QuestionI have been battling this problem for more than 3 years now, so hopefully you can shed some light.
I am having difficulty starting my 1995 Discovery 3.9 Fuel Injected. Almost always starts when engine is cold. Once warm and has been off for more than 30 mins, engine cranks several times and will not start unless I pump the gas pedal radily while engine continues to crank. If I do not pump the gas pedal while cranking, the engine will NEVER start. Once started, it runs good and remains started - never stalls out randomly. The warm engine will start right up if attempted within 15 minutes after shutting it down. Is the fuel slowly draining back into the tank causing me to pump pedal inorder to get it back to the engine?
Can you help me determine the faulty part/what needs replacing? Does this have anything to do with one of the many sensors fuel/oxygen/coolant)? Seems odd that the problem only occurs when engine is warm. Is there anything that shuts off the fuel pump during ignition when the engine is hot?
I have replaced: fuel filter, fuel pressure regulator, all breather hoses, air filter, starter
battery, plugs, wires, dist cap/rotor. The dealer found no faults in voltage or pressure, but may not rule it out.
Long message but lots of background, trial and error.
AnswerI think it will be the coolant temperature sensor. Be cause if it gives a hot signal all times, the engine work fine in hot, but the mixture will too lean in colder engine.
Try to measure resistance between the two pins (hot and cold too), then write me.
