Fuel pressure issue I'm stumped

[WannaBe30]

So I'm I'm stumped I hope someone can help me out or at least tell me a few more things to check

This is a tuning swap I've had it up and running for a while and this issue has been off and on from the beginning.

On first start up everything is normal sometimes (most the time). After driving around for a whole my fuel pump starts whining loud. When I did the swap the pump was replaced after the swap it started and I figured I got a bad pump and returned it for another no go.

I also changed the fuel filter and a week ago changed it again.

Before that I took a guess at the fuel pressure regulator and that seemed to help till the second day.

I'm stumped when I give it half throttle when the pump is whining it seems to surge or feel like the power is off and on but if I stomp it most the power is there not all tho

This is an s52 obd1 with a chip stock injectors big maf in an 89 325i

Help please sick of losing power.

[Andy.B]

You might have sediments in the fuel tank that are clogging up the fuel pickup strainer. When the car is off, the pump stops sucking in fuel, and the sediments will settle to the bottom of the tank, but when you drive, they get mixed up on the fuel, and start clogging the strainer, cutting off fuel supply, and putting an extra load on the fuel pump.

[WannaBe30]

I completely agree but I don't think this is my issue. I have opened up the tank and checked the filter sack on the pump.

I really think this is more of a pressure after the pump than before but I will pull the pump again to check

Just out of curiosity if the chip I have is for 21 or 24 pound injectors but I have stock injectors could this be a side effect? The guy that I bout the chip from said this was for stock injectors ews delete and larger him with stock injectors but I know my car is running very rich I get some awesome backfires

Thanks for the speedy response Andy

[justin_l_]

Put a fuel pressure gauge inline and monitor it.

[WannaBe30]

That's not fun cause I don't have one. :(

[The Jack]

What do stop injectors run at? I guess if the chip doesn't match up with your injectors it won't run properly. Maybe the guy got the software mixed up?

[WannaBe30]

Figured it out :) glad it wasn't too big of pain in the A

Sediment in the gas tank was clogging the sock on the pump.

Dropped the tank had it professionally finished and she's a power horse again :)

[Andy.B]

You might have sediments in the fuel tank that are clogging up the fuel pickup strainer.

I completely agree but I don't think this is my issue. I have opened up the tank and checked the filter sack on the pump.

Sediment in the gas tank was clogging the sock on the pump.

Dropped the tank had it professionally finished and she's a power horse again :)

Nailed it ;)

Seriously though, I'm glad you got it repaired and it was relatively painless. I know I need to do the same thing on my car, and I have been putting it off until I have a new clutch and driveshaft guibo, to make pulling everything out as efficient as possible.