Strange Fuel Pump Issue, Help please - FIXED! Options

[flat4tom]

Hello all,

Got my 914 back together today. Here's a list of what I've done since I brought it home...

Fixed front trunk release so it will open.
Pulled gas tank. Tank is clean, no rust, fuel sock there in good shape.
Replaced all fuel lines under tank.
Pulled injectors and sent them for servicing.
Replaced all vacuum hoses.
Tightened all intake runners down - they were loose.
Removed and cleaned the throttle body
Checked the TPS and adjusted
Replaced the throttle body, installed a new TB gasket.
Removed and fixed inoperative AAR.
Replaced the spark plugs with new NGK's
Reinstalled cleaned and serviced fuel injectors.
All new fuel hoses in the engine compartment.

She runs like a top now! No vacuum leaks. No missing. Idles smooth. Took her out for a spin and to get some gas. Has a strange issue now with the fuel pump.

The fuel pump has been relocated to the front under the gas tank - recommended relocation spot. I can now hear the pump running while the engine is running. Seemed like it was quieter before... anyway...

While driving down the road straight - all is good. If I make a turn to the left the fuel pump seems to cut out (the sound changes) and the engine starves for fuel.
Right turns, no problem. (IMG:style_emoticons/default/WTF.gif) If it's idling in the driveway and I turn the wheels, no problem - fuel pressure remains constant. I wish I could check my fuel pressure gauge while driving but it's mounted to a fuel rail.

Any thought why the pump would cut out on left turns?? Any suggestions on where to look for this?

I am so close to being able to drive her!!... (IMG:style_emoticons/default/driving.gif)

T.I.A.
Tom
'73 2.0

[Katmanken]

I think vgs914 is spot on

I guess one of the questions is: did you turn the tank upside down and shake it to look for rust?

Did you bang the sides of the tank to clean out the rust and crap?

If you didn't, the installation process might have knocked some crud loose that has filled up your new fuel filter.

I went through this with another vehicle. The symptoms were: Bosch pump got louder, the car bucked during corners or bumps , and the enormous downstream high pressure fuel filter got clogged. Replaced the $30 oil can sized filter, it ran better for awhile and the noise and symptoms started again. Then the pump died. I pulled the fuel inlet hose from the pump to drain the tank and to remove the pump, and rust flakes and crap came out with the gas into my milk jug.
Removed the broken pump and more than a cup of rust flakes and crap flowed out of my new downstream fuel filter... (IMG:style_emoticons/default/blink.gif)

Resorted to in car flushes of the tank with gas until the gas was clear, a new Pierburg pump, and a new high pressure downstream filter. After awhile, the new pump got noisy, the car bucked during corners or bumps, and I found rust flakes in the intake of the pump that were stopped by a small screen filter in the pump. Bosch and Pierburg pumps are OEM pumps used interchangeably by VW on their assembly lines, and the Bosch unit lacks the filter. I cleaned the screen in the pump, and added a low pressure upstream filter that had more area than the screen and the symptoms returned. That cheap 914 look alike low pressure filter was filled with crud and replaced. This happened repeatedly until I removed the tank and hosed out an enormous amount of crud at the car wash. Banging on the tank while washing flushed more crud.

All told, it was at least SIX fuel filters, a trip to the car wash to high pressure wash the tank, and a new pump until it ran right.

While an extreme case from a load of dirty fuel with clay and gas processor pump grindings in it, the symptoms seem awfully familiar.

I'd check the filter again. Even if it was just replaced.

Good luck.