cold start problem not resolved
 

1987 Carrera
With the engine totally cold, started the car. The engine starts right away but in a missing fashion for about 2 seconds and then goes to 1200 RPM...And does its routine going down to 900 as programmed. The funny thing is that if I start it again 5 or 6 hours later, it starts properly, no hesitation
I did remove the valve cover on the upper left side, there were a few smears of oil but the roker shafts seem to be at in their place, changed the gasket and secured the plugs wires with RSR hold downs.
Just installed a new fuel pump so it is not the check valve
Any thoughts??

Following

David you post is like guessing game.Not solved..what did you do to try to solve it , that would help to mention here,how about that?.... so people can actually follow....
Ivan

problem with cold start
 

I did what was described and awaiting new wormer spark plugs non resistive to replace the current ones.
Other then that, I do not have any ideas of what to do next to resolve the cold start "missing" symptom...
It is not a big deal because it only lasts for 2-3 seconds...but it annoys me.

My cars did exactly what you described until the Idle Control Valve completely failed. Once replaced - problem solved. My guess is that your ICV is failing.

Does the Idle Control Valve control the bypass air, only when the engine is cold, or also when it is warm ?

From one PeterM to another Peter M!

ICV controls bypass air at all temperatures.

Many thanks Peter M - great name you have !

I will use that information in my own tread on idle issues

Please test things instead of replacing them. A fuel pressure meter hooked to the fuel rail would have saved the cost of a fuel pump.

Things to check at this point.
- ICV
- Idle position switch
- Cylinder head temp sensor

And doing the idle speed setting procedure would be good about now.

Reference and speed sensors could be starting to fail or covered with oil/dirt.

CHT sensor is a good one. I had changed mine a few years ago when it failed as well, so that's why I didn't bring it up.

It's not a hard fix - just a little tricky getting the socket on the sensor.

Subscribed. Same symptoms except mine chokes and coughs for about 15 seconds before it revs up and down. Then like yours its fine. Even after sitting for hours.

I took it in for this. They did a smoke test on the vacuum line and replaced several hoses. Didn’t fix it....

Oh, forgot to mention that I get a nice bit of white smoke now that accompanies the choking. This is new too.