Hard Start need help

iheartbacon

Member
Joined
Feb 20, 2011
Location
Appleton
TDI
2001 Jetta
01 TDI 5 Speed
Weather has recently dipped below freezing and Jetta has become hard to start. Then the other day I got a CEL for glow plugs. I changed those out with some new bosch ones and light went off but still starts very hard and lots of smoke and seems to stumble. When I turn the key the glow plug light comes on but goes out almost instantly. I replaced the temp sensor this summer so I doubt that is the cause. Last winter when cold it would stay on for at least a few seconds. Any idea where to go from here. Thanks
 

chromeBuddha

Veteran Member
Joined
Jun 30, 2006
Location
Arlington, TX - DFW metroplex
TDI
2002 Golf TDI manual
Just to get an idea if extending the GP glow time will help, you can disconnect the temperature sensor. This should maximize the GP on length. If it is still starting hard, you should check your timing. Make sure it is advanced toward the top of the graph. If you have vag-com and are able to do that, you can also check your IQ.
 

iheartbacon

Member
Joined
Feb 20, 2011
Location
Appleton
TDI
2001 Jetta
I disconnected temp sensor and glow plug light stayed on for 10 seconds or so and car fired right up. I put a new sensor in from the dealer and still having same problem as before.
 

Dodoma

Veteran Member
Joined
Mar 30, 2004
TDI
2002 Jetta White
After replacing the sensor your problem remains that means the senor was not the problem. You need to extend the glow plug time by someway. See if Leonard Harview, a TDI veteran, can suggets a solution.
 

iheartbacon

Member
Joined
Feb 20, 2011
Location
Appleton
TDI
2001 Jetta
Thanks for all help. I have a vag com. What sensors do I need to check with it? Battery is a few years old, but I didn't think that would effect how long the glow plug light stays on.
 

DanG144

Top Post Dawg
Joined
Aug 2, 2007
Location
Chapin, South Carolina, USA
TDI
2005 A4 Jetta 5spd
What does your timing look like?
Idling, engine warm, SELECT, Engine module, BASIC SETTINGS, group 000, then GO, (now note the reading in the second field), then timing graph, then find your proper graph from the pull down menu. You can read your timing numbers and check against the graph. I suggest near the top line of the three.

Tomorrow morning, before starting it, take the key to ON, Select, Engine, measured values, measuring block 007, and note the readings on the 3 temperature sensors. They should be within 2 or 3 C of each other.
 

gootie

Veteran Member
Joined
Jul 3, 2005
Location
Madison,WI
TDI
Golf,05,white TIP
Hard start need help

If the battery is too low in output you will turn over but not fast enough to generate compression heat. Check your voltage in cold environment before starting. My last experience had battery at zero F reading 11.8v and would turn over engine. It took 2-3 attempts to get it running. All glowplugs were fine. A fresh battery(VW) solved hard start for me
 
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