So, today, we are going to learn how to upgrade your dieing or otherwise insufficient stock fuel pump in the Audi B5 chassis car.
I procured the FP from GermanAutoSupply.com for $185 shipped
The Audi V8 Basket(895 201 779 H) and Strainer(895 201 531 A) came from World Impex Inc. These 2 parts weren’t cheap -at roughly $150 shipped for both pieces.
I purchased the 12mm Banjo fitting w/6mm nipple from eBay – a.e.auto for $9.60 shipped
I bought the M12 and M18 copper washers from my local Oreilys auto store. I can’t remember the price, it was reasonable though.
The M18x1.5 adaptor was procured from Verocious Motorsports @Amazon.com for $15 shipped.
The Porsche Fuel Check Valve Cap Nut came from the seller – classiccarsandparts @eBay Paid $7.70 shipped.
You’ll need to start out by removing the little screened vent piece that only the OE V8 pump would utilize. I got most of it with a sharp electronics type side cutters, then finished the job with a large x-acto knife.
Now the pump should slide in with only slight friction. The bottom has a nice little recess that is perfect for suffing soft PVC tubing into, to secure the fuel pump in place so that it doesn’t move around.The 1/2″ soft PVC tubing came from a Mityvac Fluid Transfer Pump that died, so I had this stuff at my disposal.
I would use soft PVC over nylon tubing for this job. I opted to cut the soft PVC hose in half lengthwise, then, tuck in into the bottom of the pump -as shown in the following picture.
The inlet of the 044 fuel pump is a threaded m18x1.5 connection. Upon strainer fitment; I noticed that the pump inlet sat much higher in the basket strainer, and decided to use a modified aluminum adapter to put the sump down to it’s proper level in the strainer.
You can see that I simply hacked off the -10 AN side of the adapter, and screwed it into the FP with an m18 copper washer. That gave me 5/16″ clearance between the sump, and the bottom of the strainer.
If you look closely at the following picture; you can see the added benefit of the extended sump location.
The strainer itself fits into 3 prongs on the basket, and locks by turning the strainer clockwise.
So now that we have the assembling of the new pump out of the way; it’s time to take out the old pump.
I made the custom fuel pump unlocking tool out of 1/4″ plated steel rod and a good ‘ol Vise grip. You want the outside legs to be about 5″ long, with 3 1/8″ center spacing between them, and 13″ or so extension length. You’ll need to angle the extension rod out slightly – roughly 98 degrees from forks, because the fuel pump tucks back in the tank rather than directly below the access hole for the tank. You’ll understand better when you see it lol. Alternatively, if you live in the Twin Cities; you can borrow my handy dandy homemade tool when you tackle the job.
I’m not going to document the whole process of removing the old pump, as this information is pretty well easy to find on teh intrawebs already.
Here are some pictures of the stock FP verses the massive Bosch 044 assembly:
You’ll need an Oetiker stepless clamp 10.9mm size -for clamping the poly tubing onto the FP nipple. 1 is fine; I decided to use 2 of them since there was plenty of room for 2, and I like the added peace of mind.
Here’s a picture with the level sensor in place, so that you can see the importance of the outlet orientation.
One last picture of the connections under the cover, before it’s buttoned back up.
One side note of importance: The polarity is different from the stock pump, and the Bosch. The large electrical lug on the stock VDO pump is for (-) small for (+). On the Bosch: Large lug is (+) and small lug is (-). I didn’t realize this at 1st when I was soldering new terminals on the Bosch pump. I ended up swapping the terminals at the plug because it was much easier than resoldering connections at the pump. This route is fine, unless I put a stock pump back in, and get baffled as to why I don’t have any fuel pressure, lol.
I’ve been running this pump for over a month now, and can say that it’s surprisingly quite for such a big pump. It is noisier than the stock pump, but, it’s really not that noticeable. 🙂
Source: http://forums.quattroworld.com/a4/msgs/85051.phtml – By n0yxl