Main Menu

hard cold start


Vehicle Information: Model: 911t; Year: 1970; Body Type: Coupe; Engine (type, size, modifications): 2.2 carburated; Total Mileage: 138000miles;

I have owned this car for twenty years and after at least ten years decided to put it back on the road. I have rebuilt the motor cleaned out the tank,filters,stripped the carbs,cleaned them with commercial thinners it removed all the fuel gunk of ages including a lot of carbon build up, blown out the orifices,nice word that,fitted a new fuel pump, timing is right ,I checked the valve timing three times and the ignition is spot on. Problem the car is hard to cold start .It has zenith 40 tin carbs without the emission control enrichment device,as basic as a carb could be .They are as clean as can be,in reasonable condition for the age with a little bit of spindle wear on no1 and 4 chokes because thats where all the work is done, cranking speed is good and sparks are good ? but to cold start i have to pump the pedal a lot of times the accelerator jets squirt in a few ccs af gas then, as she catches i just keep pumping the gas pedal till the motor gets up to 3 to 6 thou i keep it there by same meams until the motor is a little bit warm, then foot off and it sits nicely at tickover.when hot the motor catches first time and shes happy to rev til she busts (lost the rev limiter many years ago). Carbc are balanced mixture screws two and a half turns out,I have not verified the fuel level in the float chambers but theres plenty there when you pull the carbs apart and i guess that wear will only lead to an excess of gas wich probably help start up. I have tended to concentrate on carburation as the reason i stopped driving it was persistent misfiring through the carbs which was only a weak mix miss due to dirty jets but the valve guides and valves were very not in the best condition when the motor was stripped. I'm sure it started better than this in the distant past but you know what memory is like. Hope you can help.

You must log in to view answers associated with technical questions. Join PCA to participate in our community.
No votes yet