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  • zaken1 09/13/12 7:13 pm PST

    Just having pressure from the fuel pump does not prove there is nothing else wrong with the fuel system. The fuel injector also has to be triggered at the right point, and be held open for the proper length of time; the fuel filter must allow fuel to flow freely, and the fuel pressure has to be within the maufacturer's specifications, The quick and dirty way to test this is to buy a can of engine starting fluid; and disconnect the air duct hose from the throttle body. Prop the throttle butterfly partly open, and spray a 2 second burst of starting fluid into the throttle body air inlet. Then quickly release the throttle, slip the air duct hose back in place (don't bother to tighten the hose clamp at this time) and try to start the motor. If it fires or starts briefly and then stalls; the engine is starving for fuel. If starting fluid does not make it at least fire; then this is not a fuel system problem.

    If starting fluid makes it fire; replace the fuel filter and the intake air temperature sensor. If it still doesn't start; replace the camshaft position sensor (which generates the signals that trigger the fuel injector).

    If starting fluid does not help at all; this is either an ignition problem, or the timing chain has broken or jumped out of position. Here's how to proceed from this point: Take off the distributor cap, and watch the rotor while the starter runs. If the rotor spins while the starter runs; the timing chain has not broken (but it still may have jumped out of position). If the rotor does not turn while the starter runs; the timing chain has broken and must be replaced.

    If the rotor spins when the starter runs; then disconnect the distributor cap end of the spark plug wire that comes from the coil, and clamp or hold the wire at least 3 inches away from the end; so that the end you disconnected is about 1/4 inch from the engine block. Then run the starter and see if there are sparks jumping from the wire to the block. If there are no sparks from the coil wire when the starter runs; replace the ignition module and the crankshaft position sensor. If still no sparks after the module and CPS have been replaced; replace the ignition relay and the distributor ignition pickup, and if still no sparks, replace the coil.

    If there are sparks jumping from the wire; run a compression test on at least 4 cylinders. If there is less than 120 psi compression in all the cylinders; the timing chain has jumped out of position and must be replaced. If there is more that 125 psi compression in all cylinders; replace the distributor cap and rotor; install a new set of Champion #7940 plugs, and a set of Bosch #09791 plug wires.

    To ask further questions; or to post additional information; click the "answer this question" button below this response, type your message in the box which appears, and click the "submit answer" button.

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