308 GTB QV UK spec cold start system

Had a chat with the workshop who say they disconnect the cold start (extra injector in to the plenum) as it tends to flood on a cold start. Mine starts easily cold; not quite so easy when hot (but I’m still learning the idiosyncrasies). HC at the emissions test was high 1179 (max allowed is 1200). Whereas in 2022 (1000 miles ago) it was 64! I suspect the idle mixture was adjusted to compensate. When running normally it is a bit hesitant at 1500 rpm but smooths out when it starts to work. Anyone heard of the issue with the cold start system. As has been said it didn’t come from the factory like that though fuel has changed a bit since then!

 

I think you're talking about a few different (but related) components here.

The cold start injector only runs for a brief period when starting the car (few seconds?). I could see how it could "flood" (using that term loosely) if you fail to start the car, and have to try many times (each time the injector would run). Once the car started though, you'd burn through that extra fuel pretty quick (some extra smoke out the exhaust). So you'd need many failed attempts to really flood the engine with fuel. A leaking cold start injector is a different story though, as that would continually add fuel beyond what the fuel distributor expects.

There are other components that address "cold running" (as opposed to "cold start"); which add more fuel and more air until the car is warm. For example, the AAV (air) and WUR (fuel). Then of course, you have the idle screw; which also lets more air into the throttle body.

 

With the ignition on I checked for 12v at the (disconnected) plug that would power the solenoid and valve. Nothing so either it has failed or been disconnected. I’m not sure of it’s location so I can’t see if it’s disconnected. Certainly a leaking injector would cause issues. The thermo switch is available but pricey: the injector seems unavailable Though as it’s Bosch I wondered if it can be rebuilt. I need to better understand how it all works before throwing new parts at it. I have access to a emissions analyser (as used for UK MOT) that should give clues.

 

Is the car MOT exempt anyhow .
For those unfamiliar with U.K. vehicle testing you can once a car is aged 40 or over apply for a test exemption.
For the California guys imagine that ……never having to test it .

 

Why do you assume there's something wrong ?

(Apologies in advance if you are one of those owners like some others here who prefer to rebuild their cars rather than drive them)

 

Not till 2025!

 

It’s not necessarily wrong but disconnecting something the factory fitted begs the question