1jz boost leak

[91 mK3]

i have just done a 1jz swap into my mk3 and i cant even enjoy it because i have a boost leak somewhere (or atleast i think i do). I have a stock fmic with 2.5" aluminum piping with brand new not cheapo silicone couplers. i am at stock boost and the only mods that i think would have any affect on it would prob. be the 550 injectors with stock twins. I have also got a cap and put a valve stem and have put it on my piping to stimulate a turbo while blocking off the other side. i tried to listen for the leak but didnt hear anything so i took it off, took it for a drive and it felt horrible. It felt like having a 7m w/ a code 21 where it would hesitate around 2500-3500rpm and then just go. any ideas on some test or do i just need to get tuned?

[JASONA70]

i had someone rev the engine a little while i checked around for a large masses of air, which you will feel when someone revs the engine.

[The Reaper]

you running 550's with no fuel controller? SAFC, EMANAGE, AEM???

if so then thats prolly your problem. the 1JZ runs pig F'in rich stock

[91 mK3]

i already have the safc 2 installed in my car. this 1jz actually came out of another supra. it was tuned for 14psi of boost. so what a good friend of mine told me was that every supra is different and its not going to run the same way or even better until i get tuned.

[91 mK3]

hopefully that is the situation. any other ideas for boost leak detection?

[Burntz]

yea u really need to tune it correctly. for boost leak um.. have a friend rev it while u stand thier, and if theirs a leak, at a certain rpm you should hear the pressure escape somewhere.

or thiers a method where you hook an air compressor up to something yada yada and it does the same thing. iv never done one lol

But with experience from friends cars, if you have a leak, you hear it.

[suprastanger507mgte]

Actually, they do.

14psi on stock fuel is perfectly fine. You'll blow the turbo's before the stock injectors run out of fuel.

Set your SAFC2 to -33% across the board and enjoy a good running car again. Better yet, just borrow someone's wideband, you can probably go leaner.

How can you determine he needs exactly 33% less fuel exactly>>>????

[Burntz]

Owned. Lol.


Crazy what a little bit of math does :P

[suprastanger507mgte]

Because 550's are exactly 33% bigger then stock.

And that is the only factor you take into consideration ?

[91 mK3]

so subtract 33% equals stock fuel which would equal no hesitation? what you think moe? lol

[suprastanger507mgte]

so subtract 33% equals stock fuel which would equal no hesitation? what you think moe? lol

Its your car...you can listen to anyone you want, or you can take it to a qualified tuner with the right knowledge and tools to get it right. If it was as simple as that, I would have done that myself and let you boost your heart out...till you blow up the engine or melt a piston...

[Van Diesel]

Its your car...you can listen to anyone you want, or you can take it to a qualified tuner with the right knowledge and tools to get it right. If it was as simple as that, I would have done that myself and let you boost your heart out...till you blow up the engine or melt a piston...


I have verified this with a wideband. Seriously. 33%. Honestly, I did it twice. Once with 440cc and once with USDM 550cc.

[91 mK3]

Its your car...you can listen to anyone you want, or you can take it to a qualified tuner with the right knowledge and tools to get it right. If it was as simple as that, I would have done that myself and let you boost your heart out...till you blow up the engine or melt a piston...


all imma say is that you need to hurry up man. lol. lets go our cars tuned. even better, lets organize a meet so whoever is not tuned can get tuned. maybe the guy will lower the price.

[suprastanger507mgte]

I have verified this with a wideband. Seriously. 33%. Honestly, I did it twice. Once with 440cc and once with USDM 550cc.
How can 440 cc injectors be the same as 550cc?

[Van Diesel]

they aren't. But when using 440cc injectors and you remove 16% fuel top end it tells me that the formula works.

When I went to 550cc and removed 33% with my SAFC and at WOT it put the A/F ratio almost exactly the same as the stock 370cc. IIRC it was actually sightly richer. I don't have 550cc's anymore though, and have since gone with the stinger4.

[The Reaper]

Ric is actually correct on this.....did i just say that? hahahaha

around 33% taken out it puts it damn close to stock. as long as your wiring is good it will be fine....but you'd be better off getting an AFPR. lower fuel pressure then minus out only 15-20%.

cause on piggy backs, you can only take out so much fuel before you start messing with timing too much....THEN you melt pistons

[The Reaper]

haahahah yea

my friend did this on his 1J and did a long highway pull and melted his piston in like 10 seconds...LOL not cool

[The Reaper]

Chino??? no Aaron...he isn't on this board.

he dyno'd 308whp and 313trq on 18 psi and i told him it was detonating and he didn't listen. he went out clubbing later that night and decided to do a highway pull to see if cutting the speed wire disabled speed cut and it started hesitating at 120mph and from then on it idled like a WRX.

we haven't torn it apart or did a comp. test but its definitely down a cylinder. cracked or melted piston im sure

[The Reaper]

same with him

AF was in the low to mid 11's and he had slight detonation and pop there went the 1jz

[The Reaper]

nah he didn't have an FCD....just SAFC2 AVCR 550's and walbro

AEM WB UEGO

tuned to 11-11.5 AFs

and POP

[The Reaper]

very true

[Van Diesel]

Weird, but then again these are junkyard motors from japan, anything is possible.

Well junkyard in the sense that the Japanese government sucks. For instance, for you to own a car, you must have a license. If you want to buy ANOTHER car, you must SELL/JUNK your first car BEFORE you can purchase the second. There is no such thing as "TRADE-IN" to the dealership. If you can't sell your car...you're better off junking it so you can get the car you want. Sucks but true. I lived in Japan for almost 7 years. I got fucked many times buying/selling cars.:icon_evil

[The Reaper]

^^^ holy crap that is officially the GAYEST thing i have ever heard.

nm i dont want to live there anymore

[Van Diesel]

well. I bought my JZA70 for $2000 USD. Then got Recaro seats + rails for $200, Blitz K26 kit/JIC suspension/Kaaz diff/cusco front & rear STB/ARC IC for $1000. Tack on my HKS cams and gears/fuel pump/OS twin plate clutch/sard 800cc injectors/stinger4 and I've spent less than $4500 on my car...including the price of the car.

Sucks to buy/sell cars. But as a car enthusiast who wants to save a little cash...Japan is where it's at.

Plus I'm mad JDM tyte yo.

[The Reaper]

hahaha true

i'd love to visit japan but im afraid i will want to stay haha

[Van Diesel]

haha. that's what happened to me. I visited and stayed.

[The Reaper]

yea thats why my wife wont let me go LOLOLOL cause she doesn't wanna live there :)

[Van Diesel]

I got a set of Nissan GTR 17" X 9 rims in pristine condition for $600 at upgarage. Sold them for twice that.

I have 4 sets of rims. I paid less than $2000 for ALL 4 sets with 2 sets having almost new tires. Damn I miss Japan sometimes.

[The Reaper]

where can you get bride seats for 200 LOL

[suprastanger507mgte]

wtf : My friend started this thread about boost leaks....how did it end up being a discussion on what you can get from Japan?>>>

[The Reaper]

well did you figure out his problem???

if you think its a boost leak do a leak test....

[91 mK3]

the only conclusion we have is that its running rich. i couldnt find a boost leak anywhere.

[The Reaper]

you running 550's with no fuel controller? SAFC, EMANAGE, AEM???

if so then thats prolly your problem. the 1JZ runs pig F'in rich stock

and i answered your problem in the very beginning

[suprastanger507mgte]

and i answered your problem in the very beginning

Not really. He has a fuel controller for the 550's and It was tuned a bit on the richer side on a dyno while this engine was in my car. since we put it his car - and nothing on the safc has changed settings or wiring wise we were wondering what could be causing the hesitation.
Boost leak was tested for, and nothing was found leaking.
I think the driving style and lack of time with this engine may be contributing to more questions for the owner :)

It does hesitate when stomped on , or boosting ( floored from the start)
Hesitates on the top end as well. We will put it on the dyno again to make sure the tuning is fine. Maybe his fuel pump/pressure is weaker?I don't know....we will figure it out though...

[The Reaper]

interesting

hesitation could also be something with a clogged fuel filter timing is probably being pulled?

[sc250tt]

interesting

hesitation could also be something with a clogged fuel filter timing is probably being pulled?

yup my 1j first 1j sc had the same problem and it turned out to be the fuel filter , too bad i found out too late and my engine started knocking on startup :nono:

[suprastanger507mgte]

interesting

hesitation could also be something with a clogged fuel filter timing is probably being pulled?

YEah could be. I was leaning more towards the stock MKIII pump.