QuestionMy 2002 Jetta TDI ususally starts on the first try. After driving from 5 to 65 minutes and stopping, it won't fire up on the first try. In my five minute example, short trip at city speeds, stop at post office, car won't start without multiple trys in warm weather. In 65 mins, the car was operating at highway speeds 65-70 mph.
The starter cranks all the time the key is turned to "start." The engine only fires initially when it fails to start, as if fuel is not getting to engine.
Do I have a fuel line clog?
AnswerHi John,
If it is starting on the first try, I would eliminate the glow plugs and fuel clog for now at least.
1) I'd suggest a thorough tune-up (if you have not already had it done). Document it, and you know that's ok. Include the fuel filter.
2) Make sure there is no water in the diesel fuel, put some conditioner in there.
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1) The first culprit could be the "glowplug sensor". One of it's purposes is to basically regulate the heat/need for the glowplugs while engine is at certain temperatures. The period of 5-65 minutes is a warm-to-hot start problem. The glowplug sensor is one thing to check (use a good book, to show the testing procedure. You just need a Volt/Ohm meter).
2) The next culprit could be a bit costly...it is called tha Mass Air Flow Sensor. It is the thing that has a big rubber boot on it, leading to the air filter. Check all those hoses/boots/ for any cracks (especially the spaces between the accordian-looking hose), and tighten any loose hose connections. If all that fails, see if you can find a manual that shows how to troubleshoot before replacing. I believe there is a temperature sensor in the MAFS, which is not replaceable by itself, you need to get the whole MAFS.
3) If equipped (sorry, going on memory now), your Jetta TDI should have a MAP sensor as well. (manifold absolute pressure sensor). It's another sensor that gives the brain heat/temperature information as it relates to starting.
4) Finally, if all else fails you are going to have to check your injection pump. It's a relatively easy test, and depends on your specific type of vehicle Sedan/Wagon. Again, using a good shop manual, look up the section on this, and make sure the pressure specs on the pump are exactly on the mark. If pressure is even a little out of range, it can cause all sorts of problems. In my opinion, this is a wonderful engine, but is prone to some quirks.
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If this sequence doesn't fix the problem for under $200, let me know. I'd like to see this through, and learn as elimate the most obvious. Fixing a car in your mind is much more difficult than having your head under the hood! I'm sure you'll be running in no time.
Keep me posted, and Best of Luck.
FYI:
The 2002 Jetta Sedan TDI was assembled in Mexico
The 2002 Jetta Wagon TDI was assembled in Germany
---- Hemmings Motor News
You should be getting between 41-49 MPG, and experiencing no surges while cruising once all this has been checked.
Go for it! Ron
