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A no start means that the starter is turning the crankshaft, but due to a lack of fuel, spark and / or compression the motor will not run on it's own. A no cranking condition is something totally different.
To pin down the cause of the no start, start by turning the key into the on position and listen for the fuel pumps. Take a mental note as to wether the pump primed the fuel system or not...if not then the fuel pump may be the problem. After that, remove a hose from the throttle body (ie a hose for the EVAP system) and spray some carburetor cleaner inside. Try to start the motor again. If the motor runs for a few seconds then dies you know for sure that there is, at the very least, a lack of fuel. If the motor does not start at all, then you would want to look into the possibility that there is a lack of spark. The above is what you would refer to as a preliminary test in the sence that it gets you pointed in the right direction without getting you any hard information as to what the root problem is.
If the preliminary test indicates a lack of spark, then what you want to do is turn the key to the on position, loosen the distributor, remove the spark cable from the coil and rotate the distributor while holding the spark cable about 1/4 inches from the coil tower. If a spark arcs from the cable to the coil tower then the entire igntition system is confirmed as functional and you need to look into the condition of the cap and rotor. Replace them and re-test. If no spark arcs from the cable to the tower, then you will need to look deeper into the ignition system. By the way, the reason this test is effective is because rotating the distributor with the ignition on generates a PIP pulse which leads the computer to assume start up logic. This will also activate the fuel pump relay and pulse injectors.
If the above test did not cause a spark, then you will need to check for 12 volts at the positive terminal at the coil. If 12 volts is not present, then you have either a problem with the ignition switch or a fuse like that is open. Trace the problem accordingly. If there are 12 volts at the positive terminal of the coil, then probe the negative terminal of the coil with the positive lead of an analog meter (preferably) and ground the negative lead of the analog meter then rotate the distributor left to right to left to right etc.. You should not be able to see the needle bounce between 0 and 12 volts. Rather, it should be a steady 12 volts. If the needle bounces around, replace the coil and re-test. If it is steady, then time to move onto the TFI module. The above should be done by back-probing with everything hookd up as opposed to disconnecting and probing the connector.
With the key in the on position, check for 12 volts at the TFI module. With the TFI module in the installed position, the third terminal down from the top should have 12 volts. For this you can either back probe or disconnect the module and probe the connector. If there are not 12 volts then you have an opening in the TFI ingnition wire that needs to be traced. If there are 12 volts then you have either a TFI module failure or a stator sensor failure because you have ruled out everything else. I would just replace them both because diagnosing one or the other can get rather tedious and difficult.
If the preliminary test indicates that there is a lack of fuel, then think back to wether or not you heard the fuel pump run. If so, then hook up a fuel pressure gauge and cycle the key on-off-on-off. You should get about 35 - 40 psi. If fuel pump activation is confirmed but fuel pressure readings are inadaquate, then it's time to drop the fuel tank. Once the fuel pump is removed, check the small hose that connects the pump to the feed line for a leak or rupture since that alone could cause a low fuel pressure problem. If it’s OK, replace the pump.
If you have good fuel pressure, then the no fuel condition is an injectors not opening problem. Each injector should have 12 volts with the key on. To take this measurement you will need to probe one of the two pins (usually a red wire) at the connector and a good ground (chassis ground or whatever). If there are not 12 volts then you have an opening that needs to be traced. If there are 12 volts, then hook up noid lights to the injectors and rotate the distributor back and forth (key in the on position by the way). The fuel pump should prime and the lights should blink at you. If it does blink, then the injectors are not opening yet all the wiring is good and the computer is good; this means the injectors need to be replaced. If the noid lights do not blink, then you need to perform a wire continuity test between the injector pulse signal wire and the EEC. If this wire were open, you would still get the 12 volts, but the injector would not get fired. If there is no opening or shorting of the pulse signal wire then the only thing left is the EEC itself. The EEC would need to be replaced.
If the fuel pump is not running, then locate the fuel pump relay. Make sure it clicks when the key gets turned on. If it does click, then the fuel pump output wire needs to be tested. Use a test light...if it lights up at the relay with the key on, then you need to look for an opening between the relay and pump. If it does not light up, then you need trace the always hot wire. If that wire has voltage, then rplace the relay. If it does not have voltage, then look for an opening in that wire or an open fuse link. If the relay does not click, then you replace the relay and it still does not click, then you have and opening between the ignition switch and the relay. At this point it's just a matter of finding the wire that sends voltage to the relay from the ignition switch and repairing the connection. If all is good with the relay, the wiring from the ignition switch to the relay, the wiring from the relay to the fuel pump, the constant 12 volt source to the relay and the fuel pump does not prime, then it's time to replace the fuel pump. If it still does not prime, then the only other thing that could cause the pumps to not run would be the EEC itself.
If the problem does not seem to be fuel or spark related, then a compression test is in order. Mind you, a no start condition due to low cylinder compression is usually caused by operating the motor for long periods of time with an overheating condition. A fialure in 1 or 2 cylinders will not cause a no start problem. If the no spark and no fuel test results are passed, you would need to perform a cylinder compression test and / or a cylinder leakdown test.
To pin down the cause of the no start, start by turning the key into the on position and listen for the fuel pumps. Take a mental note as to wether the pump primed the fuel system or not...if not then the fuel pump may be the problem. After that, remove a hose from the throttle body (ie a hose for the EVAP system) and spray some carburetor cleaner inside. Try to start the motor again. If the motor runs for a few seconds then dies you know for sure that there is, at the very least, a lack of fuel. If the motor does not start at all, then you would want to look into the possibility that there is a lack of spark. The above is what you would refer to as a preliminary test in the sence that it gets you pointed in the right direction without getting you any hard information as to what the root problem is.
If the preliminary test indicates a lack of spark, then what you want to do is turn the key to the on position, loosen the distributor, remove the spark cable from the coil and rotate the distributor while holding the spark cable about 1/4 inches from the coil tower. If a spark arcs from the cable to the coil tower then the entire igntition system is confirmed as functional and you need to look into the condition of the cap and rotor. Replace them and re-test. If no spark arcs from the cable to the tower, then you will need to look deeper into the ignition system. By the way, the reason this test is effective is because rotating the distributor with the ignition on generates a PIP pulse which leads the computer to assume start up logic. This will also activate the fuel pump relay and pulse injectors.
If the above test did not cause a spark, then you will need to check for 12 volts at the positive terminal at the coil. If 12 volts is not present, then you have either a problem with the ignition switch or a fuse like that is open. Trace the problem accordingly. If there are 12 volts at the positive terminal of the coil, then probe the negative terminal of the coil with the positive lead of an analog meter (preferably) and ground the negative lead of the analog meter then rotate the distributor left to right to left to right etc.. You should not be able to see the needle bounce between 0 and 12 volts. Rather, it should be a steady 12 volts. If the needle bounces around, replace the coil and re-test. If it is steady, then time to move onto the TFI module. The above should be done by back-probing with everything hookd up as opposed to disconnecting and probing the connector.
With the key in the on position, check for 12 volts at the TFI module. With the TFI module in the installed position, the third terminal down from the top should have 12 volts. For this you can either back probe or disconnect the module and probe the connector. If there are not 12 volts then you have an opening in the TFI ingnition wire that needs to be traced. If there are 12 volts then you have either a TFI module failure or a stator sensor failure because you have ruled out everything else. I would just replace them both because diagnosing one or the other can get rather tedious and difficult.
If the preliminary test indicates that there is a lack of fuel, then think back to wether or not you heard the fuel pump run. If so, then hook up a fuel pressure gauge and cycle the key on-off-on-off. You should get about 35 - 40 psi. If fuel pump activation is confirmed but fuel pressure readings are inadaquate, then it's time to drop the fuel tank. Once the fuel pump is removed, check the small hose that connects the pump to the feed line for a leak or rupture since that alone could cause a low fuel pressure problem. If it’s OK, replace the pump.
If you have good fuel pressure, then the no fuel condition is an injectors not opening problem. Each injector should have 12 volts with the key on. To take this measurement you will need to probe one of the two pins (usually a red wire) at the connector and a good ground (chassis ground or whatever). If there are not 12 volts then you have an opening that needs to be traced. If there are 12 volts, then hook up noid lights to the injectors and rotate the distributor back and forth (key in the on position by the way). The fuel pump should prime and the lights should blink at you. If it does blink, then the injectors are not opening yet all the wiring is good and the computer is good; this means the injectors need to be replaced. If the noid lights do not blink, then you need to perform a wire continuity test between the injector pulse signal wire and the EEC. If this wire were open, you would still get the 12 volts, but the injector would not get fired. If there is no opening or shorting of the pulse signal wire then the only thing left is the EEC itself. The EEC would need to be replaced.
If the fuel pump is not running, then locate the fuel pump relay. Make sure it clicks when the key gets turned on. If it does click, then the fuel pump output wire needs to be tested. Use a test light...if it lights up at the relay with the key on, then you need to look for an opening between the relay and pump. If it does not light up, then you need trace the always hot wire. If that wire has voltage, then rplace the relay. If it does not have voltage, then look for an opening in that wire or an open fuse link. If the relay does not click, then you replace the relay and it still does not click, then you have and opening between the ignition switch and the relay. At this point it's just a matter of finding the wire that sends voltage to the relay from the ignition switch and repairing the connection. If all is good with the relay, the wiring from the ignition switch to the relay, the wiring from the relay to the fuel pump, the constant 12 volt source to the relay and the fuel pump does not prime, then it's time to replace the fuel pump. If it still does not prime, then the only other thing that could cause the pumps to not run would be the EEC itself.
If the problem does not seem to be fuel or spark related, then a compression test is in order. Mind you, a no start condition due to low cylinder compression is usually caused by operating the motor for long periods of time with an overheating condition. A fialure in 1 or 2 cylinders will not cause a no start problem. If the no spark and no fuel test results are passed, you would need to perform a cylinder compression test and / or a cylinder leakdown test.
