Losing Fuel Pressure After 4k RPM??

[Mo87NA]

What's going on guys? I've got a "Walbro" I purchased off ebay. However, I'm starting to think it might be a cheap knock-off that went bad. Over the past two weeks it has gotten extremely loud. I can hear it a good 50-75 feet away. I also noticed I can't rev past 4k rpm without running extremely lean and my fuel pressure dropping to about 10 psi. I'm only boosting 7 psi on my new set-up.

Do you think my Walbro actually took a shit on me, or do you guys think it's something else. I'm also running 680 cc injectors.

Mo

 

[TurboStreetCar]

sounds like it. loosing fuel at stock boost level seems a little strange.

 

[Mo87NA]

Well its not a stock turbo. It's a Frank 5 Greddy 20g.

Mo

 

[TurboStreetCar]

i find it strange because the overall fuel pressure at full boost is still about stock pressure as long as you havent adjusted it much. what is your base fuel pressure? are you still on stock regulator?

 

[lagged]

get a twin turbo fuel pump.

 

[Mo87NA]

I've been doing some reading and I've decided to go with the Mk4 pump. Is the install much different from the Walbro?

Mo

 

[RacerXJ220]

Check everything.

All the lines for kinks.
Replace the fuel filter?
Stock fuel pressure regulator?

 

[ViR2]

I think this is what u bought
http://fuel-pumps.net/walbro-forgeries.html

Do not buy such parts from e-bay...

 

[Mo87NA]

I think you might be right. I should have known better. The fuel filter was just changed and I'm running an Aeromotive AFPR. I doubt there's a kink in the line cause the fuel pressure is fine at idle and below 4k rpm.