Start with Briano1234's in-tank
pump replacement write up to get you into the tank and the old
in-tank pump removed.
1984.5-1993 mk1 How to change your in-tank
removed both the in tank pump and external pump from my '92
replaced both with a Chevy in tank pump and a Dodge Truck fuel
mounted under the hood.
ALL the external stuff around the main pump is gone, including
the accumulator/reservoir thingy.
there are no baffles inside the tank and there is no longer an
accumulator to keep supply to the main pump inlet, it will
hard cornering and below 1/4 tank. I may retrofit a CIS
address the starvation issue. (This also told me the stock in
must also starve during hard cornering with low fuel, since the
accumulator keeps fuel available to the main pump inlet, the
The starvation is self correcting, the cornering
speed simply drops until fuel gets back to the pump. I don't
hard often enough to care. I used to.
As currently installed,
the pump is considerably noisier than the factory set up,
I'll pull it back out and fine tune the fit up.
I did pull it back
out and installed the Aitex supplied rubber noise damper sleeve,
the last pic. I also put the origial VW pick up screen on, it
perfectly. The Chevy screen was a bit of a beach to wrangle in
Chevy pump has a built in check valve, no worries on that score.
out a quart in about 22 seconds, factory pump takes about 30
Pressure is regulated by the fuel pressure regulator, I didn't
I did have to crimp one connector, solder one
other. I had to shorten the pipe on the fuel level sender to get
fit, the Chevy pump is a little longer. Shortening included
the hose barb, or flared end, the Chevy pump had no barb either,
figured it wasn't really needed, there's no place or room for
to blow itself off of the fitting.
The pump I used was an Airtex E3240, I used a WIX 33321 fuel
Chevy pump comes with a connector kit of a sort, there's plenty
with. [u]The Chevy GROUND IS BLACK!!![/u] Totally Bassackwards
what we are used to with VWs where black is power, brown is
you yank the hoses, stuff a 'leader' wire well inside each, I
gauge. Pull the hoses with wires out through the bottom, remove
accumulator with the hoses as a unit. Follow the new hoses up
leader wires. It was pretty easy reaching top and bottom sides
same time by myself with just one jack stand under the right
There is one spring clip on the leading edge of
the tank you'll have to deal with, it holds a hose. I pried,
and pulled on it until it was finally mutilated enough to remove
left it out and still sleep easy. It was holding either 6 or 7
layout pic below, the clip itself is similar to 34 in the vent
I initially used the stock fuel filter, didn't even
have one to change. I had planned on an underhood mounted
filter, so I
left enough hose between the sender and the stock filter inlet
could re-route from the sender directly to the main feed line
stock filter was removed.
It's been in the car for at over a year, probably 15,000 miles
or more, no other issues besides what's already been mentioned.
that Airtex pump part number, compare to the the cost of
stock DigiFant pumps, you'll know why I went this route. I think
WIX filter I used is considerably less than OEM too.
approximately a quart in 30 seconds is the stock in-tank pump's
what it is expected to pump. If a stock pump can't pump that
it's due for a dirt nap.
You know that while plastic
accumulator/reservoir in-line between the in-tank and main
the in-tank pump has to do is keep that accumulator/reservoir
that the main pump can draw from that accumulator/reservoir.
accumulator/reservoir has four hoses, the output of the in-tank
the inlet for the main pump, return flow from the fuel
regulator and return flow into the tank. There are no valves or
anything else inside except for a slight restriction in the
to the tank.
The in-tank pump pumps rather freely with little
restriction into the accumulator/reservoir, excess in-tank pump
goes to the back tank, in-tank pump pressure build up is avoided
relieved) via the return line to the tank.
Stock, all the
in-tank pump and the accumulator/reservoir do is to keep fuel
to the main pump especially during hard cornering with less than
tank when the in-tank pump starves, there being no baffles
inside an A1
(or I think A2) tank.