I have 1999 V10 Ford chassis on a 2000 Coachman motorhome. Engine starts great when cold, runs great, idles great, no skipping, missing, etc. Problem is that after driving more than 30 minutes or so it won't start, cranks but will not start until it has set long enough to get cold again. Computer code says lean fuel. Mechanic who ran codes had no idea as he checked and I heard him tell his coworker that it was getting plenty of fuel. Please help.
In fuel-injected systems, hot-start problems indicate that the fuel line is unable to maintain pressure.
This could be due to a few things related to the fuel supply line, including:
- a leaky fuel injector
- minute cracks in the fuel line which leak fuel when under pressure
- a bad non-return valve in the fuel line which is allowing pressurized fuel to flow backwards
The reason why this happens only for hot starts is because the fuel is more likely to vaporize as temperature increases. In order to avoid vaporization problems the fuel lines are expected to be pressurized during a hot start.
Jan, I also have a V10 with the exact same problem which I haven't remedied yet but I have figured out a simple answer around the problem. Cycle the ignition switch (key) off and on two or three times (without engaging the starter) and in doing so the fuel pump will force the fuel rail to fill with fuel and then turn the key to start the motor.....it works every time, no matter if the engine is hot or not.