BobG Posted September 24, 2014 Share Posted September 24, 2014 I'm new the driving "older" cars (pre-fuel injection) and have some trouble starting my 72 Z in the morning. I let the fuel pump work for a minute, adjust the choke, then crank the engine, usually to just hear it crank. It takes two or three tries before the engine turns. Is this usual from a cold start with carbuerators? Once it gets going, it idles rough for a minute and then runs fine. It seems once it sits overnight and fuel sits still, the Z doesn't enjoy waking up. Thoughts? Is there something I'm missing or could do differently? Quote Link to comment Share on other sites More sharing options...
djwarner Posted September 24, 2014 Share Posted September 24, 2014 It would be helpful to download an Owner's Manual. Quoting: "Engine Warm - If the engine is relatively warm, the choke may not be used. Just depress the accelerator pedal down about one-quarter of its full stroke, and turn the ignition key to "START". When the engine starts running under its own power, release the key, It will spring back to the "ON" position automatically." "Engine Cold (Cold Weather) - With a cold engine, pull out the choke control lever all the way, depress the accelerator pedal slightly, and start the engine. As soon as the engine starts, return the choke control lever in far enough to keep the engine running smoothly. Then push it in all the way when the temperature gauge pointer begins to move toward its normal operating range. Do not drive steadily with the choke control lever pulled out. This may result in excessive fuel consumption." What this does not say is to release the accelerator pedal to prevent over revving the engine. These instructions were fairly standard for carbureted engines. Quote Link to comment Share on other sites More sharing options...
z240 Posted September 24, 2014 Share Posted September 24, 2014 Bob, you car is running well. Enjoy it for what it is. Carbs are just nothing like modern cars. It actually takes work, patience and effort to start them and use them until the engine is warmed up. They are likely out of tune and dirty to some degree, the chokes may not be working quite so perfect, so there is certainly more you could do. Look at ztherapy.com and get their DVD about how to tune them. Quote Link to comment Share on other sites More sharing options...
BobG Posted September 24, 2014 Author Share Posted September 24, 2014 OK thanks for the info... just a different feeling with an older car. Quote Link to comment Share on other sites More sharing options...
Tony D Posted September 24, 2014 Share Posted September 24, 2014 It's a "STARTER CIRCUIT" gentlemen, it is NOT a choke. Two different things altogether. If you have a 73 or a 74 model, THEY have a "choke".... otherwise you just pull down the jet in the carb well to expose more annulus to engine vacuum and suck up more gasoline under suction dome down, cranking vacuum. If all is adjusted correctly, the throttle plates should open incrementally when the Starter Lever is engaged anyway...and you will get a 1,700 or so fast-idle when it starts. If you don't have the manifold preheating, and carburettor water circuits enabled, and have plugged them, your cold running and drivability will be markedly worse than on a stock car...for no real performance gain whatsoever. What a deal, huh? Quote Link to comment Share on other sites More sharing options...
Miles Posted September 24, 2014 Share Posted September 24, 2014 (edited) Go here and read the entire website on SU carbs: http://www.ztherapy.com/ Also, buy the video "Just SUs". It will explain everything you need to know about maintaining the SU carb. Edited September 24, 2014 by Miles Quote Link to comment Share on other sites More sharing options...
thedarkie Posted September 25, 2014 Share Posted September 25, 2014 (edited) Just pump the throttle once or twice before cranking on a cold start... Edited September 25, 2014 by thedarkie Quote Link to comment Share on other sites More sharing options...
Leon Posted September 25, 2014 Share Posted September 25, 2014 Just pump the throttle once or twice before cranking on a cold start... That does absolutely nothing for SUs. Quote Link to comment Share on other sites More sharing options...
Tony D Posted September 25, 2014 Share Posted September 25, 2014 There is a stick. We hit people with it. It is reserved for those who suggest pumping the pedal on a carburettor with no accelerator pump does anything worthwhile except make sure the linkage is free, and returns to origin. Where is this stick? It's whackin' time! Quote Link to comment Share on other sites More sharing options...
thedarkie Posted September 28, 2014 Share Posted September 28, 2014 Learn something new every day In that case, secret option #3: switch to EFI Quote Link to comment Share on other sites More sharing options...
Tony D Posted September 28, 2014 Share Posted September 28, 2014 Whackin' Stick is also used on people who don't read their Ford Owner's Manual and pump the accelerator to the floor with the key on, before cranking it....putting it in "flood clear" and repeat it until the battery is dead... I got that one called into me and was embarrassed explaining it doesn't work like that any more.... and hasn't for some time! What can you say, everything sucks but Matlock and I still wear an onion on my belt while taking the walking bird out for evening constitutional! Quote Link to comment Share on other sites More sharing options...
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