69WRX

Did a few mods to my V2 sti about 6 months or so ago.
Mods included.
Blitz nur specR decat mid and backbox.
Decat Magnex downpipe.
Megan hedaers.
Apexi induction with homemade cold air box.
FMIC
550 injectors.
Apexi pfc + commander
255lph fuel pump
parallel fuel lines
oil breather mod.
PFR7B plugs, gapped to 0.6/0.7mm.

Managed to keep the o/e fuel pressure regulator by making my own adapters.

Car was mapped and running very well indeed . made 348/330 @ scoobyclinic.
The only thing slightly strange was the injectors ( 550s ) were running @ around 96% duty cycle. I put this down to a combination of the o/e FPR and the car was mapped a little on the safe side , i.e Rich.

Anyhow, Last week started the car and it seemed to be running on 2 or maybe 3 cylinders which cleared by the time I reached the end of the street. I then noticed a strong petrol smell, which after a close inspection turned out to be the FPR adapter I made 6 months ago.

Bought myself an adjustable FPR with gauge and fitted it at the weekend which got rid of my homemade FPR adapter so cured the fuel leak. Thought this would cure the problem with the car running on 2/3 cylinders on start up as the 2 problems coincided, but car is still the same in the morning. Am now thinking its the plugs even though they have only done 4500 miles,or maybe even the coilpacks. What else could cause the car to run on 2/3 cylinders on start up ??

The other strange thing is the fuel pressure.
Set it to 3bar with the vac hose off,reconnected vac hose, tried the car and injectors hit 100% duty cycle.
Set to 3.5bar still 100% duty cycle.
Set to 4bar still 100% duty cycle.
This seems high fuel pressure to me to be maxing out 550 injectors with an o/e TD05 16G.
Shall I just keep increasing the fuel pressure untill the duty cycle comes down??
Could I have a problem with something else here?? i.e. fuel pump.

Thank for any advice you can offer

Andy

ZEN Performance

Andy,

Raising the fuel pressure will increase the flow of the injectors, but the PowerFC will not know about this, so will fuel just the same.

If you want to pop over some time, we can tweak the PFC to suit the fuel pressure of your choice. As for the cold start issues, I still don't know, your car shouldn't be any different to the many cars with PFCs fitted. The only think i can tell you is that I recently mapped a car that had what I can only describe as a "lazy" injector which would not fire for the 1st 30 seconds or so of running. Once it woke up, the engine was fine, you should be able to hear the injectors clearly by listen to them through a screwdriver (ie tip of screwdriver on injector, with ear on top of handle).

Paul

69WRX

Hi Paul.

Didnt realise the PFC would still fuel the same with increased fuel pressure, but its obvious now youve said

The cold start thing is not the same as before as it now chugs along the road on 2/3 cylinders for about 1/8 of a mile which it never did before.

p.s. thanks for the 'pop around offer' I will be in touch

mark28

headgasket, just make sure you coolent level is ok mate.

69WRX

Thats something I had not thought of....

Hope your wrong though.

rigga

iTrader: (4)

headgasket theory might have some basis in it,used to see some cars ( not scoobys) have rough running on cold start,but then would clear,turned out to be the coolant weeping into the cylinder overnight,then being cleared as the car ran...only a slight leak but enough to cause missing on one cylinder.....fairly obvious with the head off as one piston was "washed "clean compared to the others... keep a close eye on the level to see if it drps slightly