Rough idle

db6431

New Member
Hi all
My 1976 2200sc has recently started idling a little rough and miss firing as I accelerate through the gears. He starts first time cold or hot and will sit at 60 mph on the motorway with no problems, but then will miss fire and kangaroo as I go up through the gears.
Any ideas what to check first
Thanks
 
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Have you got a fuel filter fitted? If not for one and check if there’s dirt in the fuel. If you do, check it for blockages.

Second choice would be to look at points and condenser if conventional ignition is still fitted. See if the spark is weak.
 
Thanks, will check that, previous owner fitted all new ethanol friendly fuel lines, mechanical pump and electronic distributor, also rebuilt the carb, he recommended Shell Vpower but I last filled up with Sainsburys super unleaded, the car was sat not running for a long time but I've put over 1000 miles on it in my 14 weeks of ownership, hopefully a touch of dirt will just work it's way through.
 
I would fit a filter if none is present. Try pulling out the choke under full throttle, that can clear blockages.
 
I would fit a filter if none is present. Try pulling out the choke under full throttle, that can clear blockages.
Also try the reserve fuel line. If there is a constriction in the main fuel line then this could cause some of these symptoms.

Also inspect the high tension wires for signs of chafing.
 
Also try the reserve fuel line. If there is a constriction in the main fuel line then this could cause some of these symptoms.

Also inspect the high tension wires for signs of chafing.
To add to the reserve fuel line point, check that the reserve tap inside the engine bay is engaged fully in either position. Sometimes when pulling out the reserve leaver from inside and pushing it back in doesn't necessarily push back the tap back in place. This can lead to partial fuel starvation on load.


Richard
 
To add to the reserve fuel line point, check that the reserve tap inside the engine bay is engaged fully in either position. Sometimes when pulling out the reserve leaver from inside and pushing it back in doesn't necessarily push back the tap back in place. This can lead to partial fuel starvation on load.


Richard
Good point, I had decided not to use the reserve but then advised to use it regularly whether you need to or not so I had pulled it out for 5 mins before getting the issue, might pull it out again and push it back just to make sure its seated correctly
 
Good point, I had decided not to use the reserve but then advised to use it regularly whether you need to or not so I had pulled it out for 5 mins before getting the issue, might pull it out again and push it back just to make sure its seated correctly
You can manually check the valve pretty easily on the four cylinder cars. Its mounted on the right hand inner wing just in front and below the steering box on UK cars or the idler if your car is RHD. You'll see the cable going to a small lever. Pust the reserve knob in, then go under the bonnet and grab the lever and pull it away from the cable to ensure it is fully in the none reserve position.
 
Good point, I had decided not to use the reserve but then advised to use it regularly whether you need to or not so I had pulled it out for 5 mins before getting the issue, might pull it out again and push it back just to make sure its seated correctly
You will need to check from inside the engine bay . The tap works through 90 degrees and sometimes gets stuck half way through.
 
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