alan.gilbert_6384 Posted October 30, 2022 Report Share Posted October 30, 2022 Hi All at Tssc, I know this will seem obvious to the majority of you guys, but I had loads of spark plug issues until I realised what I was doing wrong. Later I found this video which is very helpful to us less experienced users, please let me know what you think. So for my spitfire 1500, from cold, coke is all the way out, then as soon as it fires this goes in to about 1/4 of the travel, to just before the fast idle position. This stops the plugs getting fowled up on the over rich mixture. Link to comment Share on other sites More sharing options...
Jeffds1360 Posted October 30, 2022 Report Share Posted October 30, 2022 I have not watched that whole video. But my experience is that full choke is only needed on a stone cold engine with Air temperature well below 10C. NO choke if engine is warm. Temps just now are circa 12-15 and my cold engine stars with 1/2 choke and straight in to 1/4. Remember if car stood for a day or two and you have a mechanical fuel pump, it can toke a dozen or two cranks to get fuel to the carb/s. If this is the situation, leave choke off until fuel through. If electric pump, listen and wait 'till pressurised. What is/was your problem with plugs? Link to comment Share on other sites More sharing options...
alan.gilbert_6384 Posted October 30, 2022 Author Report Share Posted October 30, 2022 38 minutes ago, Jeffds1360 said: I have not watched that whole video. But my experience is that full choke is only needed on a stone cold engine with Air temperature well below 10C. NO choke if engine is warm. Temps just now are circa 12-15 and my cold engine stars with 1/2 choke and straight in to 1/4. Remember if car stood for a day or two and you have a mechanical fuel pump, it can toke a dozen or two cranks to get fuel to the carb/s. If this is the situation, leave choke off until fuel through. If electric pump, listen and wait 'till pressurised. What is/was your problem with plugs? Hi, they would black up with carbon due to the over rich mixture of too much coke after initial start up, this would cause a miss fire and rough running and sometimes permeant damage to the plug. I only realised this after inspecting the plugs and using a spark plug cleaner (pic attached). This was also after many hours with a colour tune to make sure the mixture was right when hot. This cold start method stopped the fowling of the plugs and is much better now. Link to comment Share on other sites More sharing options...
Jeffds1360 Posted October 30, 2022 Report Share Posted October 30, 2022 Good. You do not say what car you have but you must ensure that pulling the choke on causes the throttle to open too. There is a screw adjuster on to a cam beside the cable. Revs go up massively with more than 1/4 CHOKE and you certainly know when to push it back in !!. Hope you are not on this Coke you keep mentioning, unless it is cola !!?? 1 Link to comment Share on other sites More sharing options...
Pete Lewis Posted October 31, 2022 Report Share Posted October 31, 2022 many plugs now made do not have the porcelain glazed this allows rich mixture to contaminate and breakdown the spark there has been lots of discusion it seems bosch still glaze the insulator and a few went to W78 but they are not overly available you dont want plugs with any R in the suffix as the resistive nature does reduce our low HT some used them but there are many a misfire found to be R plugs not helping matters Link to comment Share on other sites More sharing options...
Neil Clark Posted October 31, 2022 Report Share Posted October 31, 2022 Living in Manchester 50 years ago on the Mini's it used to be full choke to get started then in a bit as soon as the engine would run on a little throttle and gradually push it in until it didn't stall. Growing up in Glasgow in the 50's my Dad would wait until the temp gauge on his A70 moved a touch to be sure the oil etc was warmed up before driving off, he said it was to reduce wear but I've no idea if that is an old wives tale or not. Link to comment Share on other sites More sharing options...
foshi Posted October 31, 2022 Report Share Posted October 31, 2022 better to start on choke drive the car push the choke in as soon as the car will run with out it less engine wear that way . Link to comment Share on other sites More sharing options...
NonMember Posted October 31, 2022 Report Share Posted October 31, 2022 13 minutes ago, foshi said: better to start on choke drive the car push the choke in as soon as the car will run with out it less engine wear that way . I'm not sure it's less wear that way but it certainly causes less trouble. If you let it warm up at idle then it takes a long time and cokes up the cylinders. If you drive with full choke for longer than you need to then you can get bore washing (petrol dilutes the oil) and significantly increased wear. So the "start up and drive off" method is best, but try not to drive it too hard until the oil is warmed up a bit. Link to comment Share on other sites More sharing options...
Iain T Posted October 31, 2022 Report Share Posted October 31, 2022 I've set my choke so when fully open tick over is about 1200 rpm and the enrichment discs (CDS150 carburetor) are fully rotated. I started the car after a six week layup and albeit with an electric pump it started on the second go. I then push the choke in half way. Seems to work......so far🤞 Iain Link to comment Share on other sites More sharing options...
foshi Posted October 31, 2022 Report Share Posted October 31, 2022 sure less wear engine gets to temperature lot quicker when driven can push the choke home a lot quicker than sat at idle Link to comment Share on other sites More sharing options...
johny Posted October 31, 2022 Report Share Posted October 31, 2022 I think some moderns now have controlled radiator shutters which stay closed when you drive off until the engine is up to temperature - something else to go wrong of course😮 Link to comment Share on other sites More sharing options...
Pete Lewis Posted October 31, 2022 Report Share Posted October 31, 2022 we fitted varivane automatic shutters thro the 60s 70s 80s to trucks of the day you do have to be careful with cavitating air if the fan cant suck from anywhere metal fan blades used to fracture and fly off so blanking radiators can cause serious failures Pete Link to comment Share on other sites More sharing options...
Wagger Posted October 31, 2022 Report Share Posted October 31, 2022 If the thermostat is working properly it should not be necessay to blank the radiator. The Wolseley 1500 (1958 to 1965) had a radiator blind that was cable operated from the dashboard. My pal had an overheat because he forgot to release it. My Vitesse has never needed full choke to start beause it is in an attached garage.. Many of us have been caught out buying low mileage cars in the past that have never travelled far enough for chokes and enrichment devices to be turned off. In a previous club a 20,000 miler had worn out bores due to fuel washing the oil away. Start, push choke in to about a quarter, drive off asap and shove hard against the dashboard as soon as possible. 1 Link to comment Share on other sites More sharing options...
johny Posted October 31, 2022 Report Share Posted October 31, 2022 I reckon the thinking these days is that youre cooling the contents of the radiator as you drive even though the thermostat is closed so the auto shutter system is to stop that... Link to comment Share on other sites More sharing options...
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