New Pump Appears to have Stopped Pumping Fuel

[starrd]

My money is on the timing belt was tightened too tight.  I too used the 45 degree method once and never again.  Almost messed up out the pump shaft bushing on one of my Diesels.  Shortly after this I purchased the proper belt tensioning tool and I have never looked back.  I always tighten my belts to exactly the same number on the gauge and I never have any problems.

[Powered by Spearco]

Man you really stuck it out. Good for you. Glad you figured it out.

I had a similiar problem, as the shaft seal was bad/ leaky. I use compressed air and shoot it at the pump seal. You can watch the air bubble come out through the feed/inlet line on pump.

[rabbitman]

How tight is your timing belt?  Overly tight and it will trash that injection pump bushing extremely quickly and cause the seal to fail in the way you describe. 

That is a very good point, using only the thumb and pinky you should be able to twist it 45*.

[Rabbit on Roids]

Hi Andy

Sitting on my Dad's couch in the UK reading about your problems.
best thing to test the pump is the "bucket test" and feed the pump seperately and the return
back into the bucket. prime the pump and then run the car on the other source of fuel
you will get air in the return of the pump for quite a while.
pumps can't make air and they will leak before they suck air unless their source is
blocked off
hope you get it running
Giles

Hi Giles, thanks for the reply and the suggests, I'm pretty sure I found the problem. After some more trouble shooting this is what i found.

- Ran the car with supply and return on a can of diesel right to the filter, car ran ok, at first the supply line had no air going into the pump, the return line eventually cleared of air after 5-10 mins of idle, but when revving the motor I would get a surge of air coming out of the return line, and no air going into the supply line of the pump. To me that points to the pump sucking in air.

- Next i pressure tested the supply and return lines, i found the sensor on top of the water/oil separator was leaking badly, ok thought i found the problem, i completely removed the separator, and re-plumbed the lines, I re-pressure tested and the supply and return lines held fairly well. Tried to run the car off the fuel tank, it would run for a while but did the same thing as the can test, surges of air on the return side of the pump.

-I went a step further and ran a brand new rubber fuel line directly from the fuel tank and to the filter, i even pulled the pick up unit and stuck the line directly in the tank so the cars supply line is completely bypassed. The car did the same thing, would barely run and still had surges of air in the return line of the pump. In this case there was absolutely no blockage of fuel to the pump.

So now i know that it is not my fuel lines, i completely bypassed them and ran the car directly from the fuel tank and tried a separate can of diesel and got the same result.

After all this i am getting large surges of air in the return line (looks like a milkshake when i rev the motor), and very little if any fuel in the supply line again leading me to believe the pump is sucking in air.

So I decided to pop off the timing cover and what did I find?

A leaking pump shaft seal. A small amount of diesel was present only on the bottom side of the timing cover, directly below the pump pulley. And I was able to reach my finger in behind the pulley and feel diesel directly below the pump seal.

So at the very least i need to get this replaced, and based on all the troubleshooting i did, this better be the solution, I've looked over the entire fuel system and bypassed the entire fuel system, that's not the issue.

Also the car runs slightly better and longer before it dies on a can of diesel, rather than pulling fuel from the tank. My guess on this is because on the can of diesel is doesn't need to provide as much suction compared to the longer run of line that is needs to pull a suction on when going to the tank.

It's just too much of a coincidence that the car ran great on the pump for 60 miles or so, died and this issue has come up, and before the new pump i never had a fuel delivery/blockage issue.

Any other comments are appreciated. 

i kinda had a feeling it was the input shaft seal. just by the way you described it. my old pump used to do exactly the same crap.

and ive never had a problem over tightening the timing belt, i just do it by hand. no spanner wrench or anything. turn the engine clockwise so the belt is being pulled tight, then push a little tension on the tensioner pulley. if i can tighten it too tight with my hands, something is wrong..

[janb]

While we are all betting   

I will wager it was a nick on the seal or shaft, not overtightened TB.

That said.... get rid of that water separator.  My A2's often give me headaches in the water separator. (and blinking glow plug lights for various reasons (bad grounds, bad connections on cluster, sick relay, no reason at all...(maybe cuz it's x-mas )).

[Doakster]

Couple responses to every ones posts.

- Water separator and supply line check valve has been removed. Rubber fuel line is now in place of those items.

- For my timing belt tension, i can use the "pinky and thumb" method and twist to 45 degrees and a little beyond that if I wish, I can't go to 90 degrees but I don't believe i had the belt too tight.

I did this exactly same procedure and tightened the belt to what i mentioned above previously when i did my timing belt 2 summers ago, and my ECO pump seal never went out on me.

But in the future, can someone give me a link to purchase a tensioning tool/measuring device. This will probably not be the last time i loosen or replace a timing belt so it will be good for my future use.

[burn_your_money]

- For my timing belt tension, i can use the "pinky and thumb" method and twist to 45 degrees and a little beyond that if I wish, I can't go to 90 degrees but I don't believe i had the belt too tight.

Sounds like you are doing it right, why spend ~$200 if you don't need to?

[Doakster]

- For my timing belt tension, i can use the "pinky and thumb" method and twist to 45 degrees and a little beyond that if I wish, I can't go to 90 degrees but I don't believe i had the belt too tight.

Sounds like you are doing it right, why spend ~$200 if you don't need to?

Well, honestly it probably would have paid for itself by now, think of it this way,


If i install a timing belt too tight, which i'm glad we agree i didn't in this case, and it possibly causes the seal to get wiped out, I have to take the time to pull the pump, send it up to you guys, which will probably be at least 2-3 weeks in down time.

Now take that 2-3 weeks and add the fuel cost of me driving around my diesel truck which gets 15mpg in the winter, and it might pay for the tension tool.

The car has been down or not running since this summer for injectors, pulled trans to get rebuilt, bad clutch, new IP, etc. etc. the list goes on, time to get this car back up and running so it can serve the purpose i bought it for, my daily driver.

Even though I think we can agree i installed the timing belt right, i'd rather spend the money on the tool and take absolutely no chances next time.

Just my thought process.

[burn_your_money]

Makes sense. I have a link on my home computer that I'll post when I get home

[Doakster]

I take it this will work for a tension measuring tool.

http://www.etoolcart.com/otc-belt-tension-gauge-6673.aspx

Also you can get a little cheap one off Ebay for $50

[Doakster]

Makes sense. I have a link on my home computer that I'll post when I get home

Thanks, I'd appreciate it.

[Vincent Waldon]

Not sure that tool will work.. at least not without some headscratching and wondering if you're getting the same readings as the VW spec.

For reference, here's what the "official" tool looks like:

http://www.vwdiesel.net/forum/index.php?topic=10275.0

Klann makes an economical version, as per the thread.

[Doakster]

Not sure that tool will work.. at least not without some headscratching and wondering if you're getting the same readings as the VW spec.

For reference, here's what the "official" tool looks like:

http://www.vwdiesel.net/forum/index.php?topic=10275.0

Klann makes an economical version, as per the thread.

Ahh thanks Vince, those are all over ebay, time to order one up, those are the cheaper ones too at $50.

[Doakster]

Also, from out of the post about using the timing belt tension tool compared to the "twist" method of checking, this is what was written.

"I believe you set the knob for the desired tension, basically the metal of the knob will stopat the desired number, then put it on the belt, and tighten the belt until the pointer matches your desired tension. The numbers on the knob are a finer scale for exact tension. At least that's what I did when I borrowed one. Doing the twist test, it was more than 45 degrees, but less than 90."

That sounds just about how I have my timing belt set right now, can go just beyond 45, but not to 90.


I'm going to use the tool on the install, and see where it puts the tension at.

[Doakster]

Bear in mind that the timing belt tension tool should be used on the timing belt while the camshaft sprocket is free to turn on the cam and the crank should have been rotated clockwise to TDC just prior to be sure there is no slack between the crank and pump.  Not following those guidelines can lead to dramatically different belt tension measurements. 

You're referring to this method being performed when the tension "measuring" tool is being used, correct?

I see you're points in cam sprocket being loose and rotating clockwise to TDC, essentially you are taking all the slack up in the belt before tensioning, and allowing tension to be taking up with the loose cam sprocket when tightening the belt.

I would think after "proper" tension is applied, rotating the motor 1 or 2 full revolutions and then rechecking with the measuring tool would give you an accurate reading and you can see if it changed any from when you first set the tension. I always do this anyway to verify the belt tracks, and recheck my belt tension is still the same.