Fuel pressure is misleading because the fuel pump will run for one second when the ignition switch is turned on. What is missing ninety five percent of the time is it fails to resume running during cranking. Spark will be missing too for most crank/no-starts.
The place to start is by determining if the automatic shutdown, (ASD) relay is turning on. The easiest way to check that is to measure the voltage on the dark green/orange wire at any injector, the ignition coil pack, or either smaller terminal on the back of the alternator. A test light works best because digital voltmeters do not respond fast enough. You should see the test light turn on for one second when you turn on the ignition switch. What is important is it must turn on again during engine rotation, (cranking or running). If it does not, the crankshaft position sensor is the best suspect, but first read the diagnostic fault codes.
Be aware that cam and crank sensors often do not set a code for a missing signal just from cranking the engine. They commonly only set while a stalled engine is coasting to a stop. You lost that information when you replaced the engine computer. If there is no fault code related to the no-start, it becomes necessary to use a scanner to see if either sensor is shown as missing its signal.
Tuesday, January 3rd, 2017 AT 5:46 PM