Working choke in a 308?

The only time I use my choke is for an anti-theft setting when not home. Sounds to me that your cold idle setting needs to be bumped up.

 

You should be able to search for past posts on this topic. I have a '76 Euro spec GTB that I've had for 12 years now. Upon taking delivery of the car I had it serviced by a very reputable Ferrari mechanic here in CT. One of his first bits of advice to me was to never use the choke. His reasoning, gained from his many years of experience, was that there is a tendency for the choke cable/linkage to bind, even when the choke lever is in the full off (hot) position, resulting in the choke being partially engaged at all times. This adversely affects the engine performance. My choke cable has been detached/choke disengaged/linkages removed for essentially the entire duration of my ownership. My starting procedure is similar to yours. I let the fuel pump run 20-30 seconds to prime the carbs, then FULLY depress the accelerator 3-4 times, turn the ignition and when the engine catches, then feather the throttle to bring it to a fast idle of say 1500 rpm, holding that for a couple of minutes or so until the engine then idles on its own. A bit of a hassle, true, but I've gotten used to it and the procedure hasn't failed me.

 

Without the choke, you need to use the carb accelerator pumps to "squirt" enrichment at cold start-up to keep it running as Anthony indicated. Not all carbs are designed the same. The choke spools inside the Weber DCNF can stick in the open position (regardless of where the choke lever is set inside the cabin). On a '78-'79 US, with cats, a stuck open choke spool can overheat the cat(s) and start a coachwork fire (this is how that "rule" got started). If you are now catless, a stuck open choke spool will just foul a spark plug (and cause a cylinder miss) so far less risk of disaster (but still creates a problem that needs to be fixed).

 

Excellent explanation. A nagging question on my '78 and now I know. Thanks.

 

I’ve just collected my 308 GTB QV and noticed the cold start wiring has been disconnected I’ve asked the workshop to explain. Having said that it started just fine and we’re having a “cold snap” in the uk.
Of course no choke as such as it’s injected.

 

If you mean that the cold start injector has been unplugged, this can be a (poor) band-aid fix for a failed Thermo-Time Switch system (which is wrongly always opening the cold start injector instead of just during the first couple/few seconds of the initial cold start), or a WUR that is not operating as it should (control pressure too low when cold).

 

I do the same - run fuel pump for 30 seconds then FULLY depress accelerator 4 times - turn ignition and it catches easily (1980 carbed 308GTB)

 

or a WUR that is not operating as it should (control pressure too low when cold).[/QUOTE]

WUR??

Thanks. I await a reply from the workshop!!

 

WUR = Warm-Up Regulator (sometimes also called the Control Pressure Regulator in some CIS documentation IIRC).

I should've added that your idle mixture could just be set very, very rich (which ICE tolerate well, and since you probably have a euro, no cat(s), you won't catch on fire like a stock US QV does when set too rich ). If it is set very rich it can probably cold start OK with the cold start injector system disabled, and, if the cold start injector system was working, it could push it into being "way too rich". I can say with some certainty that no 308QV was delivered new with the cold start injector unplugged.

 

So is it only at idle it’s way too rich or throughout the Rev range? Either way I suspect it would fail the emissions part of the annual “MOT” test which it has just passed….(I was a tester years ago). Presumably once warm it can be adjusted leaner to pass before returning to richer for delivery to me! I prefer things to work as designed but I need to find out what to adjust as the “fix” Also what is required to do the job properly before I “discuss” it with the workshop. The car has a 3 month warranty and I paid the asking price on the understanding the car was “right “. I do however accept its 38 years old. A bit….

Thanks for your help. I’m a very new owner- now had you needed advice on MGBs I’m your man!!

 

I've had a look at the wiring diagram-seems straightforward: Ignition- fuse-relay-thermo switch-solenoid valve. So diagnostic would be: Ignition on (cold engine): should be power to the thermoswitch and from there to the solenoid valve. If nothing then either the fuse or switch (possibly the relay) have failed. If power to the solenoid valve then the valve may be suspect. Do they click if the solenoid is operated? With the engine up to temperature, there should be no power to the solenoid valve.

Does this make sense?!

To my mind, if set way too rich to benefit cold starting, then hot starting becomes far more difficult.

 

Mostly at idle/starting, but I only suggested that as one possibility for why the cold start injector would be unplugged to aid starting. (Your MOT test may have very generous test limits, and a Shop can have a special "relationship" with the Tester .)

You can download a copy of the Mondial8/QV 281/83 WSM here:

https://www.dropbox.com/s/z99soo68ny9n2qa/Mondial8qv_workshop_281-83.pdf?dl=0

Chapter D covers the operation, checks, and adjustments of the Bosch K-Jet without Lambda CIS system (also used on euro 308QV).

 

Thanks! I just bought a reprint workshop manual (for £130!) and it's very sparse: section D is missing. All I got was sections ABCEM!

 

Now you know why some on here hunted down a carb car ( Webbers ) , you will miss the simplicity of SU s in a total analog car , the MGB .
This Sprites on SU s as well .
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Welcome to the F car fold btw .

 

Typical Ferrari to be missing sections - I suspect the book you bought was the 1989 manual including the 328

 

In truth the B is supercharged so the twin SUs have given way to a blower with a single carb but I’ve played with many a twin carb-(most carb problems are ignition! )
Love the Sprite-Iris blue?