I have a ’78 Mark V, with a 400 engine, from California. It has become very hard to start at times when cold. It will turns over fine. When trying to start I depress the pedal to the floor and slowly release as per the owners manual. The car almost starts but won’t run. On the second attempt I have tried holding the pedal to the floor, 1/4 throttle and not depressing the throttle but no go. When I leave it for about an hour it fires up great without touching the pedal. It acts as though it is flooded but holding the pedal to the floor does not allow it to start. When warm it starts great and when it does start it runs fine. I have pulled the spark plugs out when it won’t fire and they do smell of fuel. The plugs are correct as per the local Ford dealership. It has an electric choke. Does the choke need adjustment? It did start just fine, seldom on the first attempt but always on the second attempt. The ambient temperature has gone up since I bought the car, early spring temps were around 0-5 Celsius to 15-20 Celsius. Could this also be a factor?
Hi Carman –
Welcome to the forum. The first check for this problem is to remove the air cleaner before a cold start and observe the cold choke operation while manually operating the accelerator linkage. The choke butterfly valve should snap closed to allow for a fast start with a rich mixture and then open slightly upon starting and continue to slowly open fully as the engine warms up. If the choke circuit is o/k and requires no repair then you must check to find out if you have fuel immediately available in the carburetor. If not, a fuel pump and fuel system test is in order.
For a cold engine we usually give the accelerator pedal a couple of quick pumps to set the choke, the fast idle and to pump some fuel through the carb for a rich mixture and a fast start. Assuming that your ignition and other” tune up” components are in good order you must also have the proper choke and fuel operation as described above. I hope that the above helps you to future quick starts.