Problem ls1 running lean

[suey]

Hi guys I haven't recently supercharged my vu Ss with a top mount 112 magnuson supercharger and am having a problem with running lean seems to have gotten worse I did some logging with my tuner and was running good under throttle but one you backed off and was just idling it would lean out put put a bit of throttle on would go back to about 14-16 on my afr gauge. So I thought the intank pump I upgraded to a walbro 255 didn't have enough power so I brought a new walbro 400 lph intank pump and replaced the fuel filter which had some pretty dirty fuel in it and chucked a fuel pressure gauge on it to get the pressure before turning it over and was reading 60psi. So we then tried starting my ute took us ages to get it going thought because I replaced the pump and fuel filter that's why it might have taken awhile to start but when it kicked over was running even worse 17- to off the gauge on the afr gauge so turned it off straight away and pulled the injectors out the next day to take in to get cleaned and flow tested because of the dirty fuel that come out of the filter on the tank side thought may have got through and blocked the injectors and I'm running 42lb injectors. Any help would be great starting to do my head in.

Cheers
Suey

 

[Immortality]

Has it always been lean or was it all fine before when tuned?

Maybe check the fuel pressure reg.

A touch lean at idle doesn't hurt. I run the missus VS at 15.4:1 open loop idle, spends a lot of time idling so your saving just a little bit of fuel. As long as it goes rich when you step on it and the boost comes in.