R33 Gts-t Running Lean! Help! >>> Fixed!

[Mr_GaZZa]

Hi Guys,

since i've had a rebuild... from the previous engine running lean i decided to get it checked cause,

it seemed to randomly play up, like hesitate to pickup when on boost when its been driven for a bit!

at the time i had a stock BOV.

The engine contains,

Forged Pistons/Rings/Pins

New shells/seals ect

Bores slightly honed

Polished / Flowed Head

Spitfire Coilpacks

HKS POD

FMIC

On the dyno/s I am getting readings of 12-13PSI boost…

recently added

040 pump

front pipe

new fuel filter

i went to Hyperdrive to get a dynostic, on what could be my problem causing it too run weird… anyways on the dyno I got a AFR reading of 15.## ish " the AFR went in a small down and U shaped and headed up the chart till 5,000RPM.

The guys there said its more then likely the fuel pump, so a few days later Kenzi fitted me a new fuel pump " a Bosch 040 I was told.." I drove her out and she seemed to gone fine… few days later was back into going good … until getting 2/5 hot or 30mins-1hour of driving 'mixed, accelerating and cruising'.

and between that time I put a copy SSQ BOV on between that time, and held boost better... still had the problem but!!

And yeah, this Sunday I went along to the SAU dyno day, where my ran lean, it started @ 14is AFR droped to 11.## and U shaped and started to go up to 13:## ish AFR and start to slowly wavey down the chart… but they only went from 2500-3### RPM….

Every said get a new fuel pump, but I did… and I've replaced the fuel filter and just done the o2 sensor, which didn’t really help me in any way!! Even put a new front dump on… looking at turbo blades made me 'very white' so its differently lean!! And my sparkies are semi white / grey...

QUESTION !!! Is it true that my fuel pump needs a consistant 12v Earth? Cause its only wired to the factory wiring, and the guy who fitted tells me the rep said he provided a replacement 040 pump.. Coz changed names =S

I am so confused hey… I aint got much left to change... turbo, ecu , CAS, AFM and fuel regulator are pretty much only real things stockish not changed or serviced..!!

if anyone could help, please do!!!

Thanks

GaZ

Edited February 29, 2008 by Mr_GaZZa

[paulr33]

get a real ecu and tune it

[joeyjoejoejuniorshabadoo]

you bothered to do all this:

Forged Pistons/Rings/Pins

New shells/seals ect

Bores slightly honed

Polished / Flowed Head

on an untuned stock ecu?

[Guilt-Toy]

have you cleaned your AFM ? do you have a POD or stock air box?

[TTT]

have you replaced the fuel filter?

perhaps with the extra fuel required for boost, it doesn't let enough through.

[Mr_GaZZa]

Hey,

yeah "GTST", i have replaced the fuel filter about 30,000km ago, but yeah i put a new one in not long ago today... maybe its that?!

and "Guilt-Toy" i havent ever cleaned the prongs/metal things inside the AFM... was told to do it... considering i never done it since i had the car properly!!

since when can this make iyour car run lean?? and yeah Guilt... i got a OLD HKS superflower POD =/ in process of replacing!

anyone else got ideas?

Thanks

Edited February 28, 2008 by Mr_GaZZa

[Guilt-Toy]

AHHHHH

Im going through the same thing with my mates car....

Take the POD off and get a air box and also clean your AFM. there is a big chance it will richen it up.

Try it. you must try a standard air box.

let me know how it goes. do you have a air fuel ratio meter to test it ?

where are you located? i had the same prob with my mates r33, we took the pod off (hks mushroom style) put the air box back in and it works a treat now.

try it. if yours does the same thing then thats weird.... we need to find a fix for this.

can u try a standard air box for me ? and clean the AFM ? clean it with contact cleaner and i have used brake cleaner before as well.

[Kaido_RR]

get a real ecu and tune it

how will that solve is problem?

the stock ecu is made to go into rich mode, when the boost is increased, so something else is not working correctly. changing the ecu is just a quick bandage and doesn't really solve the real problem

Mr_GaZZa, get hyperdrive to put a pressure gauge on your fuel pump and it will tell you weather it is that or not

Edited February 28, 2008 by [Michael]

[Mr_GaZZa]

Hey every1,

they did my car today.... it was running like 1 BAR of boost!! ROFL

but yeah i still reach 12.5 AFR to about 4000RPM, then drops down to low 11's

probably the way i got my fuel pump wired, but i am going to get it 12v grounded to make it 11 AFR throughout the RPM

wasnt hhappy on the 221 RWHP it made =/ on 13PSI

[paulr33]

get a real ecu and tune it

[infamous_t]

QUESTION !!! Is it true that my fuel pump needs a consistant 12v Earth? Cause its only wired to the factory wiring, and the guy who fitted tells me the rep said he provided a replacement 040 pump..

Just to answer your question Gary, factory wiring for the fuel pump isn't up to the job.

Cable gauge is to small to carry the desired amperage, causing volt drop (which gets worse the longer the distance) , which in turn means that down the fuel pump end of things its only getting ~12V instead of the ~14V it needs to run at FULL capacty.

This setup would use a relay switched by the original pump wiring, of which there will be a diagram somewhere in here.

ps. get it tuned

[toneski]

tell me how your getting 13psi on standed ecu cause i want to do it

[KiwiRS4T]

tell me how your getting 13psi on standed ecu cause i want to do it

Bypass the solenoid and or get a boost controller (but yes, he needs a tunable ecu).