Thread: FPR going out?

On my way home from class today I mashed it in second gear and was getting into boost and all of a sudden it hesitated for a split second, almost like a boost leak and then kept pulling hard. Driving home the AFRs were fine in and out of boost(11.2-11.8boost and 14.5 crusing) Got home and ate lunch and headed out to work and noticed I was running a bit lean and boost in second gear was kind of choking up. AFRs out of boost were fine but when I am at/close to WOT my AFRs are around 12.2-12.5 but when I am only about 50% throttle and in boost the AFRs are just fine and back to mid 11's. So I know it is not getting enough fuel when I hit full boost, it was working fine for three months before this morning. Whats going on with my car? Bad FPR? Clogged injectors? Bad fuel filter?


Setup:
DE+T at 12psi
370cc(Q45) at 3bar
Stock FPR
Walbro 255 fuel pump

You could hook up a gauge and look at your FPR to see what its at...
How long since you replaced the fuel filter and cleaned the injectors?

Planning on buying a gauge when I get home tonight, I have never replaced the fuel filter and don't know if it was replaced by the PO, injectors are the same deal, bought them off of someone here and don't know if they were cleaned or not.

It will be a great idea to replace oil filter and clean injectors out.

Give us an update when you check you FP

Also chek that the wiring to the maf is good

Would the MAF all of a sudden cause a lean condition under full boost? I'm guessing most people go for the nismo FPRs?

yes it would, if by any reason its not doing the right reading it will definetely alter the AFRs...

Yeah most people do...
I have a $30 ebay one for over a year and it holds up the pressure right where I want it...

Wow, on my way home I noticed I am a fucking idiot, for some reason I'm hitting 15psi, I'm maxing out these injectors and thats why I'm going lean under full boost.

^that was my next question, how much boost are you hitting. I've done that before

Well turns out a vac line to my boost controller split, fixed that and now back at 11.5psi. When I roll into boost my AFRs are about 11.2-11.5 and when I hit full boost it is anywhere from 11.8-12.2. Are these AFRs safe still? Also when I was running at 14-15psi it was running at no higher than 12.6 on full boost, could I have caused any damage running lean like this?

That's what I was going to say: You're maxing out the injectors.

I'd plan on upgrading those injectors REAL soon. Even at 11.5 psi you're probably damn close to max load.