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Discussion Starter #1
A little back story. I bought an already swapped 1jz car. Already had proefi128, driftmotion 6465 turbo kit, id1300's, walboro 450 fuel pump and a few other bits and pieces. It was tuned by a very reputable tuner out of Florida. I bought the car out of Phoenix. It's actually a white sc300.

My issue, on my first iboost setting (wastegate 10psi) it drives great and pulls great. On any other iboost setting it will cut out every now and then and I've noticed my afr's hit 30 when this happens. Yes, I said 30. This happens on 93 or e85.

I'm stumped.
 

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It's a tuning issue, which unfortunately no one will be able to diagnose over the forums without you posting quite a bit of screenshots. I wouldn't be surprised if there was a failsafe that was going off.

Actually, does it have ONE walbro 450 or more than one? If just one, that's your problem, anything above roughly 10 psi on your setup and fuel pressure is dropping because the pump can't flow enough for the airflow.
 

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Ah, well then I'm positive you're running low on fuel. If you're familiar with how to take and save a log using the ProEFI software, save a log of you going WOT in iboost setting 2-5 (as long as the log has fuel pressure, boost, rpm etc) and you'll see fuel pressure drop like a rock after 10 or 15 psi.

You can always install a second fuel pump and have the ProEFI stage it on when you get to positive boost, then turn it off when not in boost (so as to not heat up the fuel in the tank by running both all the time).

Your 6265 is rated for almost 700 hp at full kill, a single walbro 450 can't flow enough to support that. Low boost you'll be fine.
 

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Discussion Starter #5
I'll go log it and see what fuel pressure is doing. It's doing it at 15psi. From the dyno sheets I got from the previous owner I wouldn't think I would be maxing that pump out. Who knows, I'll go log it.
 

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You must of bought Corell's old SC300. You got a great deal, Just add one more pump and some larger fuel lines and your in business.
 

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Im doubting its the fuel pump. Unless his other boost setting is like 25+psi on e85. I made the numbers and times on a single walbro 255. I've swapped to a 450 so i can up the boost a little to run some 10's this year. That pump on race gas can support high 600's.
 

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Discussion Starter #9 (Edited)
Normal run not messing up. Sometimes I get lucky. This was the first run. 3rd and 4th gear.


Right before it hit 30AFR. 3rd and 4th gear


This is hitting 30AFR


It does do it in all gears. Sometimes as soon as I hit it and some times itll let me go through a full gear then cut out in the next gear.

This car is still somewhat new to me. I turned It down to my iboost 1 setting (10psi) and at the top of 4th it DID do this same thing.
 

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It looks like fuel pressure isn't dropping, so it has to be another failsafe or cut that's set up.

Correct about the 450 running big numbers on pump gas, I'm not sure why I assumed it was e85 haha.
 

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Im not sure what the cars power lvl is.

Cant read the blue curve either what is that?

Maybe stock fuel lines? and they cant handled the required fuel and is surging for more fuel
 

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Discussion Starter #16
At 15psi it's making less then 500. Found out the fuel pump is a 485 not a 450. With id1300's and stock lines I wouldn't think it should be running out of fuel.

The blue curve is the afr. Everything is good then all of a sudden it spikes to 30afr. It's very random on when it does it.
 

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I should think the fuel lines should be ok still,
Up to 500-550 whp: Stock Fuel Lines
Up to 800 whp: -8 AN supply Line; -6 AN return Line

there are like Three names for the E85 450 pump.. I use the number Walbro F90000267.
Pump sounds like it should be good to.. Id say its a computer tuning issue. If you aren't capable and or dont have one already id get a reputable tuner as local as possible to look at it.

I thought most Failsafes would cut ignition.. so It shouldn't Be able to lean out like that? Im not experienced enough but that is just my thought.
 

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Discussion Starter #18
That's another issue I'm running into. I'm in Arkansas and no one around here knows proefi well enough to know what to look for.

Any suggestions on good tuners close to Arkansas or that will travel?
 

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There are plenty of Remote guys if you have a labtop and solid internet connection that would be willing to help. As for anyone near Arkansas I'm not sure...Maybe someone else will chime in with some good possibilities aswell As for my input dont drive in top rpms where the AFR were spiking until an issue is found/resovled to prevent possible damages
 

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That's another issue I'm running into. I'm in Arkansas and no one around here knows proefi well enough to know what to look for.

Any suggestions on good tuners close to Arkansas or that will travel?
Where are you in Arkansas out of curiosity? I don't know of any tuners, I plan on going to memphis area to tune my JZFC when it starts making real power. I have a few people in mind but I'm going to be very careful about who I talk to.

I live in Jonesboro which is full of camry's with ebay trunk spoilers, trucks with the exhaust cut off that think they're the next best thing, and a few decently modded cars, but I would definitely be interested in talking JZs if you're near.
 
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