Hard starting after sitting for 8+ hours

[Matdman]

2000 Jetta ALH is having some starting issues. After I get out of school at the end of the day, I hop in and all it seems to do for the first 30 secs is just crank and crank with no sputters. Exhaust comes out of the tailpipe while it is cranking. After a while it starts to sputter and with some persuasion it will finally roar to life. It has been in the -15c range this week, but it has had zero problems starting in -30c not even plugged in. I still need to check IP timing with VCDS, but does anyone have any other ideas what my problem might be?

 

[manual_tranny]

Check your fuel return lines, if they are a little soggy they are leaking diesel and can contribute to air ingress. That is one common source for hard starting that sputters and starts after some cranking, but only when the car sits for a little while. Look for leaks or improper seals on fuel supply lines too but they are an unlikely culprit (assuming that no work has recently been performed on fuel filter or fuel injectors)

Finally, you should look for diesel leaking out of your injection pump case where a gasket seals the case.. but likely/hopefully it will be amore simple problem than that.

 

[Matdman]

No leaks on any of my fuel lines. Just had an issue after a trip around christmas when my fuel filter tee o rings were letting air in my filter. So everything fuel line wise is pristine. I forgot to mention that when my car is plugged in (frostheater) that it fires up immediately with no issues.

 

[LNXGUY]

Battery/starter?

 

[Matdman]

Battery is 1 year old and correct size, and starter is 10 months old, Bosch reman.

 

[LNXGUY]

Even though you replaced the thermostatic T, it could still be the issue. What I'd do is pinch the feed/return lines after you're done for the night and see if you have the same issue starting in the morning.

 

[Matdman]

Figured it out. Car is throwing a P0380 code for my glow plug circuit. Just changed them before this winter, so I don't know why it isn't working now. Thanks for the suggestions guys!

 

[manual_tranny]

Did you replace the harness too, or just the plugs? The harnesses are known to be fickle.

My car threw that code for 3 years, I kept glow plugs and harness in the car just in case... but the car always started down to 0 deg F so I ended up never replacing the parts.

 

[JB05]

Some DeOxit on the harness may help.

 

[Matdman]

Yeah the harness and plugs were replaced. Thanks!