Lift Pump for 1.9TD

[wolfsburgnut]

I've noticed on here that some people on here use lift pumps and it seems like a really good idea.  I was wondering if you could use the in tank pump assembly and pump from a gasser as it looks as though it would be a direct swap and they are dirt cheap from a wreckers as well.  Does anyone know the specs for a VW gas lift pump or if it would be suitable to use?

Thanks
Peter

[jtanguay]

hmmm most of the gasser injection systems use around 65 psi and thats from the tank  :shock:

i think some other people here thought of using gasser pumps... i'm sure there are some ones that could work though

[DVST8R]

Malone was running a stock gasser lift pump on his franken engine. The problem with the high psi is that it effects timing in the pump. Ideally you want lots of volume with only about 15psi max. So what you can do is get a pressure regulator on there and use a gasser, but I prefer just a simple holley red, cheap easy to install, tons of volume, and the right pressure. If you want some adjustabillity to your pump and a little more volume you can jump up to a holley blue.

[vwmike]

Only CIS cars run high fuel pressure and that's either 65-75 PSI or 85-95 or so if it's CIS-M. The pulse injected cars run about 40-45 psi. The Candian Golf CL pump is actually lower too...something like 1.5 or 2 bar IIRC.

[hillfolk'r]

im usin a cis pump with a 1/2 arse  regulator setup on it so i have like 35 psi or so
it drops to25-28 psi under a load
my setup is ugly,but it accomplished what i wanted
now that i know it works ill do it with nicer plumbing
you need a tee on the inlet and the outlet
one outlet tee goes to a regulator and returns to the inlet tee
the other outlet tee goes to the supply up front

i used a cheapo 10 dollar inline air pressure regulator
plumb it better with nicer stuff,this works great


pic of regulator that returns the excess fuel back to the inlet of the pump


pic of the tee on the inlet of the cis pump,with one line going back to the tank,and the other from the regulator



pic of the tee off the outlet with regulator

[wolfsburgnut]

I was kind of thinking of using the small in tank lift pump that was used on all CIS and Digifant cars.  It was attached to the sender unit and dropped down in the tank.  I kind of figured it would be a good candidate to use because it has the same part number for all the gassers whether it be 16V, 8V, G60... etc.  I just wish i knew what psi it put out, it cant be any higher than 40-45 because it was used on the digifant cars too.
here is the part number
Fuel Pump  In-Tank (VDO)  191906092G $81.00

Peter

[hillfolk'r]

i used mine cause i had it laying around
and i dont know how long itll last
because the electric terminals are almost rotted off
im not sure of the ratings on either pump
maybe hook up a in tank lift pump ,and do some flow recording

[vwmike]

I'm not sure what kind of pressure those in-tank pumps will create but to be correct they actually didn't come on all CIS cars, just those made from '85 on.

[hillfolk'r]

I am of the opinion that any appreciable pressure will muck up the timing advance curve.  I think a lift pump is a great idea, but plumb it so it will do a full circuit right back to the tank.  That way excess fuel under zero pressure is directly available to the injection pump (eliminating problems caused by resistive filters), but the pressure doesn't mess with the timing advance.  Best of all worlds, eh.

Andrew

i sat there and got out all my old notes from tech school
the return fuel being put back into the inlet is the way most every pump that has a built in regulator works
thats why i didnt make a seperate return for the bypass
and you also have plenty of feed to the pump that way too
it seems to get quicker the more psi i run to it
but i turned it down to low/mid 30s since then,and it doesnt drop more than 7-8 psi between idle and full load(a better regulator fixes this)


actually the other part of the tee that doesnt have the regulator,goes up to the filter
thats totally unrestricted
if you open the regulator itll cycle fuel all day in the cis pump
when you close it,you restrict the return side on the regulated part,and create pressure in the feed line
the part before the regulator is where the pressure is held,the regulator is just bleeding it off basically

i use a electric (digital) oil psi guage in the dash for a fuel psi guage
with the sender mounted in the outlet of the filter pad

[andy2]

Interesting that probably 100% of fuel inj shops around the world put 5 psi to the inlet of the VW ve pumps as per test specs when testing and calibrating?I would guess that even 10-15 psi would not affect much at idle or light load!

[anarchyx34]

When I did my TD swap I left the lift pump in gas tank and wired it to run anytime the ignition is on. Sure makes pump-priming that much easier. Seems to still be working fine 18k miles later.