Hard to Start
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Joined: May 2006
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Hard to Start
I have 90 E-150 with 5.8 L and it is almost impossible to start when the engine is cold unless I hit it with a little ether.(I know, A bad thing) Once I have it started and it warms up. It will start right over. Changed Fuel filter, rotor, cap, and it seems to have plenty of spark.
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Joined: Apr 2005
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It could be a number of things, even beyond what I'm going to recommend...
First I'm thinking that you could have a temperature sensor problem. The fuel mixture is not rich enough to start. If the computer sees a temperature sensor that says the engine is already warm, it's going to produce a mixture too lean for cold starting. I'm not sure about yours, but I know on a lot of vehicles there are two different temp sensors, one for the computer and one for the gauge. They gauge might read right and the signal to the computer still be wrong.
Another possibility is that the fuel system is not keeping prime. When the engine is off, the fuel system is supposed to stay fairly well pressurized. If the pressure is bleeding off due to a faulty check valve, you'll have insufficient fuel pressure to start. Using the ether provides an alternative fuel source to start the engine, and once it starts, the fuel pump starts cranking full time, quickly providing enough pressure to keep it running. Once the fuel system's been pressurized, the pressure bleeds off slowly enough that it'll restart within a shorter period of time. However, left long enough, the pressure eventually goes away. You're attributing the starting problem to the temperature of the engine, when it may be the time since its last start that's the issue.
Try this: Next time you try a cold start, turn the key to the run position (not start) for about 5 seconds, then turn it off again. Repeat that about 10 or 20 times, then try to crank the engine. See, when you first turn the key, the fuel pump runs for a brief time to pressurize the system, then shuts off until the engine fires. If there's little to no fuel in the lines, it'll take a lot more priming than normal. Each time you turn the key on, it'll run the fuel pump again, adding more fuel to the system. If it's a fuel pressure problem caused by a faulty check valve and insufficient fuel pressure, this little test should show you.
First I'm thinking that you could have a temperature sensor problem. The fuel mixture is not rich enough to start. If the computer sees a temperature sensor that says the engine is already warm, it's going to produce a mixture too lean for cold starting. I'm not sure about yours, but I know on a lot of vehicles there are two different temp sensors, one for the computer and one for the gauge. They gauge might read right and the signal to the computer still be wrong.
Another possibility is that the fuel system is not keeping prime. When the engine is off, the fuel system is supposed to stay fairly well pressurized. If the pressure is bleeding off due to a faulty check valve, you'll have insufficient fuel pressure to start. Using the ether provides an alternative fuel source to start the engine, and once it starts, the fuel pump starts cranking full time, quickly providing enough pressure to keep it running. Once the fuel system's been pressurized, the pressure bleeds off slowly enough that it'll restart within a shorter period of time. However, left long enough, the pressure eventually goes away. You're attributing the starting problem to the temperature of the engine, when it may be the time since its last start that's the issue.
Try this: Next time you try a cold start, turn the key to the run position (not start) for about 5 seconds, then turn it off again. Repeat that about 10 or 20 times, then try to crank the engine. See, when you first turn the key, the fuel pump runs for a brief time to pressurize the system, then shuts off until the engine fires. If there's little to no fuel in the lines, it'll take a lot more priming than normal. Each time you turn the key on, it'll run the fuel pump again, adding more fuel to the system. If it's a fuel pressure problem caused by a faulty check valve and insufficient fuel pressure, this little test should show you.
