New t-belt, retimed pump, car catches but wont stay running - page 1 - Troubleshooting - VWDiesel.net The IDI, TDI, and mTDI source.

New t-belt, retimed pump, car catches but wont stay running by wolfsburged on 08 Feb, 2009 16:40
Hey everybody, I just finished a massive maintenance/overhaul project and am having problems getting the car to start.

When I got the car over the summer it had been sitting for a few years. It had water in the tank and a bad glowplug relay. I was able to get it to start by filling the clear line with fresh fuel and manually turning on the glow plugs.

Here is a video of it running then:
http://www.youtube.com/watch?v=B-T3pptM7Lk&feature=channel_page

Since then I went through and did the following:
I also siphoned the contents of the tank and filled it a few times with B100 biodiesel, shook it around, and siphoned it back out to get most of the crud out of the tank.

I timed the pump according to Vince Waldon's guide. I bought the metric dial gauge and set the timing to 1.00mm exactly. I double checked this.

Now with everything reinstalled I crank the car over and it will catch and then die. It sounds good for the 5 or so seconds it runs. I do see some bubbles in the clear lines but can't seem to get them out, but again the car isn't running long enough to push them out. I've cranked it for probably a half hour total today working on this, so it should've self primed by now.

I did try to start it initially with the fuel gauge in the red. I suspect I may have pulled up some crud and blocked the fuel filter, so I will try to replace that tomorrow and see.

It wants to run more with the cold start lever pulled out. Temperature today was about 65* F. Giving it partial throttle also helped. I tried both letting the relay work and directly jumping the glow plugs, no difference.

Here is a video of it attempting to start now:
http://www.youtube.com/watch?v=lzxanwlZqUI&feature=channel
#1 by wolfsburged on 08 Feb, 2009 18:05
If the vanes are stuck, why would it have run at all before? I was able to keep it running for a short while running it off of a bottle prior to tearing stuff down for the t-belt job.

Would there be anything I could do to lubricate it or try to unstick the internals? I really don't have a pump rebuild in the budget right now and that damn tbelt/waterpump job took a good 4 months on my crazed working schedule.

What kind of lift pump are you referring to? A link perhaps?
#2 by Vincent Waldon on 08 Feb, 2009 18:45
Quote from: "wolfsburged"
If the vanes are stuck, why would it have run at all before? I was able to keep it running for a short while running it off of a bottle prior to tearing stuff down for the t-belt job.

The theory would be that gravity fed the pump when you were running off a bottle (or at least reduced the lift required)... now you're lifting fuel all the way from the back of the car and the bottom of the tank.

It definitely sounds fuel-starved. Can you see if there's a good flow of fuel out the OUT line ?

You can try filling the pump with something with lots of solvents (ATF, for example), let it soak overnight, and see if the vanes loosen... they may also loosen on their own if you can get the thing to rev reasonably well (perhaps via a bottle again).

Another possibility could be that the B100 loosened up a ton of crap that's now clogging your fuel filter ? If you apply suction on the OUT bolt (Mighty Mac or similar brake bleeder vacuum pump works well) can you suck fuel easily thru the pump ?
#3 by wolfsburged on 08 Feb, 2009 18:56
Quote from: "Vincent Waldon"

The theory would be that gravity fed the pump when you were running off a bottle (or at least reduced the lift required)... now you're lifting fuel all the way from the back of the car and the bottom of the tank.

It definitely sounds fuel-starved. Can you see if there's a good flow of fuel out the OUT line ?

You can try filling the pump with something with lots of solvents (ATF, for example), let it soak overnight, and see if the vanes loosen... they may also loosen on their own if you can get the thing to rev reasonably well (perhaps via a bottle again).

Another possibility could be that the B100 loosened up a ton of crap that's now clogging your fuel filter ? If you apply suction on the OUT bolt (Mighty Mac or similar brake bleeder vacuum pump works well) can you suck fuel easily thru the pump ?

Thanks for the reply Vince - your timing guide was infinitely helpful.

I agree that it sounds fuel starved. Tomorrow I'm going to try replacing the fuel filter.

When I primed the lines, what I did was pulled the return line from the last injector that goes back to the pump (the smaller diameter nipple, near the larger banjo fitting that is the tank return), and hooked up my Mity-Vac there and pulled vacuum.

I can pump fuel through the pump via pulling suction on that return fitting fairly easily, and in fact after a few times of that I wasn't getting many if any bubbles through.

We will see tomorrow what a new fuel filter does. If not I may try the ATF trick.

Side note: the banjo fittings at the fuel filter and the IP have copper washers under them. Are these OK to be reused, or are these crush washers that need to be replaced every time?

I think tomorrow I will try to get some clear nylon line to replace my brown and hard clear line so I can better see what is going on when I replace the fuel filter.
#4 by Rabbit TD on 08 Feb, 2009 19:11
Quote from: "wolfsburged"
Quote from: "Vincent Waldon"

The theory would be that gravity fed the pump when you were running off a bottle (or at least reduced the lift required)... now you're lifting fuel all the way from the back of the car and the bottom of the tank.

It definitely sounds fuel-starved. Can you see if there's a good flow of fuel out the OUT line ?

You can try filling the pump with something with lots of solvents (ATF, for example), let it soak overnight, and see if the vanes loosen... they may also loosen on their own if you can get the thing to rev reasonably well (perhaps via a bottle again).

Another possibility could be that the B100 loosened up a ton of crap that's now clogging your fuel filter ? If you apply suction on the OUT bolt (Mighty Mac or similar brake bleeder vacuum pump works well) can you suck fuel easily thru the pump ?

Thanks for the reply Vince - your timing guide was infinitely helpful.

I agree that it sounds fuel starved. Tomorrow I'm going to try replacing the fuel filter.

When I primed the lines, what I did was pulled the return line from the last injector that goes back to the pump (the smaller diameter nipple, near the larger banjo fitting that is the tank return), and hooked up my Mity-Vac there and pulled vacuum.

I can pump fuel through the pump via pulling suction on that return fitting fairly easily, and in fact after a few times of that I wasn't getting many if any bubbles through.

We will see tomorrow what a new fuel filter does. If not I may try the ATF trick.

Side note: the banjo fittings at the fuel filter and the IP have copper washers under them. Are these OK to be reused, or are these crush washers that need to be replaced every time?

I think tomorrow I will try to get some clear nylon line to replace my brown and hard clear line so I can better see what is going on when I replace the fuel filter.

Why not fill the new filter with ATF at the same time.
#5 by jtanguay on 08 Feb, 2009 19:34
running a can of diesel purge through the pump might be a good idea...
#6 by wolfsburged on 08 Feb, 2009 19:53
Forgot to mention that I've already dumped a can of LubroMoly Diesel Purge into the tank.

Could this simply be an air pocket type of issue? Again, there are some bubbles in the lines it seems.

And if I decide to do the ATF thing, should I just fill the filter and crank it until its gone through the pump and let it sit, or keep trying to start the car? How much should go through the pump, and how long should I keep it in there?

Hoping tomorrow that with clear line and a new filter I can get some more ideas as to whats going on.
#7 by Vincent Waldon on 08 Feb, 2009 21:32
Quote from: "wolfsburged"

Side note: the banjo fittings at the fuel filter and the IP have copper washers under them. Are these OK to be reused, or are these crush washers that need to be replaced every time?

Well, they are supposed to be a 1-time thing, but even me, Mr. Fastidious About Such Things, tends to re-use 'em till they leak. Being copper they are pretty soft, and I generally take it easy when torquing them down so that they can be reused with a bit more torque the next time. You can also heat 'em red hot with a propane torch to re-soften them.

Quote from: "wolfsburged"

I think tomorrow I will try to get some clear nylon line to replace my brown and hard clear line so I can better see what is going on when I replace the fuel filter.

Probably a good idea... handy in the future too.

I was thinking that if all else fails you could try running it from a bucket again. If it runs markedly better you've pretty much eliminated timing, injectors, etc, and can focus your attention on the IP.... specifically the vane pump.
#8 by fatmobile on 08 Feb, 2009 22:06
Did you back out the max fuel screw for any reason, then forget to screw it back in?
Crap can clog the screen on the intank pickup also,.. and sometimes the check valve by the water seperator, under the car.
Once you get clearer fuel lines; see if the air bubbles in the line are moving while the car is cranking,.. if they are the vanes are fine.
#9 by LoneWolf on 09 Feb, 2009 00:37
i had a similar problem with a pump for my AAZ, i ended up buying a small inline hand pump (squeezy bulb) to force the pump to take fuel. its now a permanent feature in the fuel line, really useful for re-bleeding the pump if i have to work on it again :wink:
#10 by wolfsburged on 09 Feb, 2009 06:38
Quote from: "fatmobile"
Did you back out the max fuel screw for any reason, then forget to screw it back in?
Crap can clog the screen on the intank pickup also,.. and sometimes the check valve by the water seperator, under the car.
Once you get clearer fuel lines; see if the air bubbles in the line are moving while the car is cranking,.. if they are the vanes are fine.

Have not touched either the fueling or idle screws at all.

Can you visually inspect the screen through the fuel sender opening? Right now it's over half a tank so I can't see anything in there...

We will see what happens with clear lines today.
#11 by Vincent Waldon on 09 Feb, 2009 08:54
Quote from: "wolfsburged"

Can you visually inspect the screen through the fuel sender opening?

As luck would have it the fuel sender / pickup are one integrated unit and are what plugs the hole in the top of the fuel tank... so they'll come out as one unit for inspection.
#12 by wolfsburged on 09 Feb, 2009 09:54
Quote from: "Vincent Waldon"
Quote from: "wolfsburged"

Can you visually inspect the screen through the fuel sender opening?

As luck would have it the fuel sender / pickup are one integrated unit and are what plugs the hole in the top of the fuel tank... so they'll come out as one unit for inspection.

A bit confused - we are talking about the level sender with the float right?
http://www.germanautoparts.com/images/7607a6e2a4135303931393137313/s

Where is the filter on that?
#13 by jtanguay on 09 Feb, 2009 10:04
Quote from: "wolfsburged"
Quote from: "Vincent Waldon"
Quote from: "wolfsburged"

Can you visually inspect the screen through the fuel sender opening?

As luck would have it the fuel sender / pickup are one integrated unit and are what plugs the hole in the top of the fuel tank... so they'll come out as one unit for inspection.

A bit confused - we are talking about the level sender with the float right?
http://www.germanautoparts.com/images/7607a6e2a4135303931393137313/s

Where is the filter on that?

is that for a mk1 jetta? the in tank screen could be really clogged from the biodiesel cleaning out the tank.

seems like you could really solve a lot of diagnosing nightmares if you just ran the car off a known clean tank of fuel (get a small jerry can of good diesel fuel and get it to run off that. if she runs good, then you know your fuel system is bad and needs to be fixed)
#14 by wolfsburged on 09 Feb, 2009 11:01
1984 Jetta GL TD.