2003 Jetta TDI injector pump bad?

aikway

Member
Joined
Apr 13, 2008
Location
florence,alabama
TDI
2003 jetta wagon 1.9
Suddenly my Jetta won't start. No fuel showing when cranked with injector line fitting open a half turn? Fuel filter new and full of fuel. How do I determine if the fuel injector pump is bad? If the pump is dry, do I need to prime it? What else would cause no fuel at the injectors if fuel lines are clear and the fuel filter is OK?
 

TornadoRed

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Aug 3, 2003
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2003 Jetta TDI wagon, silver; 2003 Jetta TDI wagon, indigo blue; 2003 Golf GL 5-spd, red (PARTED); 2003 Golf GLS 5-spd, indigo blue (SOLD); 2003 Jetta TDI wagon, Candy White (SOLD)
aikway said:
Suddenly my Jetta won't start. No fuel showing when cranked with injector line fitting open a half turn? Fuel filter new and full of fuel. How do I determine if the fuel injector pump is bad? If the pump is dry, do I need to prime it? What else would cause no fuel at the injectors if fuel lines are clear and the fuel filter is OK?
I would suspect air is leaking into the fuel filter through the thermostatic-T.

Replace the O-rings, make sure they are "fat" enough to make an air-tight seal.

Edit: Re-read your post, if the fuel filter is full then air is not entering via the thermostatic-T.
 
Last edited:

mrGutWrench

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Aug 29, 2002
Location
Carrboro, NC
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'03 Jetta Wagon, 5-speed, 563K Miles (July '23)
__. There are a couple of different "primes". One is the prime that gets fuel into the pump. If ithe pump is dry, you need to put a MityVac (or similar) on the fuel return pipe (the one that goes to the Thermo-T). Pull a vacuum and you'll soon see bubbles coming up, keep on until pure liquid fuel comes up.

__. Once you've primed the pump, you need to prime the injectors. To do this, loosen the big nuts (I think they're 17mm) on top of the injectors about 1/2--3/4 of a turn. Then crank the engine, in about 5-7 seconds you'll see fuel squirting out of the injector with the shortest line to the injector. Once you see this, tighten up that cap nut. Then you'll see another one squirt in a few seconds, etc. It may start to "kick over", at that point tighten up the remaining cap nuts.

__. If it doesn't start after all this and the pump is dry again, you have a bigger problem .... gelled fuel, frozen tank pickup, leaking "O-ring" on the Thermo-T, or bad pump. But usually a bad pump will continue to pump a little; it may be at the wrong time or low pressure. A pump that doesn't pump *anything* and is totally dry usually isn't a dry pump, it's usually another problem. But these are complicated systems and you have to do a thorough, logical troubleshooting sequence.
 

JETaah

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mi 48836
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96 B4V, 1999.5 jettaIV,2005 BEW Beetle
runonbeer said:
A leak at the pump head would not draw air into the system, would it?
Under operating conditions the case is under pressure and a bad pump head seal would would cause fuel to leak out but not air in.
On the other hand a bad seal on the shaft right behind the pump's pulley hub may cause air to be drawn into the pump without necessarily leak fuel out (so said Mark at DFIS in Portland). Unfortunately the pump repair seal kits that are commonly available don't include this one.
 

runonbeer

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In my experience, a head seal does not necessarily have to be leaking fuel externally to cause a loss of prime. Air can creep in past the seal and displace all of the fuel back to the tank. I'm not sure how this works (since there is nothing like a dip tube inside the pump) but I have seen it happen. Indeed, once you attempt to re-prime the pump with a vacuum device, you will find that you are pulling air across the seal instead of pulling fuel from the tank into the pump. Usually, as I've said before, you get "one last chance" to reprime a pump that has lost prime due to a head seal failure before you are unable to prime on subsequent attempts. At this point, one must replace the seal before the pump can be primed (or use a non-vacuum device, i.e. a hand pump/primer bulb).

the main shaft seal on my car has been "weeping" for a significant amount of time. It has not gotten any worse in the last 3 years and I have never experienced a loss of prime on my car outside of the time that my head seal failed (no evidence of an external leak when it happened). Lucky for me, I'm me so I just stuck a new seal in there and moved on with my day.
The main shaft seal leak is not really a big deal in my opinion (outside of aesthetics) and I tend to ignore it. Pump removal is required to repair a "weeping" shaft seal.
 

jetta 97

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JETaah you are right . Head seal won't do that. I had car it was pouring fuel at pump head and it will start normal.
I would said check voltage on shut of valve . You will have 11-12V for few seconds when you turn ignition on ,so you must do this with some one in car and you checking.
Also do you get glow plug light on dash? You my have bad 109 relay.
 

Franko6

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ANY leak, from the filter, to quick couple lines, to the seals can cause fuel to leak back to the tank. However, if the filter is full when you remove the 'T', that is not likely the culprit.

Certainly, the first step is to make sure the fuel shutoff is operational. It should click when the key is moved to the ON position. If not, the next thing to check is the 109 relay. They are historically one of the problem-makers

The fuel can displace back to the tank any time there is an air leak. The tank is the low point and the lines become a siphons. There is supposed to be a check ball in the fuel lines, but they don't always work. So, fuel can siphon from either the fuel feed line or the fuel return line. The return line ball check is in the right direction for siphoning already. All it takes is an air leak.
 

Franko6

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Jetta, 99, Silver`
ANY leak, from the filter, to quick couple lines, to the seals can cause fuel to leak back to the tank. However, if the filter is full when you remove the 'T', that is not likely the culprit.

Certainly, the first step is to make sure the fuel shutoff is operational. It should click when the key is moved to the ON position. If not, the next thing to check is the 109 relay. They are historically one of the problem-makers

The fuel can displace back to the tank any time there is an air leak. The tank is the low point and the lines become a siphons. There is supposed to be a check ball in the fuel lines, but they don't always work. So, fuel can siphon from either the fuel feed line or the fuel return line. The return line ball check is in the right direction for siphoning already. All it takes is an air leak.
 

aikway

Member
Joined
Apr 13, 2008
Location
florence,alabama
TDI
2003 jetta wagon 1.9
Fuel injector pump bad?

I put a mityvac on the fuel filter and got good steady fuel, then when I try to pull from the return line off of the pump, I get a little fuel in the line then it stops???
Aikway






mrGutWrench said:
__. There are a couple of different "primes". One is the prime that gets fuel into the pump. If ithe pump is dry, you need to put a MityVac (or similar) on the fuel return pipe (the one that goes to the Thermo-T). Pull a vacuum and you'll soon see bubbles coming up, keep on until pure liquid fuel comes up.

__. Once you've primed the pump, you need to prime the injectors. To do this, loosen the big nuts (I think they're 17mm) on top of the injectors about 1/2--3/4 of a turn. Then crank the engine, in about 5-7 seconds you'll see fuel squirting out of the injector with the shortest line to the injector. Once you see this, tighten up that cap nut. Then you'll see another one squirt in a few seconds, etc. It may start to "kick over", at that point tighten up the remaining cap nuts.

__. If it doesn't start after all this and the pump is dry again, you have a bigger problem .... gelled fuel, frozen tank pickup, leaking "O-ring" on the Thermo-T, or bad pump. But usually a bad pump will continue to pump a little; it may be at the wrong time or low pressure. A pump that doesn't pump *anything* and is totally dry usually isn't a dry pump, it's usually another problem. But these are complicated systems and you have to do a thorough, logical troubleshooting sequence.
 

mrGutWrench

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Aug 29, 2002
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'03 Jetta Wagon, 5-speed, 563K Miles (July '23)
aikway said:
I put a mityvac on the fuel filter and got good steady fuel, then when I try to pull from the return line off of the pump, I get a little fuel in the line then it stops??? Aikway
__. Do you mean that it pulls a little fuel and then the fuel stops but it starts pulling air instead????
 

rackaracka

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Nov 15, 2001
Location
Monroe, NJ
aikway said:
I put a mityvac on the fuel filter and got good steady fuel, then when I try to pull from the return line off of the pump, I get a little fuel in the line then it stops???
Aikway
When it "stops"... Does it hold vacuum? If so, be patient.. It'll burp, air will flow and then you will get fuel (If all is well). You'll probably get foam for a while, followed by smaller bubbles, followed by clear fuel. Also - just to verify that you're doing it right... You need to plug the return line that you've pulled off of the IP, and pull vacuum on the IP nipple.
 

runonbeer

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or just pull vacuum on the cloth wrapped return line to the #4 injector. So much easier, I don't see why everyone always wants to prime it at the big line:confused:

Pull the line off the injector and connect the mity vac. Start pumping if you immediately get a bunch of bubbles in the line then you're probably just pulling air in across the head seal. seen it 100 times!
 

Burky

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Dec 27, 2016
Location
Columbus, Ga.
TDI
2003 VW Jetta
'03 Jetta TDI Injection Pump issues

Hey guys, I know this thread has been around for a long time now, but I have some questions about my '03 Jetta injection pump. My pump was leaking real bad, so I found the videos uploaded by "Runonbeer" http://forums.tdiclub.com/showthread.php?t=287336&highlight=video and followed his instructions to a T. I cranked the car up and set the IQ to 3.5. I drove the car around for several miles to make sure it was running right, and it was. The next morning I decided to drive it to work, 12 miles. After driving 11.5 miles with no issues at all, the car started cutting out on me. I barely made it into work. The car was running, but like on limp mode, 5 mph.

After work it was very hard to crank. After several tries it finally cranked up, but I had to keep it above 2000 rpm or it would cut off. I was able to limp the car home and put it in my shop. For the last 3 weeks I haven't been able to crank the car up. It just spews white smoke out the tail pipe and doesn't even try to crank. I have checked everything except fuel pressure. Hooked it back up to the VAGCOM and it is reading 4.0.

Today Dec 26, 2016 it finally decided to crank up, but I have to keep it above 2000 rpm or it will cut off. The car has 203,000 miles on it. It was running fine before I replaced the 3 gaskets/seals on it.

Any suggestions would be greatly appreciated. Thanks.
 

runonbeer

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Apr 15, 2002
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'00 Golf 02M, '10 Golf 02E, '02 UTE 02M
Faults? Is the IQ setting still where you left it after the repair?

check to make sure that the very small nut on top of the fuel cut off solenoid is fully secured (tight, but not too tight it is relatively delicate).

Try a fuel filter.
 

Burky

New member
Joined
Dec 27, 2016
Location
Columbus, Ga.
TDI
2003 VW Jetta
Faults? Is the IQ setting still where you left it after the repair?
check to make sure that the very small nut on top of the fuel cut off solenoid is fully secured (tight, but not too tight it is relatively delicate).
Try a fuel filter.
Unbelievable!!! The nut to the shut-off solenoid WAS loose. Tightened it up and the car has been running fine ever since!!! Thanks so much for your help "Run on Beer".
 
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