No power to injectors 350 tbi

What have you checked? I would start with a noid light to see when the two injectors wiring is pulsing. if intermittent then i would check the pickup coil located inside the distributor. It controls timing for the injectors and for the timing advance.

You need the computer and the harness or you have a ground issue test for injector pulse with a noid light

First understand how the fuel injector circuit works that causes them to spray fuel out, then you could probably find the problem. It's really simple, the key thing is that the hot wire to the injector (there are only two, a power wire and a ground wire) is always hot anytime the ignition key is in on, or run, or start. It is a fused circuit that is powered on when the key is on. The fuse is either in the distribution box under the hood or in the instrument panel fuse block.

The ground wire from the injector goes into the computer where it can be internally grounded inside the pcm for a split second. This is what causes the "pulse" of the injector, a needle is raised electromagnetically, and fuel under pressure is sprayed out. The computer can vary the pulse width, by duration of ground time, and really fine tune the gas metering.

Check for power at the injector connector with key on. If nothing, check the injectors fuse, and trace it back to the ignition switch. If there is power on the hot wire, one way to further test the circuit is to go buy a cheap "noid light," a tester at any parts store-different sizes, but easy to find a standard for gm vehicles. A noid light checks power and ground wires at the same time. Now that you understand "pulse", a noid will blink as if it were being pulsed-well it is, just that. Hook it up to an injector connector, and the engine has to be cranking over-that is when the computer is grounding the circuit repeatedly-when the engine is running and when it is cranking by the starter. If the noid light blinks, the circuit is working correctly. If the light doesn't turn on at all, first verify that the power wire has power with key on. If it does, problem may be in the ground side of the circuit, or in the pcm itself.

So, it's the injector circuit. There is a 10 amp injector fuse in the fuse block, on left side, 4th one down. Check this fuse. It supplies constant power to both injectors, on the red wire to injector 1, and a white wire splice from this to injector 2. A steady 12 volts anytime key is in on, run, or start. You can check this with a test light or voltmeter. Ground the test light and probe injector connector's red wire on injector 1, and the white wire on injector 2-both should be hot with key on.
This may be why the noid light didn't blink. The noid light must have this steady power signal, and when the computer internally grounds the injector ground circuit for a split second, you get injector pulse-or a blinking noid light.
You can check the ground circuit separately with a test light also for each injector. Place the ground clip of test light on the POSITIVE battery post, and probe the blue (ground) wire on injector 1, the engine must be cranking over, and the test light should be blinking. Do the same for the green wire on injector 2. If the test light is blinking on both ground wires, with engine cranking-the ground circuit is good. You are sending power down the ground wire to computer, and when the computer grounds the circuit, the tester will light up-it will blink because the computer only momentarily grounds the circuit to cause pulsing of the injectors.

Are you certain that the pump is on when the no start occurs? Do you hear it turn on with key on, not start, when the engine won't fire? It should turn on for 2 seconds to pressurize the line to the injectors. If you could, check fuel pressure when the no start occurs.

If it is the injectors, buy a cheap "noid light" to check the injector circuit. Buy the one that fits your injector harness connectors. You pull off a connector to one injector and put the noid light in the connector. When cranking the engine over the noid light should be blinking-that is the pulse that fires the injectors. The injectors have battery voltage to them any time the key is on. When the ecm momentarily grounds the injector circuit (internally in the ecm), the injector is pulsed. If the noid light does not blink or even light up when cranking, the injector circuit has a problem in the power side or the ground side.

The injector ground circuit must not be working. What causes the pulse is when the computer internally grounds the injector circuit, power is passed across the injector solenoid terminals. All the injector grounds are spliced together on each bank of engine, and run into the computer. So, injector power, but no pulsing would seem a computer malfunction as long as the ground wires are good. Did you check all the injectors for pulse with the noid light, or at least both sides of engine?

A number of possible problems unfortunately. The most common problem would be the ignition module.

this could be a bad ingnition module or a loose wire. but i think on this truck the injectors do get singnal from the ecm

Check the fuel injector ground circuit from the ECM

Have you checked for injector pulse with a noid light at the injector connector? You could have a bad ecm.