Hot Start problem 1986 3.6 XJ-SC
Posted: Sun Apr 17, 2016 11:02 am
For the past 20 or so years I have had a problem starting my car when hot that no one can find and I would be interested to know if anyone else as had the same thing happen to their cars The car starts perfect from cold every time but after standing a half hour or so seems to take a long time to fire up its regular serviced and maintained by Sturgess main dealers and last year they rebuild the Head due to blown gasket Over the years I have owned the car things like pressure valve temperature senser petrol pump filter distributer amplifier ecu battery sump tank cleaned have all been tried to no avail Its so annoying as I show the car and when it comes to starting it for the judge it seems to take for ever but always starts after cranking longer than it should I have read the Kirby palm Book and the page 290 below exactly describes what I have I have changed the vaccume valve EAC5086 from another engine known to be ok Fuel pressure is said to be fine does anyone have any thoughts or ideas to try BELOW IS THE EXACT PROBLEM
HOT STARTING: The fuel cooler works great when the engine is running, but is worthless after the engine is shut off. The heat rising from the engine heats the fuel in the rail, which is not moving. If the engine is started about a half hour after shutoff, it may have difficulty starting. Jaguar has provided two different fixes for this problem. Both involve a temperature sensor in the boss on the left side of the fuel rail; the boss has no opening into the fuel, but the sensor has a copper bottom that presses against the rail to sense the temperature. The boss itself seems to exist on all XJ-S H.E.’s, since a recall replaced the rail after the hot fuel problems were found. The earlier type sensor is electrical, and is connected in line with the inlet air temperature sensor for the EFI system. The later type sensor has vacuum connections, and is connected between the intake manifold and the left side fuel pressure regulator. At least one of these sensors has been known to simply fall apart, but owners have had some success simply gluing them back together. If your car doesn’t have either fix (or if it does but still has difficulty with hot starts), there is a work-around for the hot start problem. Turn the ignition key on and off several times before attempting to start, allowing the fuel pump to run for two seconds each time. This will flow cool fuel from the tank into the rail.
HOT STARTING: The fuel cooler works great when the engine is running, but is worthless after the engine is shut off. The heat rising from the engine heats the fuel in the rail, which is not moving. If the engine is started about a half hour after shutoff, it may have difficulty starting. Jaguar has provided two different fixes for this problem. Both involve a temperature sensor in the boss on the left side of the fuel rail; the boss has no opening into the fuel, but the sensor has a copper bottom that presses against the rail to sense the temperature. The boss itself seems to exist on all XJ-S H.E.’s, since a recall replaced the rail after the hot fuel problems were found. The earlier type sensor is electrical, and is connected in line with the inlet air temperature sensor for the EFI system. The later type sensor has vacuum connections, and is connected between the intake manifold and the left side fuel pressure regulator. At least one of these sensors has been known to simply fall apart, but owners have had some success simply gluing them back together. If your car doesn’t have either fix (or if it does but still has difficulty with hot starts), there is a work-around for the hot start problem. Turn the ignition key on and off several times before attempting to start, allowing the fuel pump to run for two seconds each time. This will flow cool fuel from the tank into the rail.