My car will only run if one injector is unplugged otherwise it only fires for a few seconds and shuts off

Called dieseling the engine runs because of unburnt fuel in the chamber. Sometimes caused by injector bleed down

Some model security systems shut down the injectors when activated. Is the security light on or flashing?

If by cranking you mean the engine starts then you are having fuel issues. If the car starts with starting fluid then you either don't have fuel pressure or the injectors are not opening. After starting with starting fluid does it continue to run until you shut it off or does it shut off on its own?

Either way you will need to install a fuel pressure gauge to make sure you have enough fuel pressure. If you do have fuel pressure then you will need to make sure the injectors are firing. There is a tool available called a noid light or injector pulse light. You will need to unplug one of the injectors and plug this tester into the connector. If the light flashes while cranking then the injector is being companded to fire. If the light does not flash then you either have a bad engine computer or a control module. More than likely it is the control module. The control module uses the input from the crankshaft position sensor to fire the coil and the injectors the module may be loosing the signal for the injector.

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Have you checked the Cam sensor? The Cam sensor controls the injector pulse.

Your fuel pump runs for a few seconds when you turn the ignition is turned on because the fuel pressure naturally eases off when the engine is stopped, it runs until it gets to>< 30PSI and kicks off. This is normal, you know that fuel is reaching the injector line. On some engines there is a solenoid that has to trigger before fuel can go into the fuel lines for the injectors. If this solenoid isn't firing the computer will detect it and shut off the ignition. Look for some kinda solenoid or gadget where your fuel line come up in front of the fire wall. It should be close to where the fuel line splits off to go to each bank. Hope it;s a wire come unplugged and easy fixed. dhgill1949

yes it can, i had a corvette with the # 6 fuel injector that was bad, it would start up, and run a few seconds , then die, wait a few minutes, crank it again, then sometimes , it wouldn't start, then i would wait a while and try it again, and it would fire up, and run a small amout of time , and then die, i checked the fuel injectors to see which one was not working, and found out that it was the # 6 injector.

Fuel pump won't run unless it starts, it is designed to run for two seconds then shut off, if it were to run and you had a damaged line you would cause a fire. The cam shaft sensor gives you spark and injector firing but the crank sensor has to work two, check to see if you pinched off the wires on the crank sensor, also does it have a coil pack? If it does leave me a post.

fuel filter could be the problem

Try the fuel injection relay they are located under the hood. They blow out every few years on my Volvo. The car starts to quit all of the sudden. It is either red or green colored. It is located in the fuse box under the hood.

Come to find out after spending $560.00 on electric parts that were not needed, the number 5 fuel injector was shorting out causing the engine not to start. It would turn over but wouldn't catch. I unplugged the injector and it started right up. I let it run for a bit and while running, plugged it back in and sure enough, the engine stalled. This particular engine had us going crazy. We thought if an injector went bad at least have the engine would run. Apparently this one has a safety mechanism on it so half the engine won't warp for working while the other half don't. The injector will be replaced very soon and will be back in perfect running condition.