fuel injection pump

plumcrazee · Post by **plumcrazee** » Mon Jan 16, 2006 11:06 am

should you hear the pump running on a 412 le as i am trying to start the engine after 8 years in storage but i got no fuel to the engine. and where do you guys get pumps from if and when they go

cheers matt

raygreenwood · Post by **raygreenwood** » Mon Jan 16, 2006 12:06 pm

The D-jet and L-jet pumps can still be bought in numerous places. The stock Bosch pumps are the very best...but are very expensive. There are other brands that are quite good...and r5easonable...but the hook-ups might be slightly different. Try Walbro brand on the web.

The pump will make noise. You should not run it dry for any length of time. If the car has sat for years...remove t6he pump and clean with gasoline. Then clean out teh sock strainer in teh tank...and replace the filter BEFORE running the pump. Ray

plumcrazee · Post by **plumcrazee** » Mon Jan 16, 2006 12:09 pm

raygreenwood wrote:The D-jet and L-jet pumps can still be bought in numerous places. The stock Bosch pumps are the very best...but are very expensive. There are other brands that are quite good...and r5easonable...but the hook-ups might be slightly different. Try Walbro brand on the web.

The pump will make noise. You should not run it dry for any length of time. If the car has sat for years...remove t6he pump and clean with gasoline. Then clean out teh sock strainer in teh tank...and replace the filter BEFORE running the pump. Ray

cheers mate will have a look over the next week or so cheers again mate

MGVWfan · Post by **MGVWfan** » Tue Jan 17, 2006 9:09 am

The L-Jet pump is oh so much easier to get, and something like half the price of the D-Jet pump even new. I swapped over a few weeks ago. Here are some details.

I'm using a Bosch L-Jet pump from a Volvo (late 80's universal Swedish brick sedan). It's the one that looks like a fat silver sausage, with a banjo fitting on the discharge end that connects (via a dogbone-looking fitting) to the fuel filter, and a 12-13mm hose nipple on the suction end. Get the "dogbone" thing, the banjo fitting washers, and the locking connectors (I cut the wire as far back as I could). You'll have to splice the wiring in, or put male Faston spades on the new fuel pump wiring and figure a secure way to connect to the existing harness (I made a new harness going back to the fuel pump relay, it's not that long and I can swap back to the D-Jet pump if I need to).

Cut the nylon hose off the dogbone thing, and it's close enough to 7mm on the pump discharge fitting to allow use of 7mm FI hose with clamps. I slightly modified an old Carter electric fuel pump strap to hold it in place (the D-Jet strap is too big to hold the L-Jet pump), or use some soft iron strapping and fabricate one yourself.

You might think that 12mm hose nipple is a big deal, but late Type 2's used a filter with one end 12mm and the other end 7mm, so get a 1978 VW Bus filter at your import FLAPS. You'll know it's the right one if it's square and has a large nipple on one end, and a smaller one on the other. It'll fit where the D-Jet filter went.

Before you install the pump, it would be good to pressure test it using the correct fuel pressure regulator on the discharge end "teed" to a gauge. If you scrounge the pump from the car breakers, definitely test it before installing it. I found one bad pump before I found a nice, relatively new-looking one that worked. BTW, the L-Jet pumps appear to be quieter than the D-Jet pumps. I can hardly hear the one that's in there now.

raygreenwood · Post by **raygreenwood** » Tue Jan 17, 2006 9:15 am

Its interesting. If you have ever had a "brand new" D-jet pump...you will find that there are few pumps quieter. BUT...in order for the D-jet pump to be quiet, the vibration isolation bushings must be perfect. Technically, teh D-jet pump has better upper end pressure range and slightly more volume. But....the L-jet pump is plenty large enough to run either system with no problem.
An L-jet pump can be swapped into D-jet with some minor hose re-route at the pump. Ray

MGVWfan · Post by **MGVWfan** » Tue Jan 17, 2006 9:24 am

Greetings Dr. Greenwood!

I think the noise starts when the pump gets old and the rollers start "grumbling" (technical term), or the brushes start chattering.

BTW, there appear to be 6-7 varieties of L-Jet "sausage" pump from inspection of the aftermarket catalogs, and I only tried two (one from a BMW which was bad), so I can't vouch for every one, though the system requirements would indicate that all L-Jet main pumps should be able to produce the required flow rate and pressure.