alper5005]

Mine had the same problem. However had a very serious valve issue. If it gets harder to start on mornings I can say have your valves readjusted first. Sticky valves or misalignment can cause that but then you would notice a dropdown in power. Or else it could be an ECU problem.

[dillza_69]

Onto something more helpful...

The occasional 3rz burns a valve for a few reasons, which would result in bad fuel economy, but would also result in a rough running motor...

If all else fails, compression test it.

Have you wired in the cold start sensor assy?, if not it shall punch in massive amounts of fuel
Is your original intake the same diameter as the 3rz intake, if it is not it could be running to lean or way to rich.

If you've done a engine conversion it should be pre wired with the ecu in the loom.

Are all the cold start hoses connected to where they should be for eg, pre throttle body , post throttle etc.

What is this and where is it located?

[jimmy087]

jst caught up on this thread some good ideas i not long finished a 3rz conversion before tuff truck and had a wow of a time getting it to run properly and in the end it was because i was too lazy to follow a wire back to the ecu for the correct pin location on a power wire so double check that wire locations are right and not particually the wire colour after that i would be leaning heavilly towards the temp sender, check the plug condition and wire security within the connector as it is very vulenrable at the back of the head it may have been bumped in the process, if u have a manual great if u dnt get one cause they are really handy as it gives you the proceedure to check airflow meter power and earths and even resistance through the hot wire. should have 5 volts there and at the throttle posistion sensor. i also think there is a resistance check on the temp sender in the manual i have, if any of these values are out slighty then it can have a big effect on economy. i dnt recall you saying the fuel pressure was correct cause the standard regs are renowed for throwing in the towl unexpectedly aparently. mine has a malpassi reg and is set to 40 psi which i here from DGR dave is ideal and think that is very close to standard pressure anyway. but really unlikely would be the cause as even if it was high i dnt think it would use that much fuel in normal driving circumstance sort of sounds like a combination of problems which can offten be the case as i deal with complex canbus systems every day of the week and nothing is impossible. Another thing i jst remembered do you have that little plastic box with two bolt holes in it, sort of looks like you could adjst it. it is on the same strand of harness as the airflow meter as this was missing from my harness and had to chase the wreakers to get it off the inner guard of the car as they had jst unplugged it, im pretty sure it measures air temp and or atmospheric pressure, not sure what the result would be if it wasnt there but worth looking at. i like what berad said about playing with it urself you learn heaps about engine functions and when something does go wrong in the scrub you have that knowledge to get you going again. good luck

cheers jimmy team ohdeere 2010

[dillza_69]

Another thing i jst remembered do you have that little plastic box with two bolt holes in it, sort of looks like you could adjst it. it is on the same strand of harness as the airflow meter as this was missing from my harness and had to chase the wreakers to get it off the inner guard of the car as they had jst unplugged it, im pretty sure it measures air temp and or atmospheric pressure.
cheers jimmy team ohdeere 2010

I spoke to toyota about that and it turns out its and idle mixture screw, A Special service tool is required to adjust it.

What manual do you have and where did you get it from?

Mine runs perfectly except for a slight missfire at around 2000rpm but i need 50psi of fuel pressure otherwise it starts to idle rough and looses power. I have had the injectors cleaned and tested and they were fine.

Im getting 200-250km around town on a 40lt tank. Seems a bit heavy to me

[virtha21]

i get around 500kms out of 60lts with 33inch tyres

[jimmy087]

dillza u must have an after market fuel reg and guage too i take it? if i was u i would screw it back to 40 and find the real reason for it running rough more like a faulty idle air control valve or try cleaning your airflow meter with some contact cleaner as if the fillment inside gets dirty the air passing the wire can no longer be metered accurately and in reality there is more air going in than it measures causing a lean out and a surging maybe felt if severe enough. if indeed it is a missfire at 2000 rpm and not surging how long since it had a spark plug change as thats what it sounds like. my manual is a haynes but i recomend trying to find a gregories or something better. try one thing at a time that way at least you know what it was when its gone.



cheers jimmy team ohdeere 2010

[dillza_69]

dillza u must have an after market fuel reg and guage too i take it? if i was u i would screw it back to 40 and find the real reason for it running rough more like a faulty idle air control valve or try cleaning your airflow meter with some contact cleaner as if the fillment inside gets dirty the air passing the wire can no longer be metered accurately and in reality there is more air going in than it measures causing a lean out and a surging maybe felt if severe enough. if indeed it is a missfire at 2000 rpm and not surging how long since it had a spark plug change as thats what it sounds like. my manual is a haynes but i recomend trying to find a gregories or something better. try one thing at a time that way at least you know what it was when its gone.
cheers jimmy team ohdeere 2010

Yeah mate got an aftermarket reg and gauge. All well and good to wind it back to 40psi and then fault find but i need the car for work every day.

I have cleaned the AFM wich made no difference. I have changed plugs and leads which nade no difference. I have been looking for an IAC valve as i suspect that is the problem but i cant seem to find one second hand and a new one from toyota is just a stupid amount of $$. Running 50psi is not ideal but after speaking to the guy that did my injectors he rekons 50psi isnt going to hurt them if anything it will run a bit rich.