AAV - Electric replacement kit

Hi Volker,

The cold start valve on the 1973 Volvo P1800 stuck open, creating a vacuum leak once the engine was warm.  I installed an electric cold start valve kit indicated for the D-Jetronic but clearly using K-Jetronic components.  The valve's electric lead connects to a tap on the fuel pump relay and the cold start valve itself is mounted near the cylinder head on the intake manifold.

The engine starts well, even at -5°C, but unlike the original valve, idle speed is low--about 600 RPM--until the engine starts to warm up.  The cold start function is serviceable but does not exhibit the faster cold idle typical with the original cold start valve.  Even the low idle is smooth.

Is this kit considered a viable replacement for the wax-filled original valve that mounted on the cylinder head directly?

I would appreciate your comments and recommendations.

Best regards,

Glenn
 

Hi Glenn,

before I can comment I will need what components you actually installed as a replacement.

Hi Volker,

Here is a link to the description of the cold start valve that was installed:
classicvolvorestoration.com/product/conv...-idle-control-valve/

The next step is to start the engine with the power to the valve disconnected. I haven't tried this yet.

Thank you and best regards,

Glenn

Hi Glenn,
the conversion kit is new to us... but we know the components that are used and understand the function by having a look at the photo.
The main difference and disadvantage is the electrical valve changes the airstream not by engine <coolant> temperature, but by time,
But maybe this isn't much important.
Regarding your problem: Check if not / how much air goes through the unit in cold / warm state. The valve should be open in cold state and totally closed when warm.
Maybe you have an incorrect wiring and the unit gets heated up without the fuel pump running?
Try to start the engine with the <cold!!!> valve electrically disconnected (remove the fuse). The engine should start with higher revs the and slow down when connecting the power.

Best regards
Norbert

Hi Glenn,

are we talking cold start valve or Auxiliary Air Valve (AAV)?

If we talk of AAV, then just find someone to overhaul your existing one. That should be even cheaper and give you back original RPMs.

Talking of the electrical AAVs that were typically installed in K- and L-Jetronic: There were also plenty of versions like in collant AAVs. And they have various air flow profiles. They are not produced any more today and I do not thnik that it would be easy to find an AAV with the same air flow profile. And that is exactly what you see. You wonder why RPM is low in cold start.

Hi Volker,

I did start the engine cold--about 4°C--and there was airflow through the cold start auxiliary valve. So it is not stuck or defective, but perhaps not the proper calibration for the B20F. The kit must include a valve for another application (who knows which one?).

I think that I will stay with the current setup for now as the car starts well enough. I would like to have the original wax pellet valve rebuilt. Can I send it to you for repair? I value originality and have tried to maintain this throughout.

Thank you and best regards,

Glenn