Cold Start Valve repair

[col320ce]

I thought I'd share my repair of the injector nozzle of the CSV.  Basically one of the nozzles was missing and it was dribbling fuel.  The photos are pretty self-explanatory but:
I found a brass screw with an unthreaded portion that was the correct diameter (~4.6mm).
Drilled a 0.85mm hole down the centre.
Cut it to about 4.5mm long. 
Put it in the chuck of a drill and used sandpaper to make it slightly conical (1000 grit)
Cut a slot in the back of it to help fuel flow
Pressed it in using a wood vice
Cleaned the spring and valve and bench-tested the solenoid with a 12V battery
Last photo shows the position I was testing it in. The air connection at the back is disconnected. (it's actually a photo of the other car)
Turned the ignition on without starting the car to check that there were no leaks or dribbles.
Started the car in the test position to check the nozzle spray etc.
The jet is not quite as strong as the original but the car starts perfectly now.  I think if the groove in the back was deeper or a section was cut out it would have improved the fuel flow.

[col320ce]

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[col320ce]

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[ja17]

Very resourceful Col !

[yves]

Nice job…! Drilling so small 🥶

[stickandrudderman]

I like it!
Only slight concern is to be confident enough in the interference fit to ensure that the new jet doesn't fall out and get ingested.

[mdsalemi]

I thought I'd share my repair of the injector nozzle of the CSV.  Basically one of the nozzles was missing and it was dribbling fuel.  The photos are pretty self-explanatory but:
I found a brass screw with an unthreaded portion that was the correct diameter (~4.6mm).
Drilled a 0.85mm hole down the centre.
Cut it to about 4.5mm long. 
Put it in the chuck of a drill and used sandpaper to make it slightly conical (1000 grit)
Cut a slot in the back of it to help fuel flow
Pressed it in using a wood vice
Cleaned the spring and valve and bench-tested the solenoid with a 12V battery
Last photo shows the position I was testing it in. The air connection at the back is disconnected. (it's actually a photo of the other car)
Turned the ignition on without starting the car to check that there were no leaks or dribbles.
Started the car in the test position to check the nozzle spray etc.
The jet is not quite as strong as the original but the car starts perfectly now.  I think if the groove in the back was deeper or a section was cut out it would have improved the fuel flow.

Nice work! This would be a great writeup for one of our publications (Pagoda World or Pagoda Notes) and also for inclusion in the tech manual.

[col320ce]

Thanks!
It's a tight fit. I don't have any real concerns with it falling out.

[Lori]

The needle is available
https://www.niemoeller.de/en/w113/w113/B042/140/d08800a-valve-needle-in-cold-start-valve

[wwheeler]

Nice work Col! If you ever have a metal to metal press fit that you don't want to come out, use a bearing retainer fluid. https://www.amazon.com/Loctite-555338-Temperature-Bearing-36-milliliter/dp/B00070LQWE

There are a lot of different compounds. 

[col320ce]

I didn't think to add Loctite. Great suggestion.

I actually used the replacement needle from niemoller however it leaked but didn't after cleaning and reusing the original.

[col320ce]

Another thing I was thinking of changing if I had to repeat the exercise would be to make the drilled hole slightly conical (wider at the back) as I think this would increase the velocity of the fuel flow through the nozzle.

[Kevkeller]

I wonder where the original went?