Is it your solenoid or are you just happy to see me?

[E21noob]

Hi guys.

Any chance for some ideas on why my 316 is running super high on idle?

Quick story is: car was running ok, took the solex out, put a weber in, took the weber out (to go in other car more on that later), put the solex back in, starts and everything fine but even when warn keeps running super high revs on idle. When I disconnect the electrical connection from the solenoid, idle goes low but very uneven, when I reconnect idle goes back up high.

Does the solenoid on the solex need replacing?

Cheers, appreciate your help

[BertjeConti]

Is the throttle linkage ok?
Seems like throttle doesn't come in full closed position.
Does your solex have a vacuum valve that opens the throttle a little when starting, and is the corresponding vacuum hose leaky ?

[E21noob]

Yes, checked that. The linkage goes all the way back. Unscrewed the idle adjustment on the linkage all the way up so it wasnt in contact at all.

I did check the vaccuum hoses but cant be sure... Would an unconnected vaccuum hose cause these symptoms?

Reason I reckon its the solenoid is that the temp gauge shows correct in the car.

[BertjeConti]

I don't see any connection between the solenoid on the solex and the temp gauge?

The solenoid is a electric valve that enables fuel delivery for idling, it is a on/off valve. Normally when the engine idles and you'll cut the power to the solenoid the engine should stall.
The purpose of the solenoid is to stop fuel delivery when you shut down the engine.

In your case the engine gets more air (and fuel) than it should get with the throttle closed. You'll have to check if throttle is fully closed. The engine gets to much air and fuel when idling, thats for shure. So there must be a reason the throttle is lifted a little bit. thats the direction to go.

[E21noob]

Ah ok. I got something wrong then. To me it looked like it was connected to the temp gauge but must be mistaken.

I'll have a second look at the linkage, but pretty sure it's as far down as it can go.

I'll report back!

[Rocket356]

Did you find a solution to this in the end? I've got the same issue - when I bought the car home there was a period when it ran (uneven) at about 800rpm but now, even when warm, it idles at about 1,600rpm. It sounds like a similar issue to yours. I was going to warm it up and then follow the Haynes procedure for setting the idle speed, but it sounds like something else might be amiss.

[E21noob]

No, not yet. The car is in storage, and havent been down to do anythig about this since I parked it there.

Plan is to go with Bertje's idea and look closer at the throttle linkage.

[Rocket356]

OK, cool. Well, when I get time in a day or two I'm going to have a look over mine and I'll let you know if I find anything.

[Rocket356]

E21noob - I drove to my workshop yesterday and by the time it I got there, the car was at full operating temperature and idling at about 1,700rpm. I switched it off, opened the bonnet and started it back up, watching the throttle lever as I did. As soon as I started it I saw the throttle open itself back up - or the auto choke or vacuum or whatever it is that opens turns the throttle spindle on it's own. You might want to see if yours does that.

Could the auto choke be stuck on? When it's 'idling' (at 1,700rpm...) it has an occasional miss. There's also a hissing/whistling sound which is a lot louder with the air cleaner taken off.

I don't want to hijack your thread but it may be that we have the same issue and what solves it for me might also solve it for you!

[E21noob]

No worries about the thread!! I see you have started a new one, will follow that and see what happens.

Wont get to look at mine for a while yet. Winter over here...salted roads...not great for an old E21