Cold start FI problem

[hitman208]

Now it's getting colder I really should get around to sorting the cold start out on my 411 fitted with a 1700 and 'd' jet injection.
The problem seems related to air temp and a cold engine. When its cold it will start but is very smokey, not blue oil smoke but darker, like its over rich. It also runs like a bag of nails.
I have cleaned and made sure all connections in the engine are tight and this made no difference. All air pipes appear in good order and tight as well.
Once the engine has warmed up it runs very well and all the time the engine is warm will restart with no issues.
This leads me to suspect a temp sensor which I assume is fitted somewhere? Any ideas?

Thanks in advance for any help or ideas
_________________
'70VW 411LE 2 Door Saloon

[raygreenwood]

How cold is it outside?

Three things to check:

1. On the left hand cylinder head you will find a single 13mm bolt with a wire going to it. This is the TS-2 which is the cylinder head temperature sensor. Test it's resistance cold and then after about 5 minutes of running and then when fully warmed up.

Post what you have and we can consult the book as well.

2. Screwed into the left side of the center I take manifold is a two wire sensor. Tbiw is the TS-1, your intake air temp seanor. Again, test resistance cold, then after t min and when engine is fully warmed up.

NOTE: a quick test that sometimes helps especially when it's not yet actually "cold" outside but just cool...like 40-50°F...like in spring or early fall.....is to unplug the TS-2 sensor and see if that cleans things up. This is very common that this helps just during a couple months of the year. There are reasons for this we can get into later.

3. Next time you start cold.....at your current outside temperature....unplug the two wife plug from the cold start injector on the rear end of your intake manifold. If it starts cleaner....and your outside temperature is actually not yet cold enough to require the cold start valve to operate, it may very well have a bad thermotime switch. We can test that later.

Ray