Electric lift pump?

[danster]

Just wondering if there are any benefits or implications of using one. The pump in question is the OEM VAG intank lift pump from the petrol models.
As a lot of people convert petrol cars to diesel on here it may be of interest to some. I understand this pump to be a vane type that does not like being dead headed (ie little or no flow), it was designed to continually keep the fuel bath housing full for the main petrol high pressure EFI pump and thus avoid fuel starvation or air in the injector feed line.

So the question is will the Bosch VE pump have enough flow through it to avoid damaging the intank lift pump? And will the pressure the lift pump puts out have any effect on the diesel pump's internal workings due to raised case pressures?

It is simple enough to swap out the intank pump for a carb or diesel equipped sender / pick pipe unit. But I wondered if it could be of use and save bleeding issues and keep diesel pump fed with a decent amount of fuel. I understand the later PD engines use a lift pump in the tank.

[R.O.R-2.0]

Just wondering if there are any benefits or implications of using one. The pump in question is the OEM VAG intank lift pump from the petrol models.
As a lot of people convert petrol cars to diesel on here it may be of interest to some. I understand this pump to be a vane type that does not like being dead headed (ie little or no flow), it was designed to continually keep the fuel bath housing full for the main petrol high pressure EFI pump and thus avoid fuel starvation or air in the injector feed line.

So the question is will the Bosch VE pump have enough flow through it to avoid damaging the intank lift pump? And will the pressure the lift pump puts out have any effect on the diesel pump's internal workings due to raised case pressures?

It is simple enough to swap out the intank pump for a carb or diesel equipped sender / pick pipe unit. But I wondered if it could be of use and save bleeding issues and keep diesel pump fed with a decent amount of fuel. I understand the later PD engines use a lift pump in the tank.

should work just fine, the extra pressure wont hurt the injection pump one bit.. should flow enough fuel too..

the PD engines use a lift pump because they have no injection pump..

[rabbitman]

Higher IP pressure won't affect the running at all but it'll be more prone to leaks.

Maybe you could put a regulator in so it would only put like 20psi into the IP.

[R.O.R-2.0]

Higher IP pressure won't affect the running at all but it'll be more prone to leaks.

Maybe you could put a regulator in so it would only put like 20psi into the IP.

in tank lift pump on mk2 VWs is only like 5 psi..

[rabbitman]

Oh, I hardly know anything about them new gassers, I know more about the CIS systems.

He didn't say what car he's dealin' with either though............

[R.O.R-2.0]

Oh, I hardly know anything about them new gassers, I know more about the CIS systems.

He didn't say what car he's dealin' with either though............

cis has 2 pumps. the external pump being the ~100psi unit, and the in tank being the ~5psi unit.

not sure, but i think the mk3 has 2 pumps also..

[rabbitman]

cis has 2 pumps. the external pump being the ~100psi unit, and the in tank being the ~5psi unit.

not sure, but i think the mk3 has 2 pumps also..

I just looked in the bentley for CIS rabbits and they only have one fuel pump, it's external and the pressure is something like 55psi.

[BigVWman]

CIS rabbits did have only one, however mk1 bodied cabriolets started with an in tank pump somewhere around mid 84. Generally rule of thumb i used is if it had a highway spare it had in tank, if it had a full size spare and smaller gas tank it was only external pump. It is regulated to 55psi but will put out close to 100 when unregulated! Mk3s only have an in the tank no external.

[danster]

Whoops, sorry, I maybe should have clarified that a little better to avoid confusion. Yeah the intank pump is just a lift pump to supply the higher pressure injection pump that is housed in a fuel bath assembly.
Car in question is a Corrado that had a 9A 16v petrol engine originally. So KE jetronic injection. Basically the same a K jet mk2 or A2 as you call them in USA and Canada.

[R.O.R-2.0]

lift pump? thats one of those "HOLY OMG" upgrades if you ask me. dunno why i been waiting soo long.

supplying the pump with pressurized fuel helps out immensely. really helps out on the top end, but also makes it less of a dog off the bottom, it starts pulling way quicker.

and i just used one of those cheapo SHAKER pumps..

[danster]

The other thing I thought about was the bad design of plastic fitting that clips onto the oem fuel filter. Possibly pressurising that may be an issue seeing as they are bad for drawing air as it is.
Over here in the UK we can get a different fuel filter off a Rover that does away with the return from the IP needing to go back to the filter. So that eliminates any issues with that.

[R.O.R-2.0]

The other thing I thought about was the bad design of plastic fitting that clips onto the oem fuel filter. Possibly pressurising that may be an issue seeing as they are bad for drawing air as it is.
Over here in the UK we can get a different fuel filter off a Rover that does away with the return from the IP needing to go back to the filter. So that eliminates any issues with that.

mk1 filter also eliminates that issue..

[mtrans]

My practis is that electric is good only for ULSD,mehanical(petrol too) is way better for every fuel and less problem if you can conect.