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Post Number: 1
|Posted on Thursday, 04 June, 2015 - 04:43 am: |
My 79 shadow had a problem a couple weeks ago and had to have a tow home. I changed the solenoids and weekener valve. It started okay but now it won't turn off. I have taken apart the switch box and all seems okay... except.. there is a copper band insulated in yellow rubber that does not seem to have electrical continuity. I have a spare part and will be putting it on. Is there something else that could be causing the car not to be turned off? I can't see any bad wires where I was working on the solenoids.
Post Number: 1342
|Posted on Thursday, 04 June, 2015 - 04:54 am: |
Just for clarity, when you say "won't stop running" and "not to be turned off" are you saying it literally keeps running as though the key were still in the "Run" position and you could drive it away without problem, or are you saying that the engine won't shut down and is dieseling after you turn the key off?
Post Number: 216
|Posted on Thursday, 04 June, 2015 - 04:59 am: |
The forward solenoid on the weakener is the anti-run-on valve. It exposes the carburetor float chambers to intake manifold vacuum, depressing the fuel level and starving the engine.
So if the car is dieseling after shut-off, that'd be my first port of call....
Robert Noel Reddington
Post Number: 44
|Posted on Thursday, 04 June, 2015 - 05:34 am: |
I am glad my car 1974 UK spec. Doesn't have anti dieseling valves and other junk fitted.
To check the switch box connect meter to ignition coil and turn ignition off and on. Or on and off.
Post Number: 262
|Posted on Thursday, 04 June, 2015 - 09:16 am: |
"I am glad my car 1974 UK spec. Doesn't have anti dieseling valves and other junk fitted."
And I'm glad my 1975 one no longer does.
Running-on is usually caused by hot spots in the combustion chambers. It could be carbon deposits, wrong type of spark plug, lean mixture, engine running too hot, idling speed too fast, etc.
gordon le feuvre
Post Number: 74
|Posted on Friday, 05 June, 2015 - 05:33 am: |
You need to confirm how long engine keeps running -is it 20 secs or 5 mins. A chassis no. would help. Is engine idle "normal" during this period or having dieseling effect?
Robert Noel Reddington
Post Number: 49
|Posted on Friday, 05 June, 2015 - 07:05 am: |
My SRH 17768 has no aircon idler no damper or no kick down switch fitted to the carbs. No emission control apart from the engine breather which breathes into the choke housing rather than the inlet manifold as on some cars.
This gives good vacuum for the carbs to work with.
Emission controls seem to make engines less than willing at low rpm.
If legal I would remove the extras.
I found in the 1980s cars developping running on. The mixtures were so weak at idle.