Thank you for providing a lot of good observations. When you tested for voltage from the ASD relay, where you cranking the engine? You should get the 12 volts to the coil(s), injector(s), fuel pump or pump relay, alternator field, and O2 sensor heaters only for two seconds after you turn on the ignition switch, then the relay will turn back off until the engine computer sees engine rotation, (cranking or running). You might be able to hear the two-second burp from the fuel pump, but you won't be able to hear it while cranking.
The camshaft position sensor is a likely suspect, and it's very common for them to become heat-sensitive. It's on the driver's side of the head. When the pulses stop showing up at the engine computer, the computer thinks the engine stopped running, possibly due to a crash, so it turns the ASD relay off so the fuel pump won't pump raw fuel onto the ground if a line ruptured. There's also a crankshaft position sensor on the back of the engine, but they seem to cause less problems.
These sensors will usually cut out suddenly, not gradually like you described. Did you install a new pump or a used one? If a used one, it could have a plugged pickup screen. They will cause your symptom, then when it sits for a while, the collapsed screen will slowly expand and allow fuel to pass for a while. They act up more often when the largest volume of fuel is moved, which is, ... COASTING from highway speeds. (This is not the same as the tiny amount of fuel actually flowing through the injectors).
Caradiodoc
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Tuesday, April 28th, 2009 AT 4:19 AM
