Car hard to start from cold

[mikk]

Hi All,

I have 2.0 slow Beetle which is hard to start when cold. It takes a few goes and sometimes 2 or 3 cylinders splutter into life at first instead of all 4. Once running it can be a bit sluggish for about the first minute (feels like flat spotting).

After this everything is fine and it runs like normal. If the car has been started in the past few hours it starts up without issue. As it cools down it becomes harder to start. e.g. 5hr of parking might need 2 short goes to start it instead of 3 long goes from dead cold. After being parked outside overnight it's hardest to start.

The car doesn't have many km on it (60000km) and the engine feels strong (stronger than another Beetle I have with more km). Compression checks out very well on all cylinders (slightly better than the other Beetle).

I thought it might be the MAF sensor but apparently not since I've swapped to a known good MAF sensor. The fault codes from VCDS are not really useful, it just comes up with "Cylinder (insert random number from 1-4) Misfire". There doesn't seem to be consistency between the cylinder misfire faults when I clear them.

Anyone have any ideas? Fortunately I have the luxury of being able to swap parts between another mechanically identical car, but before I go doing that, what should be my next course of action?

[Sirocco20348]

Do you have any oil in the car?
Fresh correct sparkplugs?

Starting basic...

[vdubmotorworx]

Coolant sensor....check if its a black or green body sensor....black ones are defo poor and seen some green ones fail too...if you have VCDS then check the coolant sensor reading when cold to make sure its similar to the ambient air temp when stood over night, or swop the sensor around from your other beetle...VDUB......

[mikk]

Thanks, will look at the coolant sensor.

To throw another spanner in the works, yesterday it started from cold in one go after being left out all night!

[mikk]

Changed the coolant sensor... still does the same thing. Any other things it could be?

[vdubmotorworx]

did you clear all your engine fault codes after fitting the new sensor? sometimes a fault code can stop a new component working if its not erased...VDUB..