Help Look ! Dyno Run Results - Knock/running Lean

[lilhaulerz]

Heya all,

For last week or so, i been gettin knock readings on my SAFC as high as 40-60... I ignore it figuring its only engine noise or something in drivetrain rocking as it would only get those figures once in a while.

This morning it knock to 72 and 90 !!! I was Freak out and didnt want to hurt my engine no more, this figures were hitting at approx 5500-6000rpm and i backed off.

So i book it in straight away to get a power run and air/fuel figures.

My car is following:

S1.5 R33 Skyline

Boost 10psi

Greddy Front Mount

3" Catback exhaust

SAFCII (untuned)

Copper plugs at 0.8mm gap

Pod filter and Shield

Had around 5 runs on the dyno :

First run was 220wHp @ 5000rpm - Tuner didnt want to push it as he heard knock in his knock ear phones things

2nd run was 218wHP @ 5200rpm - He tried to give it more fuel via the SAFCII i had ..+10% settings from 5500rp, onwards ( it was untune and stock settings )

3rd run was 210wHP @ 5000rpm - It didnt make much difference.. still ping and running crazy lean figures

He did One last run - And MY god was it Lean, i was holding onto my balls, like dont BLOW this f$#ker!!!

It pulled 247.4whp (180wkw) @ 6550rpm But with lean ratio of 13.0:1 !!!!

I dont know wats wrong with my car, i thought it was Rich and Retard.. BUT Obviously it not RUNNING Rich!

I think its the Fuel pump, and suggetions ???

Any info would be helpful guys!!!

Edited March 13, 2008 by lilhaulerz

[SevenAngryPenguins]

fuel pump dying in the arse, blocked filter maybe if its old, dodgey regulator maybe?? check your fuel pressures

[lilhaulerz]

Yeh i think its prob the fuel pump to, so if i check my fuel pressure , i'll be 100% sure ? where can i get this done ? or do i have to buy my own gauge ?

[VB-]

your tuner should be able to do it

[lilhaulerz]

Tru that.. Wonder why he didnt check it...

Im prob going get one of those Walbro from Slide

Im only planning to run stock turbo, 10psi and safc..

So the Walbro should be fine...

Has anyone else ever had this problem ?

i see other ppls charts running lean but its a progressive line from rich to lean... Mine just JUMPS at 5500rpm.. why ?

[SevenAngryPenguins]

walbro is more than adequate for the stock turbo, another thing you can do is bypass the fpcm (fuel pump control module) alters fuel pump voltage for different engine loads, by attaching the fuel pumps earth lead straight to ground, so the pump gets max possible voltage all the time. And if you want to take it another step further rewire the pump with a new relay and higher gauge wire straight from the battery (not really necessary though)

Edited March 15, 2008 by SevenAngryPenguins

[lilhaulerz]

Is there any side effects if i do this ? So all i do is ground it straight to the chassis or watever

[jeffworld2]

your better off not altering the wiring if its a street car, or your pump will be running 100% all the time, and this sucks for two reasons:

1- the noise! especially at idle when there is nothing to drown it out

2- the fuel will get hot, you pump so much through but it all comes back to the tank, then goes through the pump again... there are a few old threads about the " hot fuel " problems.

i would get a nismo/tomei pump too, as they are sooooooo easy to put in compared to walboro or bosch and are quieter too in my experience

[infamous_t]

your better off not altering the wiring if its a street car, or your pump will be running 100% all the time

Wrong, if done correctly with a relay, fuel pump turns on and off as per normal.

Bearing in mind that fuel pump is always running while car is running, hot fuel problems are usually cause by overkilling the fuel pump flow.

Nismo pump is a very good option as it is plug and play... but bear in mind the Nismo pump is a Bosch 023 pump.

Pump noise is either because it external mount, or incorrectly installed, or both.

Bosch is OEM for a great number of manufacturers.

[SevenAngryPenguins]

yeah i have walbro and its not noisey at all

Edited March 15, 2008 by SevenAngryPenguins

[lilhaulerz]

But is it required to mod the wiring for my mods i have ?

SAFC II ( will be tuned after pump installed )

Catback 3" ( dump pipe / cat will also be install before tune )

front mount

10psi

Pod

Aiming at 190-200rwkw

Will the stock voltage be adequate ? I dont wanna overrun my pump and shorten the life.

[Risking]

its made that amount of power due to the fact its lean.

Seriously if your watching a dyno opperator and worried about them blowing your car up ( Considering he completed that power run id be worried as well) then you should be looking else where.

If its pinging and the engine is basicly stock like you say then check the basics first. Base ignition timing, base fuel pressure etc.

If his any good he should have a flow guage and pressure guage to test the pumps output.

[Birnie]

Had a quick skim so don't know if anyone said it....

The knock reading on the SAFC is bullcrap.

Mine used to show knock and as the unit itself got hotter, the knock value increased.

I had over 100+ at one stage......on a standardish car.

[Adriano]

Wrong, if done correctly with a relay, fuel pump turns on and off as per normal.

Bearing in mind that fuel pump is always running while car is running, hot fuel problems are usually cause by overkilling the fuel pump flow.

Nismo pump is a very good option as it is plug and play... but bear in mind the Nismo pump is a Bosch 023 pump.

Pump noise is either because it external mount, or incorrectly installed, or both.

Bosch is OEM for a great number of manufacturers.

Nope sorry buddy, your wrong, the ecu varies the voltage to the pump depending on the load on the engine, to make it run quieter at idle, reduce fuel heating and increase pump life.

[SevenAngryPenguins]

the fpcm controls module alters the voltage to the fuel pump based on load from the ecu and im pretty sure it has 2 settings low and high, it has this because at light loads not as much fuel is needed so the pump doesn't pump as much fuel around to be heated by the engine bay, nothing to do with noise walbro is way louder than stock but you still have to be standing at the back of the car before you can even hear it. I only suggested that you bypass the fpcm as it maybe playing up not giving the correct voltage at high load. But if I was you id just change the pump and be done with it

maybe read this http://www.skylinesaustralia.com/forums/Fu...tml&hl=fpcm

Edited March 15, 2008 by SevenAngryPenguins

[infamous_t]

Nope sorry buddy, your wrong, the ecu varies the voltage to the pump depending on the load on the engine, to make it run quieter at idle, reduce fuel heating and increase pump life.

Wow thats interesting, thats something I wouldn't of thought they would bother with.

Still there is a solution on that link SevenAngryPenguins posted that still allows you to reap the reward of upgrading the cable to suit the new, higher load, with a different fpcm.

[lilhaulerz]

Walbro pump is on the way.. hope its the pump and nothing else...