MalibuJack

iTrader: (5)

Actually fuel starvation in the fuel rail is actually a REALLY good point.. since if there's fuel starvation, the furthest from the inlet will probably be the one that runs lean.. and since 3 of the 4 cylinders would be rich or normal, EGT's and AFR's would probably read fairly normal.. I never even considered that.. Are you running the stock fuel rail?

projekzero

i would never tune with an egt gauge alone. as would anybody. having it downstream will cause it to read lower, however it will still show changes in temp. i would always tune it to run ans cold as possible nomatter where it was located, but i always try to first tune my a/f with a wideband. just cause the instructions say it should be mounted 2-3 inches from the port doesnt mean anything i doubt it takes into account weather you have something inline plumbed in (such as a turbo). once my vehicle is tuned i know what my normal egt's are and i always change adjustments to keep it in that range. i more or less use the egt as a means of fine tuning and a warning indicator. yes a/f gauge lets you know how much fuel you need to add or subtract, but the egt realy lets you see the combustion effiecncy, also changes in timing will be visible. like i said fine tuning.

its not gonna cause the motor to get fuc*ed up at all. only the idiot tuning it would cause that.

dont give something an oportunity to mess up, nothing will mess up. i'll plumb it downstream.

Predator67

Ya i am running a stock fuel rail as under group N specs I cant change it. But then again, all the other cars are also running on stock fuel rail.

patsevo8

did you have enough fuel flow

Predator67

By way means do i check that. fuel pressure was stable though.

timzcat

iTrader: (10)

How many miles are on the car?
Fuel Filter would definitely cause starvation, especially under heavy load.
Also, since it is #4 and that is FPR outlet on the rail the FPR could be stuck open. This would be more prevalent the further from the inlet on the rail due to pressure drop across the rail.

From the pics, the #4 cylinder combustion camber is too clean which means it was too lean and it was probably runing like that for a short while to get that clean in the cumbustion camber.

Now for my comment that will get lots of arguement.
When a cylinder is lean, contains too much air and not enough fuel it will recruit a fuel source which ends up being aluminum like the piston. This is very common on NOS injection because the pure 02 is so prevalent in the cylinder. This is why high silicon content in aluminum pistons is a better piston. It is more resistant to conversion to a fuel source. I know a majority of people want to argue this with me but you can PM me and not OT this thread.

timzcat

iTrader: (10)

What was t he fuel pressure at 6500 RPM when the warning went off?
Assuming your base setting is 3 bar roughly 45 psi and you are pushing a steady 24psi of boost then on a 1:1 rising rate FPR you shoud have had upwards of 70 psi under full boost. Do you agree with me?

Predator67

Fuel pressure was ok. About 3.0 bar at vacuum off and about 4.6 bar at 1.65 bar boost. Explored that area earlier.

gunzo

iTrader: (2)

MalibuJack, his stock fuel rail is bigger than yours !! (so to speak!!)

Find a JDM VII picture, and you'll see that VII fuel rail is the size of an aftermarket fuel rail !

erioshi

Where are you grabbing the fuel pressure reading from? I'm just currious.

MalibuJack

iTrader: (5)

LOL That never occurred to me.. Timzcat's point about a clogged fuel filter or stuck FPR is a good one too.. (FWIW I should have known that.. I've been researching upgrading my fuel system recently a bit more extensively than just a pump and injectors)

gunzo

iTrader: (2)

Hey .. if the price is right .. the stock VII rails is the same size as a HKS unit .. why not go for that for the stealth look ??

MalibuJack

iTrader: (5)

I don't think the GT35r turbo would pass off very stealth.. I'm wondering how many of the really quick cars are still running stock fuel rails?

93h22cvc

any nos used?