IP reseal sucessfull, pump still dry overnight!

dkmc · Post by **dkmc** » Mon Oct 08, 2007 12:08 pm

I spent most of the weekend taking apart my IP (89 Jetta 1.6 NA) and installing new O rings and seals. NO more fuel leaks!
However, overnight the pump goes dry and it won't start unless I run the
Aux. elec fuel pump I installed few weeks back.
I have replaced the clear VW line from the filter to the pump with 5/16 black hose. What could be the mystery of the empty pump and line from the filter to the IP?? The only place it could possibly be going is back to the tank....

Side note: It's amazing how weird things get with the rear pump mount bolt loose.....massive vibration and strange engine RPM behavior. Gotta make sure there's a lock washer and good torque on that bolt!

dk

82vdub · Post by **82vdub** » Mon Oct 08, 2007 12:17 pm

I have been told (by a local diesel shop) that there is a crush seal or crush collar that goes bad and will allow the fuel to siphon back to the tank. I don't know if others can contribute to this or not. If that seal or collar wasn't replaced, that may be the cause for hard to start.

On the rear pump bolt, you'll find that when that bolt is loose or missing, you will flex the injector lines leading to a cracked injector line(s). Been there, done that.

Op-Ivy · Post by **Op-Ivy** » Mon Oct 08, 2007 1:07 pm

How long was your pump sitting dry for?

The vein pump that sucks the fuel into the pump from the fuel filter might have gotten stuck. That is to say, the little veins have seized and will not function properly.

I had to take the pump apart again and lube them up with some ATF. Worked like a charm afterwords.

EDIT: PS congrats on the successful reseal!

Matt

MayorDJQ · Post by **MayorDJQ** » Mon Oct 08, 2007 3:49 pm

If you run the electric FP without starting the engine, do you find any drops/puddles of fuel under the car somewhere?

Also, could the EFP be causing some restriction so that the VE pump can't prime?

dkmc · Post by **dkmc** » Mon Oct 08, 2007 8:28 pm

Ok......my replys to the comments.......

I do wonder and am now very curious about this "crush seal-crush collar" part. I looked things over pretty throughly inside as well as studied the pictures in vaughanatworld's post in the tech forum. I don't see any crush collar anyplace. I want to know if there is such in the pump and where it is located now.

My pump was sitting dry for ........never. Came off the car, onto the bench, and apart. UNLESS......the transfer pump vanes are shot.....??
I did not venture there as I had no parts to replace in there.
I maybe should have gotten a complete rebuild kit?
This pump looks to be in very good shape mechanically, IMHO.
I am no IP expert by a long shot, but I am a Machinist for 26+ years and have rebuilt a few VW diesel engines among others.

NO fuel leaks at all now.....with the AUX pump on or off. Running or not.
The electric pump was not plumbed in, and therefore could not be a restriction in the line.

NOW WHAT........????

The mystery continues......

EDIT: IF the vanes are stuck in the transfer pump, I wonder if some sort of solvent or chemical could be used to free them? I also wonder now, if the ULS diesel that has caused the O rings and seals to shrink/ leak has also caused the vanes in the Transfer pump to swell and stick in their slots in the rotor.....????

1.6D-Nut · Post by **1.6D-Nut** » Mon Oct 08, 2007 8:54 pm

"crush seal-crush collar"

Hmmm...The only thing I can think of would be the Copper Washers on the banjo bolts.
If the ones on the return line aren't sealing this COULD allow air to enter there and a siphon condition COULD result, POSSIBLY causing pump to loose prime overnight, with no external leak.
It's a stretch, I know. Just trying to help.

82vdub · Post by **82vdub** » Mon Oct 08, 2007 9:32 pm

If my memory is correct, the guy at the diesel place asked if it was hard to start. I brought the pump in for a rebuild, which was a mistake I'm only doing once. I said the car wasn't hard to start, but why? He said that there is a seal or a collar that has a crush seal that sometimes will XXX (don't remember what) and cause the pump to siphon fuel out of it. I think he was pointing at the injector line end of the pump, and probably at the center bolt area. That's about all I can say on the collar bit. I didn't pay much attention to it since I had no clue about anything regarding an IP.

A1-2-A3 · Post by **A1-2-A3** » Mon Oct 08, 2007 10:51 pm

It will probbaly be the copper washers on the banjo bolts, check at pump in out and fuel filter in and out connections, replace all of them and make sure they are tight. My car did the same thing and I noticed that there was slight fuel leakage a the filter. When it starts and the fuel pump is shut off does it idle smoothly or so you have to step it down some to keep it running. If so then its sucking air.

dkmc · Post by **dkmc** » Tue Oct 09, 2007 10:54 am

Nice new <thicker> copper washers came with the gasket kit.
No leaks from them......
I recommend the EBAY seller from Alabama that offers the kits there.
He sounded eager to help and sent the kit right out priority mail.

I will check for minute leaks in the lines. I'm sure it does not take much to break the vacuum and cause the fuel to go back to the tank.

I have to say......all the black box warnings I read and hear about the IP seem to be aimed at keeping people out of the pumps and giving more work to the pump shops. I also have to at least wonder if some of these mystery parts even exist.

I know years ago I talked with a local Diesel Shop about some minor leaks on the top cover of my first 81 Rabbit. They sure made the IP sound like a mystery machine you shouldn't lay your hands on without a signed certificate from Mr Bosch...!

I would like to learn how the IP is "calibrated" (I know it goes on a machine) but other than the Smoke Screw, what is there to adjust?
There are orifices that maybe can be changed, but not if the IP's going back on the same engine.

SO.......I guess I've fiddled with the Smoke Screw and have it running smooth and strong, so that's a Self Calibration I guess.....haha.
Cheaper to do yourself.........

Thanks for the hints, and KEEP THOSE DIESELS FLYING!

dk

Golf/Jetta · Post by **Golf/Jetta** » Tue Oct 09, 2007 3:48 pm

fuel restrictor or one way valveÂ¿?
my diesel sucks in air bubbles all the time and stays primed

libbybapa · Post by **libbybapa** » Tue Oct 09, 2007 9:11 pm

dkmc wrote:EDIT: IF the vanes are stuck in the transfer pump, I wonder if some sort of solvent or chemical could be used to free them? I also wonder now, if the ULS diesel that has caused the O rings and seals to shrink/ leak has also caused the vanes in the Transfer pump to swell and stick in their slots in the rotor.....????

The ULSD fuel is not some evil invention of the Dark Lord. It's a fine fuel and better for the environment than the previous diesel. It does not make pumps leak. A better way to look at it is that the previous fuel caused the o-rings to over-swell and then without the action of the previous fuel the o-ring shrink back beyond their previous new dimension. Resealed should last as long as it would have previously. The other issue is viscosity which can be adjusted for. I do not think the ULSD would have a particularly different effect on the vane pump. It certainly wouldn't make the metal vanes swell.

With regard to calibration there are a few other adjustments. The internal pressure can be adjusted, the governor assembly can be adjusted and the timing advance spring and shims can be adjusted to name a few. It certainly gets more complicated once the TD aneroid is added. That being said, IMO a lot of the pump mystique is not warranted, especially for the VE pump which will deliver the same amount of fuel to each cylinder despite all the fiddling you could do, unlike an inline pump. IMO the view in the rear view mirror coupled with an EGT gauge is a test bench that's pretty hard to beat. If one were to adjust the pump so that there was a similar light haze out the tailpipe throughout the rpm range while at full throttle regardless of boost pressure, they'd have pretty well nailed it.

Andrew

dkmc · Post by **dkmc** » Tue Oct 09, 2007 9:13 pm

Tonite I'm pinching shut the inlet fuel line with a C clamp..........
We'll see what happens tomorrow.........

dkmc · Post by **dkmc** » Tue Oct 09, 2007 9:22 pm

I do not think the ULSD would have a particularly different effect on
the vane pump. It certainly wouldn't make the metal vanes swell.

Oh look! The vanes are METAL not phenolic.
What the hell was I thinking......I did not study the pictures close enough!

If one were to adjust the pump so that there was a similar light haze out the tailpipe throughout the rpm range while at full throttle regardless of boost pressure, they'd have pretty well nailed it.

AMEN brother.

dk

Post by **Fatmobile** » Wed Oct 10, 2007 1:20 am

First I'd get rid of the black fuel line from the filter to the pump. 1/4" vinyl tubing is what I use.
Seeing the fuel is a great help when it come time to diagnose problems like air in the fuel.
The small line sbetween the injectors can let air in so fuel leaks back to take.
Your car should have a water seperator under the car, near the rr wheel.
There is a supposed to be a check valve near it. I've seen 2 A2 Jettas this year with a clogged check valve restricting the flow and causing air in the fuel.
A vacuum gauge will let you know there is a fuel restriction, way before it causes a problem,... but sucking fuel from the tank and seeing how fast it returns will give you an idea of how hard it is to pull fuel from the tank.
I'm guessing a clogged check valve,... but a clear piece of fuel line would be a big help when trying to figure this out.

dkmc · Post by **dkmc** » Wed Oct 10, 2007 8:33 am

Thanks, will get the clear line on there ASAP.