I've got a '88 Audi 90 4cyl, (manual swap from '89 80 4cyl)

The fuel pump is buzzing really loud. Still works now but I'll replace. What's a better choice to pull from the junkyard: one from a '90 80 4cyl, one from an '89 90 5cyl, or one from a '93 90 V6? Even with the stronger V6 pump, should something else keep the fuel pressure the same and extra flow just get returned? I thought the newer V6 pump was probably the best choice.

Right now the car has some kind of fuel problem. When you go too close to wide open throttle, especially when the gear is too high and rpm's too low, the engines sputters and misses bad. If you drive the car carefully, less than 1/2 throttle, you can get around everywhere with the engine running perfect and only stumbling maybe 5% of the time. Something with the mechanical fuel distributor? Fuel pump not supplying adequate pressure?

 

Well the fuel pump might be going out ... as far as the fuel pumps go check the fuel delivery rate and also a more powerful pump may need more electricity you could be setting yourself up for problems and your cis fuel system is going to need a check valve on or near the pump usually so that your feed fuel line doesn't leak fuel back into the tank

 

the newer Bosch pumps have a rubber grip round it so less or no noise so wrap the pump with rubber to ease the vibration, my merc did that and I fitted a pump out of an Audi " same pump " Bosch

 

I agree check the rubber thingy first ... if the pump has been replaced then some one might have skipped a corner

 

Changed fuel pump and fuel distributor from a few year newer Audi 80 2.0L. Made things a little better, but still some issues. Used BG 44K fuel additive, AWESOME stuff, even better now but still some issues. Changed cap & rotor, still same. Plugs were new, waiting for wires now. Not sure what's causing the stumbling sometimes now.

 

And now won't start, runs for just a sec off starter fluid. Nothing I can do except put the old pump back on I guess, see if that fixes, get a new pump from the junkyard. No more 2.0L 80/90's, does one work off a mid 90's 2.0L VW?

 

If you're getting hessitation or a stuter response from your engine it could be your injectors or maybe even your fuel filter. If your fuel filter is clogged your fuel pump has to work harder to pump the fuel which could cause your car to not work properly.