924Board.org

[turbobob9242]

I have replaced my bosch fuel pump twice now.

Each time the thing is load as hell and doe snot keep steady pressure.

I found a new pierburg pump that is supposed to stock replacement of the bosch one. I has nice heavy outer insulation and supposed to have plastic gears rather than metal like the bosch one.

Here is the problem....

The inlet on this thing is huge. 5/8 or #10 AN size fitting. I can not find any rubber fuel hose this big.

I know that a heater hose ain't going to cut it either.

I already spent a bunch getting this setup with earls super sotck line and in line filter in front of the main pump.

Does anybody else have a pierburg and what did they use??

I was thinking about getting rid of the intank pump but don't see how that would work either.

The outlet on the gas tank is around 1/2 so there would need to be somekind of adaptor as there is at least a 1/8 diameter difference.
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Bob Ward
80 9214 turbo, w 5.3 LS V8

[augidog]

Did you replace the filter with the new pump?
Is there any debris or rust in the tank?
It sound like you have a clog if the new pump is screaming.
Maybe someone modified the fuel line.
I thought they were all 1/2 id.
I'm not sure, but there might be a screen inside the tank that could be clogged.
_________________
1978 924 95 mile daily driver.
Audi TB/POR174M/High Flow Cat/2.25" exhaust
I knew that positive thinking thing wouldn't work.

[dpw928]

I installed the 6.5 bar Pierburg in my 81 931. The inlet to the pump was the same size (10 mm?) as the tank (pump/strainer). I couldn't find a molded hose and the NA hose wouldn't work due to the placement of the pump, so I used a long generic high pressure fuel line to connect them. BTW the high pressure Pierburg allowed me to replace the internal pump with a strainer.

Dennis
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81 931 5 sp
78 928 5 sp Silver
78 928 AT Euro Black

[Paul924]

where did you guys get those Pierburg pumps? i was thinking about getting a new pump for my 924, preventative maintanince and such. are they cheap? mine is making a weird buzzing sounds. very loud at some times.

[turbobob9242]

I had totalyed cleaned out the tank a year ago. Used eastwood kit to clean it and coat it.

I will check out the screen in the tank.


dpw928...How did you get rid of the intank pump??
_________________
Bob Ward
80 9214 turbo, w 5.3 LS V8

[dpw928]

Bought my Pierburg from www.944racing.com for $139.00. To replace the internal pump, I used a 928 strainer (# 928 201 081 03). The outlet, threads, etc are identical to the intank pump. There is just a screen attached and no electrical connections. It cost less than $30.

Dennis
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81 931 5 sp
78 928 5 sp Silver
78 928 AT Euro Black

[CMXXXI]

Or, you can just "gut" the in-tank pump. On the inside of the pump, the connection from the outlet flange to the actual pump mechanism is a short length of fuel hose. If you cut the hose (or un-crimp it) and cut the internal wires, all you have left is the screw-in flange with a hole in it.

Click photo for larger image, and access to other close-ups
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'79 Eurospec 931

[turbobob9242]

I went a racing supply place that has all kinds of fuel lines from Earls.

5/8" super stock rubber hose with AN#10 fitting on one end.

AN10 to AN8 adaptor connection to an Earls microfilter.

Gutted the intank pump. It has a 1/2 outlet going to the fuel filter.

Output of filter has the 5/8 hose clamped to the Pierburg pump.

Wierd thing is the inlet of the pierburg pump is bigger (5/ but the pressure out side is smaller than the Bosch.

Hopefully this will work better now.

Thanks everyone for your ideas!
_________________
Bob Ward
80 9214 turbo, w 5.3 LS V8