engine studders

[champman]

Hi, I've got a 2004 golf tdi, with BEW engine, and 240k miles. I've been having a problem whit the engine studdering/rough running after it warms up for the first time each day. But if I let it sit for 15 min. it will run fine for rest of the day. and I was not getting any fault codes. Well last week I had the problem again and I shut the engine off and back on while I was rolling and got the fault code P0201. I took it to the dealer and thy said that the #1 injector was bad and it would cost $2000 mostly due to having to pull the timming belt. Well I don't believe that you need to do that and brought the car home the next day. On the way home same problem. Runs rough afte 3 miles sit for 15 min. and it runs fine.

Today I reset fault code, took it for a drive and same thing with no faults.

Anyone have any ideas?

[Turbo Lag]

If it use the same injector as the B5 from what i read is the Piezo valve wiring is what normally fails.
The piezo socket on the injector has TWO pins.
Neither should be connected to the casing (Earth or “-“).
Set your multimeter to continuity or Ohms.
Place one probe on one connector pin and the other probe on the injector body.
The meter should read “1” and not buzz.
Repeat for the other connector pin. If the Piezo valve has failed the meter will buzz or give a reading. A failed injector will give a reading of 400 – 500 Ohms or less.

Or you could run some diesel purge thru it.

[champman]

Well, I've learned a lot about this engine and it's parts in the last few weeks.
I've found that no you don't need to remove the timming belt to change the injectors.
Also it's easy to check the injectors. Which I did and found that none of the terminals were shorted to ground. Also the harness rail wiring was also good.
Also I had to remove the EGR valve to remove the cyl head cover to get to the injectors, and found the valve so coked with soot that I couldn't even see the probe that sticks out into the intake flow.

I cleaned the valve and reinstalled everything and now after 250 miles it runs great!
After 240K miles this is the first thing I've had to do except get that dog collar plate to keep the intake hose installed.

After reading about the injector piezo valve I can see why a lot of people told me they never go bad, nock on wood. And I have also learned a lot about the EGr valve, after learning it's function I can see it causing the problem that I had. I think the fault for the injector was induced by me when I switched the engine off and on while I was rolling.

Time will tell but I believe it was a good fix and saved myself $1900.
Thanks for the help