2002 jetti hard to start

I recently noticed my jetta is difficult to start when it is relatively warm outside. The glow plugs symbol only lights for a second. It is as if the engine floods. I have to turn it over for about a minute, before it starts, usually with the asssistance of battery booster. There is qiuite a bit of diesel smokes once it starts. This does not happen when it is cold out and the glow plugs work for about 15 seconds or so, any ideas?


Thanks

Pat

do you have a check engine light on? Are there air bubbles in the lines to the fuel filter?

I dont have the clear plastic fuel line section to see if air in line. My check engine light comes on for #1 glow plug, I checked that injector, says its ok. I cleared the code, but it keeps coming back. Probably the connecting line for that problem.

Yesterday, i put in new air filter and fuel filter. This morning it did same thing, took about 45 seconds to start. Glow plug indicator comes on for one sec and it still same problem. However, if it is cold out, glow plug stays on longer and car starts right away. ?????????

I disconnected my engine coolant sensor and the car starts right away as the glow plugs stay on longer. Does this help with any suggestions.

Did this syptom develope suddenly or gradually??
Injection timing that is retarded (not advanced near enough) will make for poor "cold" starts, as will low compression. Timing needs to be checked w/VCDS. Compression test needs GPs removed and a diesel compression tester.
If the IP or fuel lines (ofter the "T" fitting on the fuel filter) have an air leak it allows the fuel to run back to the tank when it sits for a while, but since it starts when the GPs operate, that shouldn't be a cause.
In temps aprox above 40F, it is correct for the GPs to noy really stay on or cycle for any length of time. The short time you see the indicator light is mostly a self test.
How does it fire up warm/hot??

Thanks jettawreck and yatzee

The poblem just developed. I have a compression for diesel, will try that. Since I have disconnected the coolant sensor, it starts right away. I gather this is because glow plugs are on longer. Clearly, it is not practical to have the colant sensor disconnected as I will not know engine temp and constant check engine light. I wonder if coolant sensor does not function at low end when temperature is warn out, that is, the glow plugs dont come on at all? The diesel runs well when operating. After the engine is warm, it starts well, even when i had coolant sensor connected. You may be right with injection timing? Any futher ideas? I will look to buy the VAG program.


Pat

Is the coolant temp sensor black? If it is change it out for the new green one.

I checked, it is a green one.


Thanks Pat

lafrenpr said:

Thanks jettawreck and yatzee

The poblem just developed. I have a compression for diesel, will try that. Since I have disconnected the coolant sensor, it starts right away. I gather this is because glow plugs are on longer. Clearly, it is not practical to have the colant sensor disconnected as I will not know engine temp and constant check engine light. I wonder if coolant sensor does not function at low end when temperature is warn out, that is, the glow plugs dont come on at all? The diesel runs well when operating. After the engine is warm, it starts well, even when i had coolant sensor connected. You may be right with injection timing? Any futher ideas? I will look to buy the VAG program.


Pat

Click to expand...

Coolant temp sensor may still be the culprit, but again, above 40-45*F the GPs don't really cycle on. The indicator light comes on every time for a self test very briefly, but that's not necessarily an indication of the GP activity.
Check for air leaks in the fuel system and the injection timing, although if this condition developed recently, I'ld want to know why it (timing) changed.

Thanks everybody for your help, problem kept getting worse , even with coolant temperature disconnected. I had a feeling it was fuel injector pump, brought it to garage, they stated they were unable to time fuel injector pump, so they changed timing belt. ??????? I did not think this would solve problem , and it did not. They then changed fuel injector pump and this solved the issue. They told me that they never encounter a problem like this before!!!!!!! well, it works fine now, but I paid for it. Thanks jettawreck and yatzee for advice. I guess i had bad luck, Pat, will keep u posted on any other issues