Outer Limits 4x4 Board

took my brothers prado for a drive yesterday (stock 3rz)to see weather it lacks power and its the same as my hilux.

Ha, just noticed something even weirder with mine tonight on the way home. Mine seems to "hit the wall" at 4000rpm, but clears up at around 4700rpm to rev smoothly to the rev limiter... Mine has done this since the conversion, but keeping in mind that mine isn't a stock intake, and the MAF is placed only about 6inches from the throttle body, so that could too be a problem. This will be fixed soon, but hey, I can't do everything at once can I Too many things to fix on the 4by first!

smaddock wrote:Ha, just noticed something even weirder with mine tonight on the way home. Mine seems to "hit the wall" at 4000rpm, but clears up at around 4700rpm to rev smoothly to the rev limiter... Mine has done this since the conversion, but keeping in mind that mine isn't a stock intake, and the MAF is placed only about 6inches from the throttle body, so that could too be a problem. This will be fixed soon, but hey, I can't do everything at once can I Too many things to fix on the 4by first!

I have some weird stuff going on here too, tonight on my way home it had regained all lost power and pulled hard to just before the limiter but still wouldn't hit the limiter except in first. Be f*ked if i know.

I had a mate driving behind me today, he said as the car backfires before it hits the limiter it throws a flame out the exhaust, this was during the day and he said the flame was about 300mm long. Im guesing its running rich? What could cause this? Im running standard computer and the same intake as yamaha__308.

BTW all the power seems to have returned and the flat spot has dissapeared.

Good to hear you got some of it sorted mate. Some good info here.

What's your fuel pressure at now with the backfire? Timing spot on? And plug leads ok?

yeah there is some very helpful info in this thread. Fuel pressure is at 38psi, leads and plugs are about 11months old. Not sure about timing as i haven't touched it since Ive had the motor, doubt it would be timing related as it didn't do it before the intake was done.

it seems to me like its not getting enough fuel or air. intake sounds like its sorted now so id be looking at fuel next as it should hit limiter easily in 2nd and even 3rd, can u run me through your fuel setup again from the tank to return, what have you got and where?

stock tank, lift pump, surge tank, msd high pressure pump, malpassi fuel reg set at 38psi. injectors have been cleaned and checked. Its not running lean, it uses a fair amount of fuel and throws flames out the exhaust just before the limiter. Not sure if you've read the last few posts but im having no issue hitting the limiter and all the power has returned, only issue i have now is it gives a small backfire just before the limiter but only under load and when it does it throws a flame, even during the day its visible.

FLAMES are cool deal with it

rito i was going off 3rd post down on this page. mine throws flames aswell just before limiter probally because i dont have a cat converter i would of thought, are you running one? no idea if thier the same but in my mates commy the cat collapsed so he ripped the guts out of it and the fuel consumption went through the roof. dont know why? any one else heard of anything like this?

AFAIK, 3RZ's didn't come with cat converters.

Now I wanna go see if mine throws flames...

Im not really worried about the flame, i just thought the flame is caused by unburnt fuel? This is fuel i could be saving. Also i dont like the backfire it gives before the limiter. I can live with the fuel usage and the flame but id like to loose the backfire.

i had to get cat for blueplate and exaust shop wouldnt do the exaust without putting one in. mines a 2002 out of rzn, no egr but need cat. i dont know if mines backfiring just before limiter, by the time that its at that revs its so loud you cant even hear yourself think. its not noticable thou

are you guys using 4wd or 2wd ecu's
i have a simular problem with a 01 on duel fuel goes good on lpg but on pet
has flat spot between 2500 and 3500 then clears and revs right out
have replaced air cleaner,fuel filter,plugs,leads,cleaned air flow,adjusted trim pot on inner gard
went for a drive with my 02 meter and the engine is running lean
i think i will put in an adjust able presure reg and see how that goes.
i asked a mate who works on 4wds and he seid to keep an eye on tapet adustment but have not yet done mine.
i have one 2wd at work and it goes heaps better then mine and it alwas has a load in it and has more kms.

gavlux wrote:are you guys using 4wd or 2wd ecu's
i have a simular problem with a 01 on duel fuel goes good on lpg but on pet
has flat spot between 2500 and 3500 then clears and revs right out
have replaced air cleaner,fuel filter,plugs,leads,cleaned air flow,adjusted trim pot on inner gard
went for a drive with my 02 meter and the engine is running lean
i think i will put in an adjust able presure reg and see how that goes.
i asked a mate who works on 4wds and he seid to keep an eye on tapet adustment but have not yet done mine.
i have one 2wd at work and it goes heaps better then mine and it alwas has a load in it and has more kms.

I had a 4wd ecu and drowned it, swapped it with a 2wd ecu and there was no difference in power or power delivery

Interesting... I am using a 4WD ECU, intake as above and a stock fuel regulator. I am also finding a flat spot around a similar rev range, hard to tell without a tacho. The flat spot is not noticeable, until you rev past it and the power hits.

Anyone having similar problems with a stock 3RZ or is this just a conversion issue?

my stock fuel reg was fubar when i got the motor, it ran fine but had no more power than the 22r. Try clamping off the fuel return and see if the flat spot goes away.

im using 2wd computer and stock reg. aqs yamaha308 said its hard to notice the flat spot without a taco

it would be worth trying what i said, faulty fuel regs are common on this motor

dillza_69 wrote:it would be worth trying what i said, faulty fuel regs are common on this motor

Will do mate, cheers.

hi guys

i have a similiar flat spot with my 3rz and would like to check the fuel pressure. where are you guys connecting the pressure guage. after the fuel filter and before the injector rail ?

cheers
andrew

anywhere before the fuel rail but after the pump, the closer to the fuel rail the better

i never had those problems with mine, it had good power right the way threw, altho there is a definate rev range on all 3rzed cars iv driven were they seem to pick up a little extra go, altho alot of it seems to be intake noise lol.
Out of interest, are any of u guys running the "boost box" aka intake expansion chamber thats surposed to keep the intake noise down?
Just a thought but thats were the line for the fuel reg runs too, and with that line straight into the intake tube may not create enough pressure or too much or something?

Mine now has a def flatspot tho, and a def large hit of power after ahahaha

No intake resonator on mine. Can't tell much intake noise, between the gearbox whine, wind and exhaust..

I would say it feels like more of a power spot, than a flat spot. Car goes great guns though. Will check the fuel reg though.

every thing on mine is stock. from air box to throttle body and fuel pump to to rail and charcol canister.

Mine's doesn't have the expansion chamber, and fuel reg line is run to manifold vacuum, BUT I have a Haltech Interceptor piggyback ecu, and is remapped, so it shouldn't matter what the fuel reg is doing, my fuel maps are adjusted to suit. I guess the problem is if the fuel reg is stuffed, that could explain why, say 90% of the time the flat spot exists, but every now and again it just revs right thru the flat spot area with heaps more power... ahhhh bloody 4wd's!!!

yamaha__308 wrote:I
Anyone having similar problems with a stock 3RZ

yes.. since the day I bought it which was 4 yrs ago with 95K on the clock..

have tried filters, plugs, leads, tappets and all with no change..

I have resided myself to the fact that it's just the way they run... but it's starting to shit me again so I may cough up the $$ and take it to Toyota and get them to see if they can work it out ????

Mines got a miss sorta deal at idle, nothing drastic.. Nothing under load though. Has ran perfectlly for the years ive had mine in my 106r. Had a slight fart around 3500 but this was fixed by cleanin the afm n cleaning the idle control valve under the throttle body. And getting rid of the diesel algea outa my tank from the 2.8. That was my main hassle, it fukd my injectors too.. I pulled em out the other day n theres shit all over em.. So in go the 550's now

yamaha__308 wrote:Anyone having similar problems with a stock 3RZ or is this just a conversion issue?

Sort of, kinda... Engine wise, mines a stock as a rock 99' model with only an Exhaust system added, no extractors, just the back half... Not really identical to problems you guys are having but has just lately really been a struggle to keep running at idle, used to idle around 800 to 1000rpm - ish smooth as silk... but now struggles real bad and continually drops down to 400 - 500rpm and coughing and spluttering as soon as over 1200rpm again it comes good...

I do however have a little bit of flatish spot about 3500 to 4200, starts off quite revvy, builds quick, hits 3500 ish and doesnt die, but just stops climbing as easily but then hits 4200 - 4300 and bloody BOOOMMMMM its like a powerband and off she goes... Dunno why though just always done it

But yeah thats all stock, no conversion