02 Jetta was running fine and died and won’t restart

Hey guys,
So my wife took the Jetta out last night and it died and wouldn’t start again. It was 6f outside so I had thought possibly the fuel gelled in the line, although the fuel was treated with howes. I went back to it today, it’s 20f out now, and it still won’t start. I checked the fuel filter and it was almost empty. I filled it with diesel and still no start. There is a large air bubble in the clear fuel line to the pump. Am I boned? I’m afraid that the IP has died.

Sounds like your problem could be....

Your sending unit/fuel pick-up, that is in your fuel tank, has a very small orifice at a check valve that can and often will bridge/plug with debris, ice, and/or gelled fuel.
When this happens the vacuum created by the inj pump trying to suck fuel will cause air to be sucked into the fuel system at the weakest link, usualy the thermo T at the filter. This all happens more commonly in cold temps.
See....
https://www.youtube.com/watch?v=yRMTEAKsScE
If this is your problem search "ALH TDI blocked check valve in sending unit".
The check valve can be drilled out and removed.
After checking for and fixing blockage replace your fuel filter with a new one, filled with fuel, and prime the inj pump and the injectors because you will have air in the system.good luck.If you don't know how to prime the ip and injectors....search.

Also you will have to bleed the system.
If the filter hasn't been changed in a while now might be a good time.
Taking it out and to a warm place to drain it and any water that may be in the bottom.
Easiest way to bleed it is with a vacuum pump to suck fuel through the filter and injection pump.
After that you have to loosen the injector lines at the injectors and crank the engine until fuel comes out with little bubbling.
Have rags around the base of the injectors to catch the fuel.
There's posts with detailed steps if needed, search for bleeding injector pump or such.
.

Thanks guys,
I just towed it home on my trooper. Unfortunately since I don’t have a garage to work in, and it’s supposed to snow tomorrow, i’m gonna have to wait a bit to take it all apart. I’m hoping that’s all it is, but it seems logical because she didn’t make it far, and it was probably running on the fuel in the filter. I’ll keep you posted.

Definitely sounds like your sending unit check valve, reason is you said you're fuel filter was empty. That leads me to believe your issue is well before your IP.


Bajan

If the filter was nearly empty you probably have a restriction (e.g. gelled fuel, given the temperature) and the vacuum pulled was enough to open up a seal somewhere and get air into the line (e.g. at the Thermo-T on the fuel filter)

I'll be that guy, are you sure there is actually diesel in the tank?

The fuel may have gelled at 6˚. Once it gels it will stay gelled below freezing. They make chemicals to help fix the gel, but a nice warm 40˚ garage will do the trick. I'd rule that out before going thru all the fuel system. An empty fuel filter is what makes me interweb diagnose gelling.

What Bob said -- usually if the filter is empty (or has air in it even if not completely empty) you usually have a plugged fuel flow and the lift pump's suction drew air past the Thermo-T seals and into the filter.

If it's cold (below 32F) then the usual cause of that is gelled fuel -- not always, but quite frequently.

Hey guys,
So I ordered a new fuel filter and mickey clip (because it’s lost on the side of the road) from Bora Parts. When it stops snowing I’m gonna take a mityvac to the fuel line and check for restrictions. The fuel should flow relatively easy from the tank right? If it seems restricted I’ll pull the fuel pickup and drill out the check valve. Thanks for all the help and I’ll keep you posted.

KyleMillione said:

Hey guys,
So I ordered a new fuel filter and mickey clip (because it’s lost on the side of the road) from Bora Parts. When it stops snowing I’m gonna take a mityvac to the fuel line and check for restrictions. The fuel should flow relatively easy from the tank right? If it seems restricted I’ll pull the fuel pickup and drill out the check valve. Thanks for all the help and I’ll keep you posted.

Click to expand...

Yes, it should flow very easily, virtualy no resistance at all.
Even if it seems to flow easily, you may want to check the check valve anyway...if it was gelled/waxed up at that spot it may have thawed enough if things warmed up to flow again. I guess what I'm trying to say is if it was mine I'd drill out the check valve anyway as a preventitive maintenance thing.
One tip try to do it when the tank isn't full to the brim or you may get some spillage.

Hey guys,
The Hess trucks back and it’s better than ever! It finally got above freezing and I was able to dig out and work on it. I drilled out the check valve and primed the system and she fired. I didn’t change the filter as it only has 3000 miles on it and it didn’t seem damaged (no gel/water). Unfortunately now I think I killed the fuel gauge. I guess I’m gonna have to take it apart again and check the cables to the sending unit.

Genesis said:

What Bob said -- usually if the filter is empty (or has air in it even if not completely empty) you usually have a plugged fuel flow and the lift pump's suction drew air past the Thermo-T seals.

Click to expand...

The OP doesn't have a lift pump.


Bajan

Yes he does; it's in the IP itself and draws fuel through the filter.

What he doesn't have is an in-tank pressure feed pump.

Genesis said:

Yes he does; it's in the IP itself and draws fuel through the filter.

What he doesn't have is an in-tank pressure feed pump.

Click to expand...

Please shed some light on this, maybe I got it wrong. So to be clear your saying the lift pump is built into the injection pumps ?


Bajan

red16vdub said:

Please shed some light on this, maybe I got it wrong. So to be clear your saying the lift pump is built into the injection pumps ?


Bajan

Click to expand...

He must be just saying it acts as a lift pump.

KyleMillione said:

...................... Unfortunately now I think I killed the fuel gauge. I guess I’m gonna have to take it apart again and check the cables to the sending unit.

Click to expand...

I apologize, I meant to warn you. There is a small, delicate plastic lever in the fuel pick-up that is real easy to break. I did. Hope it's just a loose wire.

red16vdub said:

Please shed some light on this, maybe I got it wrong. So to be clear your saying the lift pump is built into the injection pumps ?

Bajan

Click to expand...

It is a lift pump. It's a positive-displacement vane pump in the IP and provides the fuel feed to the high-pressure side. Everything prior to the IP on the ALH vehicles is under suction.

Genesis said:

It is a lift pump. It's a positive-displacement vane pump in the IP and provides the fuel feed to the high-pressure side. Everything prior to the IP on the ALH vehicles is under suction.

Click to expand...

Ok I understand what your saying, technically it is providing both suction and pressure.


Bajan

All pumps provide both suction and pressure; that's why they're called "pumps"

Genesis said:

All pumps provide both suction and pressure; that's why they're called "pumps"

Click to expand...

I understand that smart A$$.
Usually when referring to a lift pumps relating to ALh - Tdi's on this forum, it's an in tank unit from pumpe-deuse cars.


Bajan

Genesis said:

All pumps provide both suction and pressure; that's why they're called "pumps"

Click to expand...

Actually...

Ah, nevermind. No need to go all Uber geek here.