No fuel spray from injectos

Check fuel line for pressure - there should be something like a bike tire valve on fuel line - press the inner part of it and see if gas spurts out hard. If so you have pressure , a working fuel pump, and gas is reaching the injectors.

Check out the igniter?

That means bad injectors, or defective fuel pump, you probably need to replace the fuel pump.

They are clogged up ,need cleaning.

You would put on a new crank sensor because the ignition system won't work, it gives no spark. So now do you have spark at a spark plug wire end? A blue consistent spark? Probably good ignition system, as long as all spark plugs get a spark.

One thing you always want to check with no start is the fuel pressure. Turning the key to on should turn the fuel pump on and put pressure in the fuel rail at the engine. Autozone and maybe others rent or loan fuel pressure gauges. Multi-port injection systems have high pressure specifications, around 40 psi normally. That is what the injectors require to spray out fuel when they pulse and open the nozzles.

With the injector circuit, the first thing to check is if each injector has power to it with the key in ON. One power wire and one ground wire goes to each injector. The power wire is from a fuse that is powered with key on or key in start, and then it is spliced to all of the injectors. The injector grounds all run into the engine computer, where the circuit can be internally grounded for a split second and cause the injector to pulse. But anytime the key is on, the injectors have steady voltage available to them.

Hello Monica, that is a wide area to cover ,so you can go to auto zone site and log in (its all free) go to (my vehicle)in put info then go to (repair guide) then to sub catagorys there are a few including trouble shooting. check pressure regulater and or vacuum supply to it as well, you should have a test port next to it or near, test it with a pressure gauge to see ,pressure should be 35+ pounds . i really hope this helps you ,if it does please let me know
Woody

Check all engine grounds as the ECU relies on the control unit to find a ground and pulse the injectors. Also check the crankshaft sensor to make sure its pulsing when rotated. It should produce a 5 volt reference as it moves. Also check that you have fuel pressure as the pump also relies on a good ground to power up. Everything is controlled from the ECU.

Are you sure it's not the fuel pump? I would be checking fuel pressure-the injectors need fuel under high pressure against them so they will spray out when pulsed.
What year is your Isuzu, and what size engine? Multiport injection has a higher pressure requirement than throttle body injection.
There should be a fuse for the injectors, check that. With key on, not start, the injectors would have power to them on the "injector drive circuit". In other words, constant power is supplied to the injectors when the key is on. The other wire at an injector is the ground wire. The ground wire goes into the engine computer. When the computer internally grounds the injector wire for a split second, the injector is energized and fuel is able to spray out.
Post back if you need help checking the injector circuit-both the power side and the ground side. You can check both with a test light.

Well, here it is anyway: ground a test light and probe the injector connector. With key on, one terminal should be hot-the drive circuit. Now move the test light lead to the POSITIVE battery post, and stick the test light probe into the injector terminal that did not light the test light-the ground terminal. Now have someone crank the engine over. If ground circuit is working, the test light should be blinking-meaning the computer is properly grounding the injector circuit. If both tests are good-a steady light on the power side (key on) and a blinking light on the ground side (engine cranking), the injector circuit is good.

how much fuel pressure do you have you should have 50 to 60 psi

Check ignition and gas.

Listen for the fuel pump to come on for a couple of seconds with key ON. If you hear it, pump is working, check for gas at the fuel rail on top of engine. Should have gas under pressure.
If pump doesn't come on, check the fuel pump fuse, check fuel pump relay. Last, use a test light or voltmeter and check if the fuel pump wire has power to the gas tank connector when the engine is cranked over. If power there, fuel pump will need taken out and replaced. If no power at the pump, pump circuit needs checked.

Check ignition by checking for spark at a plug wire end. Pull off plug wire from spark plug, push the boot back so metal end terminal is exposed. Hold the end terminal 1/4 inch from a grounding source like a metal bracket or bolt on engine. Have a helper crank the engine over and watch for a spark-you need to see a blue snapping spark to know the ignition is good. Maybe wear gloves or use a heavy rag holding the wire-you can get shocked if not held close to a ground. Another way is to pull off the wire from plug, remove plug from engine, then re-attach plug to plug wire, and lay the plug on top of engine where the plug threads are touching metal-now the plug is grounded. You will not have to hold the wire. Have the helper crank the engine, while you watch for spark at the spark plug end. If you have a blue snapping spark, ignition is good. It is a good idea to check for spark on more than one plug wire-maybe another coil is not firing.
If your ignition is good, and you hear the pump come on, possibly a weak pump not putting out enough pressure- then check fuel pressure with a fuel pressure gauge. Fuel injection requires high pressure, so the injectors will spray fuel out.
If still no go, scan computer for trouble codes. Check if your security or theft deterrent has immobilized the car.
Good luck.

Check the injector for 12v on one wire. if good check the other wire for a ground witth the key on. The ground wire pulses from the ECM If you dont have 12v from one wire to the other but you have 12v from one wire to battery ground then be sure the ground wire is good to the computer. If you don't have 12 v at any time check for open hot wire or bad fuse. ADD 12v to the hot wire at the injector. DO NOT add to the wrong wire or you will fry the computer