Just finished getting this 2001 Jetta TDI Auto roadworthy for a friend of mine. 525000km, but it runs great with the exception of a cold start problem.. hoping to get some opinions/advice on.
After the car is warm, even luke warm after sitting for 3-5 hours, it fires up within a half a second on the starter and runs great. When cold, after sitting all night it starts within a half second, but misfires and smokes white (extreme smoke). The car will stumble, misfire, and smoke white some days only 30 seconds. Other days it will sit there idling for 5 minutes doing this. Start driving it and the symptoms clear up right away.
Ambient temp is 15*C or warmer in the mornings right now
Compression is 375-390psi on all 4 cylinders. Tested after the sitting for 3-4 hours (still luke warm, i guess)
Coolant temp sensor is new
Fuel temp, coolant temp and ambient temp are nearly identical on the scan tool after sitting overnight
Glow plugs are new, although shouldn't be needed at this temp
No trouble codes stored
Timing is perfect, slightly advanced on the graph. T-belt is new. Installed professionally
Injectors were swapped with a known good set (from my own car)
Fuel filter is new
IQ is about 4.6 when warm
The car has great power and drive ability besides this problem. I have been running diesel purge through it (undiluted) to see if something in the pump may magically clear things up. To no avail yet.
I guess I have only the pump to condemn now. Anybody have any other ideas?
After the car is warm, even luke warm after sitting for 3-5 hours, it fires up within a half a second on the starter and runs great. When cold, after sitting all night it starts within a half second, but misfires and smokes white (extreme smoke). The car will stumble, misfire, and smoke white some days only 30 seconds. Other days it will sit there idling for 5 minutes doing this. Start driving it and the symptoms clear up right away.
Ambient temp is 15*C or warmer in the mornings right now
Compression is 375-390psi on all 4 cylinders. Tested after the sitting for 3-4 hours (still luke warm, i guess)
Coolant temp sensor is new
Fuel temp, coolant temp and ambient temp are nearly identical on the scan tool after sitting overnight
Glow plugs are new, although shouldn't be needed at this temp
No trouble codes stored
Timing is perfect, slightly advanced on the graph. T-belt is new. Installed professionally
Injectors were swapped with a known good set (from my own car)
Fuel filter is new
IQ is about 4.6 when warm
The car has great power and drive ability besides this problem. I have been running diesel purge through it (undiluted) to see if something in the pump may magically clear things up. To no avail yet.
I guess I have only the pump to condemn now. Anybody have any other ideas?