Former VWDieselParts.com Forum

I use an 12v inline pump from ebay. Cost me like $14 bucks. Put a toggle switch to it so you can use it when you want, fuel pulls through it fine when off.
You shouldn't need it while it's running, but it's great for purging air and/or priming. I just used mine to drain the bottom of my fuel filter - 3 or 5 psi really helps.

I ran out of fuel one time, though it was so cool that I could get it running again in just a few minutes without endless cranking that often kills the battery. They should have made aux electric fuel pumps stock from the factory. Mercedes had a manual primer pump for their IDI engines.

I think in this case he will need the electric fuel pump while running.

Did you try a regular banjo bolt before you replace the out bolt?

Have you tried putting a clear line on the filter output and sucking on it to see how hard it is to pull fuel from the tank?

I will try a regular banjo bolt and a sucking on the clear line when I get home next week.

If the vacuum gauge is install between the filter and the pump. Where should I install the fuel pump? Closer to the tank?

Thanks in advance

I installed mine permanently, even though it's just held with a huge ziptie

I swapped out the metal screen filter for a 90 degree brass elbow so it would fit better for my application. You'll have to figure out what works for you, but gotta have some kind of filter before the electric pump or it won't last long.

Mine has extra connections but they're tight/no leaks: fuel tank, prefilter, electric pump, primary filter, then to the injection pump.

Those 100 micron prefilters (GF161) are good to have on hand, use for fueling straight out of a jug if you need to.do that as a test.

WIX makes one that is supposedly 20micron (33006) but because of it's small diameter it may clog pretty fast if you use have rust in the tank.


Mityvac to the outlet of the Inj Pump is a good way to prime the system and see how much vacuum it takes to pull fuel from the tank, but it should pull easy enough to do it by mouth (clean tubing recommended lol)

Ok guys, I am getting beat up here
I have another problem. I was hillbilly tuning to advance the pump and the pump started leaking. 1 mm adjustments. It appears to be leaking from from the bottom where the dark grey injector pump output 4 port case (that connects the hardlines to the injectors)meets the silver main body of the pump. Although a can’t actually find the leak source. I’m only seeing it dripping down below the output lines. Video shows leaking. Is there a gasket that connects the output port body to the main body.
Why would it start leaking now?
https://m.youtube.com/watch?v=BkYIh6-hg04
Also I am getting air from somewhere at the injectors. A bubble shoots upon the bypass lines in between injectors. New heat shields, new nozzles. New bypass lines.

I did clean the Out bolt. There must have been something clogging the hole because now I am getting lots of flow back to the tank.
No air between the filter and the IP.
Timing was triple checked. Flywheel lines up, camshaft tools fits correctly, and pin fits in the IP sprocket.
Felt like I was making progress then the pump started leaking.

Getting pretty discouraged. Especially since I am supposed to be driving this car around, instead I am relying on others.

SheetsC wrote: I was hillbilly tuning to advance the pump and the pump started leaking. 1 mm adjustments.

1mm nudges measured at the edge of the IP flange?

SheetsC wrote:It appears to be leaking from from the bottom where the silver injector pump output 4 port case (that connects the hardlines to the injectors)meets the darker main body of the pump. Although a can’t actually find the leak source. I’m only seeing it dripping down below the output lines.

There's a o-ring deep in there. It can be replaced, but it's a fiddly job that requires close attention and focus.

SheetsC wrote:Also I am getting air from somewhere at the injectors. A bubble shoots upon the bypass lines in between injectors. New heat shields, new nozzles. New bypass lines.

Air in those lines is common and no big deal.

SheetsC wrote: ↑Tue Nov 13, 2018 9:33 pmI did clean the Out bolt. There must have been something clogging the hole because now I am getting lots of flow back to the tank. No air between the filter and the IP.

Timing was triple checked. Flywheel lines up, camshaft tools fits correctly, and pin fits in the IP sprocket.
Felt like I was making progress then the pump started leaking.

This is all good.


You're close to success. There are pictorials on how to change the o-ring. Once that's done you can get tuning.

If that f#cking "rebuilt" pump is really leaking - not your lines or hoses, send it back for a refund!!! Adjusting an injection pump, while running or not, will not make the pump itself start leaking.

The 17mm injector line nuts do have to be loosened to take any stress off the hard lines if the pump position is moved, even just a little.

Yes 1mm movement from the pencil mark I put at the top of the IP flang.

I believe it leaking from this o ring but I’m not completely sure.
Anyone have any other links on how to replace this o-ring

viewtopic.php?f=8&t=6694

Thanks

No seals should not be leaking after a pump rebuild.

I see on the web there are techniques of using baby powder to help find leaks

SheetsC wrote: ↑Fri Nov 16, 2018 2:45 amAnyone have any other links on how to replace this o-ring?

Here's how I did mine:

I loosen the retaining screws while keeping the IP nose-down to retain the parts. I take two screws out completely. Get the head only just high enough to cut out the old ring (don't remove the head!), then I slide the new ring over with a baggie to protect the ring. The new ring will be tight. I take out one screw to get the ring past, then put the screw back in and go to the next. Sometimes I will put the spring loaded dial gauge in the timing port to keep the plunger pressed down.

More discussion here: viewtopic.php?f=8&t=5311&p=79453&hilit=gauge#p79453

Make sure it's not just an injector line nut leaking before you tear into it.

It didn’t look like it was coming out of a nut. it seemed like it’s coming from the main body bit I will loosen and retighten them to see And will investigate more when I get back home this week.

I had mine leak from the end plug (large fitting in center of delivery valves), I thought the delivery valves were leaking, very hard to tell where it was coming from. This is not the 12mm bolt for checking the timing, it's what that bolt screws into. I believe it takes a 1" box end wrench to tighten it, it's supposed to be really tight - I don't remember the psi but it's a lot.
Trouble is, delivery valves have to be removed to get a wrench on it. the copper seals of the delivery valves have to be new and the delivery valve properly torqued - they get ~2000psi of fuel pressure. Plus, to make things tricky you're working horizontal to put the delivery valve assembly back in place and everything must stay perfectly clean.

I'll say it again, that rebuilt pump should not be leaking. I rebuilt my own so when it leaked it I knew it was my fault, I didn't torque the center plug enough. If you do try to tighten the center plug it will void any warranty on that pump.

Clean the backside of the pump well, paper towels and maybe some careful shots of brake clean. Let dry. Wrap each of the four output fittings with some strips of paper towel. Secure with wire if possible. Run engine until you can detect a leak. Shut off and see if any of the paper towels are wet. You can also wrap the center plug the same way. If all those are dry and you still have a leak you may want to contact the pump rebuilder.