Fuel issues after installing new aftermarket upgraded fuel pump assembly
 

Hey guys this is my first post here but I’m having a weird issue. Here’s what’s going on with the car. I bought a modified aftermarket fuel pump assembly with a DW340 inside and I installed it now my car goes extremely lean (17+afr) at 3k rpm. I went a parked the car right after and sent the log to my tuner. They told me to check fuel pressure but don’t have a gauge. The car ran good with the stock pump and 660 injectors on the base map.
I’m thinking it’s losing fuel pressure while going up in the revs. Has anyone one else have issues like this when installing a aftermarket pump?



I went threw the forums and couldn’t find anyone with this exact issue

There is probably a fuel pressure leak. Also make sure you have the in-tank venturi hose plugged in so that it doesnt fuel starve with a bunch of fuel still on the driver side of the tank. Less likely but possible is a defective pump. But ultimately over the years, yes I have seen countless problems after upgrading the fuel pump, due to misunderstanding or errors in installation and setup of the new pump.