Cold start problem
#1
11-20-2005, 01:38 PM
Cold start problem
I have a 99 ranger 2.5l. On cold mornings or after the truck has been sitting for a while on a cool day, engine will crank but not turn over. There is no fuel at the schrader valve on the fuel rail when this happens. Fuel pump soumds like it is working sometimes others not but this only happens when the engine is cold.
#2
11-20-2005, 05:27 PM
#3
11-21-2005, 07:39 AM
The fuel system is supposed to maintain fuel and pressure in the fuel rail all the time. If it doesn't, then either you have a leak, a leaking injector(s), or the check valve in the in-tank fuel pump is defective. Any of these allow a leak-down over time, which agrees with the engine being cold, you had to leave it for a while...
A test you can run to see if this is the problem (leakdown) is to operate the ignition switch from off to on (not start) multiple times to get the 3-second run of the fuel pump that is supposed to occur immediately after you turn the key to 'on'. That will in effect run the pump as many times as you cycle the switch. (this is the recommended 'priming' procedure in the owners manual if you run out of gas). If the engine starts and runs better, you need to figure out which 'leak' is occuring. In the older designs you could pinch off the fuel return line and see if the system maintained pressure. IN the returnless systems, I am not too sure what you'd do, but they would only have a check valve in the pump, so I guess it narrows down the possibilities.
Leaking injectors would cause a cloud of black smoke on startup, and probably poor running until the extra fuel clears.
tom
A test you can run to see if this is the problem (leakdown) is to operate the ignition switch from off to on (not start) multiple times to get the 3-second run of the fuel pump that is supposed to occur immediately after you turn the key to 'on'. That will in effect run the pump as many times as you cycle the switch. (this is the recommended 'priming' procedure in the owners manual if you run out of gas). If the engine starts and runs better, you need to figure out which 'leak' is occuring. In the older designs you could pinch off the fuel return line and see if the system maintained pressure. IN the returnless systems, I am not too sure what you'd do, but they would only have a check valve in the pump, so I guess it narrows down the possibilities.
Leaking injectors would cause a cloud of black smoke on startup, and probably poor running until the extra fuel clears.
tom
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