Fuel pump replacement

[dougie30]

Ok so I have a 86 325e with the in tank and external fuel pumps and one of them is shitting the bed (maybe bolth).

Ill be driving at a stedy pace going 65 at 3k and my car will bog out and then pic back up. It does this quit a bit and I hear a loud buzzing comi g from near where my ful pump is located.

So I was wondering which one would be causing this? I know the internal one pumps the fuel but im not sure about the external how it works? Maybe this one could be slowly dying out?

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[dougie30]

Or would it just be easier to replace bolth pumps with the walbro 255 intank one?

I was reading up on this and it seemd fairly easy im hust not sure what I should to about the external pump?

Just use a duel barbed fitting inplace of it?

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[jlevie]

The noisy pump is almost always the external high pressure pump. It will make noise if worn or if it is having to work too hard from a clogged filter or dead in-tank transfer pump.

[dougie30]

Just went to auto zone and they said the internal pump is 149$ with the whole assembly and the external is 150$ im not sure wich one I should get what is the best way to test them?

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[TobyB]

I like the in- tank conversion myself, but just because it's easier to service. Converting IS
a big pain, because you have to replace and re- route the pressure and return(?) lines.

The way to test them is to put a fuel pressure gauge on it.

But you can test the in- tank pump by unhooking it and letting it dump into a coffee can- if you get a healthy flow of fuel, it's OK. You have to crank
(on some (most?) cars)
to get the pump to run.

And I'm with Jim- check for junk in the screen and tank and replace the filter!

hth

t