Having some fueling issues, not sure exactly what the cause is. Trying to get some feedback if anybody has any ideas. Turbo k20 in an eg. Running a walbro 400 on the stock hanger, ID 2000s and e85. When my tuner was running the car on the dyno, it started running lean below a half tank of fuel. Added fuel in kpro and did nothing. Kept adding fuel and kept running lean. Car on high boost was only at 60% duty cycle for fuel. Added 5 gallons of fuel and all the fuel he added came into play and started running super rich. On the street it's the same thing. Just below half a tank, it acts like its running out of gas, sputtering, ect. I know the sending unit is reading correctly cause when I fill it up, it only takes like 4 or 5 gallons. Pulled the pump out of the tank and everything still looks fine. Not sure if something is wrong with the pump maybe? Any input would be great. I ran the pump with pump gas a couple seasons ago and it never had a problem. Runs great above half a tank of fuel.

 

I know U already said U pull the pump back out but did u inspect the rubber hose? mine was busted and I was wondering why I wasn't getting pressure.

 

Are you monitoring fuel pressure in anyway? Is this the E85 compatible version pump?

My last "450" started to not hold pressure above waste-gate boost when I tuned it on the dyno. Ended up having to buy a new pump, never really opened it up to see what was wrong, but the new pump was much better sounding.

 

How long did your 450 last you? And what pump are you running now?

 

3 Years, and replaced with same pump.

 

Didn't look at the hose super close. Looked intact when I had the pump out, but I'll check again. Car runs great with a full tank of fuel at any boost level so I doubt pressure is dropping out. The gauge is under the hood so I can't keep an eye on it other than at idle. Pump is e85 compatible. Not sure whether I wanna try a new pump or just wait and sump the tank and run an inline pump for next season.

 

My car would do the same, It will start leaning out after about under half tank. I'm on e85 daily driven NA setup though.

 

did you put in a stock length sock, the one that comes with these pumps are too short.

you will have fueling issues like this if not addressed, also look and see if the oem rubber fuel lines are not swollen on the inside ans restricting flow.

 

It's been a while so I don't remember if I reused the old sock or used one that came with the pump. And I'll check the hose this weekend. Thanks for the input