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Z

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Discussion Starter #1 (Edited)
I went to Dyno Spot Racing today to dyno and tune in my HKS AFR today. I am BPU with FMIC. running 50/50 mix of 91 and 100 Octan. for some reason I couldnt get pass 16psi on all my runs...guess there was boost leak. Plus, it was a humid rainnning day and the air fan they used was as big as the one I have at home... My results are 388WRHP and 392WRTQ...135,000miles on the engine.
The thing that concern me the most is my A/F ratio. I had EGt problems for a while now and have changed my fuel pump, fuel filter, and HKS fuel pressure regulator which didnt help me at all.
at my fist run my dyno # was 374WRHP with the car running 13.4:1 A/F ratio which is way too lean. we dialed in 15%more fuel with HKS AFR and picked up 10 RWHP and lowered my A/F ratio to 13:1...which is still too lean for comfort. However, when we dialed in 25% increase the result didnt vary much with 12.9:1, so the guy told me to back down to 15% so I wont overload the injectors.
I later discovered several loose vacuum hoses at FPR and on the intake manifold which I suspect is the reason why I'm 7psi short on fuel pressure at full boost. I am gonna do some testing this weekend and see how my EGT goes, if it still shoots up to 760C, I'm gonna take aprt my injectors and have a good look at my fuel lines.

Any thoughts on my A/F #? any suggestions or comments?

thanx

Jonas
 

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Loose as in the hoses were not connected??? If so your lucky you still have a motor. I've heard of people using that hose for a boost gauge line, and having it pop off under boost and bye bye engine...

No reason to suspect injectors or anything else until you get the FPR fixed...
 

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You're right, it sounds like your injectors need balancing and blueprinting(cleaned) Checking your lines is a good idea too...

Great looking car! :D
 

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Take grant's advice first, but clean fuel isn't a bad idea...
 
Z

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Discussion Starter #5 (Edited)
GRant,
loose vacuum hose meaning when I pulled on it, it comes off without too much resistance. thats why I think my fuel pressure at idle and 0 Psi is good, and when it goes full boost by which the fuel pressure supposed to raise to 4.5 bar, the hose starts to leak and I only get about 4 bar. now that I have rechecked all my vacuum hoses and replaced lose ones (especially the one at stock FPR), I 'm gonna do couple of runs and see how the car reacts.
is 13:1 A/F ratio at dangerous level? I was told that its a bit high, but not bad enought to blow my motor, just dont run 18psi with 91 octan anymore. My A/F curve declines quite evenly so thats good I was told. but I'm trying to figure out why my A/F ratio is so high...could low Fuel pressure be the cause?

Suprat, thanx for the comment, yeh Grant has been helping me with my A/F issue for a while now and I take his comments very seriously.

Jonas
 
Z

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Discussion Starter #7
DSR is very professional at what they do. the shop is clean and they guys know what they're doing. thats they only place I'be going to have my car dyno tuned for sure....but not a place I would wanna go just for baseline pull cuz they charge $185/hr
 
J

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Discussion Starter #8
Have you changed your fuel filter lately?

Jason.
 
Z

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Discussion Starter #9
yup, changed it 3 weeks ago when I changed my fuel pump amd fuel pressure regulator all together.
 
J

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Discussion Starter #10
Well, I guess you are pretty much down to Fuel pressure regulator (like the hose issue mentioned) or clogged injectors. What do the plugs look like? Do they all look the same? Do they look lean (white)?

Jason.
 
Z

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Discussion Starter #11
they are white...i know I was running lean for a while now. I was using NGK6097 plugs. now I have changed to Denso Iradium degree#7. I havnt tested my car since the 12V fuel pump mode and dail my BCC in the right voltage, will do that tonght.
 
J

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Discussion Starter #12
Did all 6 plugs look like they were equal in color, none lighter or darker than the rest?

Jason.
 
J

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Discussion Starter #14
Well, you can most rule out injector problems. I would lean towards the pressure regulator at this point.

Jason.
 
Z

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Discussion Starter #15
I tested the car last night...EGT still shoots up to 750C at the end of 4th gear pull.:mad:

I did the 12V mode and had the BCC tunned in, no help. I dialed in more fuel but only to find my car jerking under hard sudden acceleration (maybe too much fuel?)
met another supra member from SJ, Richi, and he told me to have my ECU code read and check my stock MAF sensor for false signals. DO I need to go the dealer to read codes?

thanx guys...

Jonas
 
Z

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Discussion Starter #17
Andi,
I checked my code and 35 came up....turbo pressure sensor?
any idea what it could be? I have disconnect all electronics and have put my car back to stock. gonna try to anylize the problem step by step...

thanx

Jonas
 

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Zerosoul said:
Andi,
I checked my code and 35 came up....turbo pressure sensor?
any idea what it could be? I have disconnect all electronics and have put my car back to stock. gonna try to anylize the problem step by step...

thanx

Jonas
That means you fucked up the BCC install and deinstall and is the reason why you're going lean.

Andi
 
Z

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Discussion Starter #19
but I have no check engine light poping up...plus, when I hook back the BCC last night, no codes came up afterwards.
 
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Discussion Starter #20
Hey Zerosoul...those EGTs don't sound right. Once you get it dialed on the wide lambda and u know everything is working well, u can use your EGT as reference, but in your case I don't know because those temps are definitely off. Especially if you're going wide open throttle doing dyno runs.

I'd check the EGT probe, connections, guage, to make sure everything is working right. Although the EGT in and of itself is not an absolute tuning device, when you use it together with the wide lambda, an EGT is the best guage you can have in your car to tell u what;s going on.

What was your dyno readings by the way? What did you pull?
 
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