more idle problems

[dimmer]

Okay now I am getting frustrated
A 74 1.8 914 L-jetronic

The car idles and runs great. Only one problem, if I put in the clutch when driving, the car will not return to 850 rpms, it stays up around 1200rpms. If it is at 1200 and I take off again I get some valve noise. If I use the engine to slow down and put the clutch in just before the car dies, it idles fine.

I have checked the following
accelerator cable to ensure not binding.ok
replaced points, rotor, condensor, cap, fuel filter etc
checked aux air and decel valves- ok

I did find one thing. In reading the factory shop manual it says to disconnect the vacuum lines when setting the timing. When I do that my rpms jumps up about 500 rpms. If I then time the car and put back the vacuum lines the car barely idles.

As a result I have timed the car with the vacuum lines on.

I am beginning to think my retard on my vaccum advance may not be working?

Any ideas would be helpful.

Happy Fathers Day!!

[Dave at Pelican Parts]

Try plugging the vacuum hoses instead of disconnecting them.

--DD

[dimmer]

Thanks Dave
I tried plugging the lines. The idle still jumps up about 500rpms to around 1300. I have it timed with the vacuum hoses on. Could I take off the vaccum hoses, time the car, put the hoses back on and then increase the idle. My feeling is this will make the car run hot?

[Dave at Pelican Parts]

I meant to plug the hoses when you set the timing. Disconnect and plug them. Keeps air from getting into the intake, causing a lean mixture and often a higher idle.

--DD