engine and drivetrain dcoe question

[Hugh]

when the car is stopped and idling, how long should it take for the rpms to go back to idle when you rev the engine once? it seems to take about 10 seconds on my set. Even with the cable completely disconnected so its not the linkage binding.

Is this normal?

[steve k.]

do you have return sptings on the linkage? carb might not be able to return fast on it's own and will need help.

steve k.

[TobyB]

It should drop like a stone. Well, maybe a little slower with a stock flywheel,

but not much.

If the springs aren't the culprit, check for air leaks. I had a cracked o-ring on the isolator, and had to add fuel to match. It made the car 'idle up' a bit, at odd intervals...

fwiw.

t

[Hugh]

how might I check for the air leaks?

[TobyB]

well, now, that's a trick, isn't it?

On a 'normal' carb, you can use an unlit propane torch- wave it around where you think there might be a leak, and the car will idle up if there is.

On the dcoes, they pull air from right around where you might expect 'em to leak, so it's harder.

I found mine by pullin' em off and looking at the seals...

fwiw,

t

[Hugh]

thanks Toby,

where in Seattle are you?

I'm in the CD.

the thing takes like 10 seconds or so to return to idle...and it's not the spring.

I don't know enough about these things...they are complex. I'll take a look.

[dapbmw]

internal return springs might be broken. remove the top cover and on the bottom part in the center there is a washer that holds the spring and if the spring is missing replace it . if it is still there pull it off and see if it is in one piece. they normally break off with age. another way is to pull the carbs of the manifold and open the throttle open and it should return the close position. you can actually see it when you open the bottom cover in between the two throttle plates. springs and washers are available from www.piercemanifolds.com

dave