MFI injector nozzle issue
 

In the past, I have noticed that when starting, the raw fuel from my cold start valve only gets sucked into # 3 and # 2 stack .(My cold start valve & thermal time switch work properly.)
At times on warm starts after sitting for 2/3 hrs I get a puff of black smoke and these 2 plugs show more soot than the others. If I unplug the system it eliminates the smoke and the car starts fine when warm, but overnight garage temp around 60deg the car cranks much longer. I live in SW Fla. and that's about as cold as it gets.
My lines and nozzles are all clear and I even checked the and the little brass pee holes are in the nozzles.

Its real easy to connect a switch to the cold start valve to dissengage it. My thermal time switch was acting funny and they are a couple hundred dollars to relplace so I mounted a switch on the rear access tunnel where I turn off the cold start valve when the car is warm and not needed. Works perfectly under all conditions.

Chris
73 911 E

Chris,
That sounds like a good idea. Sometimes, after I have unplugged the system, I find that the car still needs a squirt of fuel when warm as it cranks a little longer. When connected it does start up much quicker, but then, at times, I get a little puff of black smoke.