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Discussion Starter #1
I've got an '02 Jetta tdi that just had it's 160k timing belt change and it was done by the same private shop that did the first one. After she drove it home the wife said it sounded like the air was leaking out of the tires, which of course was a connection that wasn't tightened and was leaking boost. We returned it and they fixed the leak, i don't know where the leak was. It ran a little "off" but nothing drastic after this mainly a little jumpy on start up. The fuel temp sensor code was read and we planned to change that later. A couple of weeks go by and it starts to stumble when the throttle is chopped like at a stop light. It progresses to stalling sometimes and the idle will hunt a little on slow shifts(manual tranny). The car seems to run fine on the highway at constant speed. We took it to another shop mainly out of convenience and he's diagnosing it as a bad injector pump. I'm not a diesel expert but that didn't sound right and i wanted to get some opinions before dropping that much coin.
Also does the area where the fuel temp thermistor sits normally run dry or is it wet with diesel? He's saying there is corrosion in there.
 

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I had a corrosion problem with fuel temp sensor, it turned out that a wire on the harness had rubbed through and was shorting it out, burning the sensor. Follow the wires from the fuel injection pump and check for shorts. See here for pics: http://www.myturbodiesel.com/1000q_how_to/multi/fueltempsensor.htm

The sensor is normally totally wet but water in the fuel could corrode it.

Did the shop use the timing belt locks? Most cars use index marks to line up the timing belt, the TDI has none. This often causes problems for garages because they don't want to buy the tools. You must use the timing belt locks because the sprockets rotate when the belt tensioner is tightened. If not, the sprockets can be slightly off, the cam timing is off, the injection pump timing is off, etc. This could cause poor running.

The most recent parts are rated for 100,000 miles. There is no reason not to use these parts because you should replace all rollers/tensioner while you're in there. I have no financial interest in selling parts, only an interest in seeing people not screwed up.

Normally I'd say that if they did the first timing belt and it lasted this long it'd be fine but these guys left a hose loose and now the car isn't running right. Read this timing belt how to
http://www.myturbodiesel.com/1000q_how_to/a4/timing_belt_part_1.htm
http://www.myturbodiesel.com/1000q_how_to/a4/timing_belt_part_2.htm

for an idea of what should have been done. Almost stalling and hunting idle will not be caused by a faulty fuel temp sensor. My guess is that the injection timing is off (it could be caused by the injection pump sprocket being off) or that the injection quantity is off. See this: http://www.myturbodiesel.com/1000q_how_to/multi/IQadjusthammermod.htm on how to check it.

You need a VCDS cable to see the sensors.
 

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Discussion Starter #3
Thanks for the reply, i read the threads and have a good understanding of the procedure now. The idea behind the tdi was so i wouldn't have to work on it but it looks like you always get dragged in.
It looks like we're in agreement that it's probably not a failing pump just the IP timing. I know what questions to ask now so i can gauge their level competency. My guess is that they got lucky the first time.
I need to get the car back which is a drive of about 40 miles, as a wild guess would you expect any mechanical damage? I realize this is a loaded question with many variables that we don't know.
 

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Probably no. It takes a bit of movement for the valves to hit the pistons and if it's running that isn't the case. However, if the belt slips or loses tension, it will fail and cause damage.

If I were you, (assuming that you throughly understand the procedure and are competent to work on your car) I'd retime it yourself. You don't need to remove the belt or motor mount. You just need to do loosen the camshaft and injection pump sprockets and do the final steps. This assumes that they did replace all the rollers, etc. I wouldn't expect the original rollers to last much longer if they were never replaced.

PS, some shops use paint marks to index the timing belt to the sprockets but this is useless. The TDI sprockets should rotate and unlike many cars, the timing belt has no index mark on it. Sometimes it works, sometimes it gets screwed up and causes major engine damage. Even if they put the new belt on exactly how the old one came off, it's not right because the old belt stretched a little, tension isn't set right, etc.
 

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Paint marks = impending doom! Many shops have applied what works on other cars to TDI and it either breaks driving away from the shop or 5-10,000 miles later! It's really given VWs a bad rep.
 

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Discussion Starter #6
I would need to buy the VCDS to do this ? I'm not against this and would like to take a look under the cover.
I have pretty extensive V8 gas experience and spent time with a Benz 603 diesel motor in my past so the procedure doesn't bother me. I just don't wanna!
Thanks for the help.
 

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Discussion Starter #8
The bill for the car shows code "P1562 fuel quantity adjuster" being read before and after he changed other parts so that looks like a good place to start. I'll look at the links for the VCDS that are in Chittys first post where he pointed out the possibility of the adjuster being wrong. I didn't realize how advanced this little motor was before this forced march.
 

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Discussion Starter #10
I haven't really had time to get into it yet. The glow plug light flashes all the time now if that tells you anything else.
 

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The reality of me not having the time to tackle it made me find a small local shop that had the Ross tech software. The mechanic didn't have extensive experience with this motor but was willing to go thru and do it right, i have good confidence in his abilities. The pump timing was pretty far off so he corrected that and tried the motor again. It didn't clear it up and he's still getting the qty Adj. error and the glow plug light flashes continuously. He commented that there was a large amount of corrosion on the top of the pump where the temp sensor is.
He's thinking the most likely thing is that the corrosion got down into the pump and damaged the pump pistons.
I don't know what the failure mode of a diesel injection pump is like. Can they work poorly or do they completely quit working? The only problem is a stalling when returning to idle or stumble when shifting gears.
Unless you guys have another idea i might have to throw a pump at it which would hurt.
thanks
 

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If it really is the quantity adjuster than the pump is bad. You could try manually adjusting it and seeing if it does something although it should not: http://www.myturbodiesel.com/1000q_how_to/multi/IQadjusthammermod.htm

When a pump fails it can both work poorly or completely quit. It sounds like you do have a bad pump because the inside of the pump should be completely pristine. There should be no corrosion whatsoever, only maybe some yellowing from age. There should be no dirt or water specks anywhere. It sounds like the pump really is bad.
 

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Rebuilt through an authorized Bosch service center is a lot cheaper and is just as good.

http://www.boschservice.com/ServiceLocations/DieselServiceCenter/Diesel+Service+Center.htm

see the above link for service centers, not all specialize in VW pumps. These guys below have done a lot of TDI pumps - give them a call and talk to them for pricing.
DFIS - Diesel Fuel Injection Service
8922 NE Vancouver Way
Portland, OR 97211
(503) 235-1947‎
[SIZE=-1](503) 285-1213‎

kermatdi and boraparts also sell injection pumps. http://tdiparts.com/catalog/product_info.php?products_id=881 http://www.kermatdi.com/servlet/-strse-30/ALH-Injection-Pump-10mm/Detail?category=-Maintenance+Items


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Discussion Starter #16
The numbers i'm getting from a couple of places for Bosch rebuilts are $850 to 900 ish plus core charge. If they work on your pump it could go down to $650 depending on what's needed.
I talked with a local shop about it and he said the tool setup to do those pumps was $35k and then they wanted you to push already rebuilt units for 4 years. They passed on it.
 

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I'm living the P1562 CEL as well. I'm seeing air in the clear fuel line when I wiggle the rubber line going to the fuel filter, not the one connecting to the "T" the other one. I replaced the filter and the "T" thinking maybe it was a defect, still bubbles. Yesterday, I replaced the dual black rubber lines going to the filter with some from a salvage yard, still getting bubbles. I do not want to rebuild I.P. unless it's necessary. 02 jetta 5M 194,xxx mi.
 

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Discussion Starter #18
To wrap this one up it seems like it was the pump. It runs good now and you can feel it come on the pipe which hasn't happened since the first belt change. The best guess is that some of the corrosion that was on the top of the pump worked it's way down to something important.
Now the exhaust broke behind the resonator near the trans crossmember, more fun.
thanks for the help guys.
 
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