Correct Cold Start Valve...?

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You're welcome Joe. I don't know what the difference between a 400 and 401 would be. Just for reference, here the picture of my 400 valve:
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Maybe OT but I can assure that I removed the cold start valve at all with no difference I can feel in real world, except cold idling is maybe less smelly and smokey now (ambient is 5-10°C). I am sure many here can confirm they run without a cold start valve.
Not a reply to the OP, I realize, but a cost-effective solution for sure when you don't exactly know which cold start valve to use.

 

To my understanding, the additional injection of fuel via the cold start valve happens for a few seconds only with a coolant temperature below 35°C, controlled via the thermo-time switch.

 

I don't know the exact details of the cold starting strategy, and in particular what triggers the valve, and what switches it off, but my exhaust was to me a bit too much smelling and smoking during cold idling (for much longer than a few seconds); my reasoning was that a leaking cold start valve could be the cause of it, so I wanted to try without, to realize that it made no difference to idling if not a bit better for smell/smoke. I would assume maybe in extreme cold weather the cold start valve could be needed, otherwise it wouldn't be there, but I can positively say that on my car at my place, despite a cold winter in relative terms, I can well do without it.
So if I was about purchasing a new one, like the OP is, I would try without, first...
As for myself, as I am maniac of retaining an original look, I left everything in place, just I used a blank bolt and teflon thread sealer for the banjo fitting, instead of the hollow bolt; it saves the looks and it also saves dangerous attempts of plugging the fuel lines in "creative" ways... the level of fuel leaking risk is stock (a couple of copper washers, better to be replaced). By the way the valve connector is still plugged, so the valve won't probably stick forever if I will ever want to revert back to stock (which I am not at the moment).
I hope it helps the OP...

 

Easy enough to just remove the cold start injector from the manifold and either: 1) block the opening in the intake plenum to see if fuel is leaking/coming out of the cold start injector during engine idling, or 2) manually run the fuel pump (without running the engine) to see if fuel is leaking out of the cold start injector. It's also possible that an electrical problem is wrongly actuating the cold start valve when it shouldn't be -- did you ever try just unplugging the cold start injector to see if you got the same effect?

 

Hi no I am sorry I didn't...

 

If it is really leaking, you have almost no choice but to do as you have done, or replace it. You could also measure the voltage between the two pins in the unplugged harness connector of the cold start injector during cold idle: if (correctly) 0 VDC = not an electrical issue; but if +12V DC = an electrical problem.

However, I would say that, if your cold starts are good at 5 deg C with no cold start injector, you probably have a very rich mixture situation (either just being set rich, or the WUR cold control pressure is abnormally low and adding even more richness than usual). On the catless euro version cars, this isn't much of an issue as IC engines run great when rich and no cat to overheat. On a cat-equipped US version, your coachwork is on fire .

 

Hi Steve,
yes definitely I have a rich mixture, as the exhaust sure smells gas, both in cold and warm (and hot) engine conditions, although a bit less at cold than with the CSV in my very subjective personal perception.
Honestly I have no reference to say wether the level of smell is normal or not for a non cat vehicle, as I don't have any back-to-back comparison available; it is rich to me, but as a matter of fact the engine runs like a charm, so I am reluctant to fix something that is not broken...