So... Take out all the new parts except the one that fixed the fuel pressure. It should run.
Given the list, what fixed the fuel pressure?

Ignition module
Air temp sensor
Coolant temp sensor
Pip sensor
Ignition switch
computer

If it was the computer,(???) it may have a dysfunctional injector driver circuit???
What is a 'Pip sensor'? From what I thought, it was a function of the TFI(Thick Film Ignition) module. Profile Ignition Pickup?
tom

 

I believe there is some confusion.
The injectors were not pulsing to begin with. The fuel problem was side by side with injector problem.
What fixed the fuel delivery was a new fuel pump, filter, and relay connection.

The truck runs a little bit better now but the trouble is starting.

From what I remember, and if I'm wrong please correct me, during cranking the PIP sensor sees movement in the distributor and in turn fire the inejectors. The PIP should work when the Rpms are below 300 rpms while anything above is taken by the computer.

 

No, you're still not understanding how the system works.

The PIP module is in the distributor, it feeds a signal to the ICM, which fires the spark. The PIP signal then goes to the computer, which the computer uses to fire the injectors. No PIP signal = no injectors firing. If your PIP signal is weak, the injector operation will be erratic. The PIP is always used to fire the injectors.

 

I just replaced my PIP so unless it's a bad part I have no idea why it ain't firing.
I tested for continuity through the pip wire to the computer and I'm getting continuity.
I tested out the new ignition modular and everything checks out. ( I didn't check signal from pip as I don't have an oscilloscope)

If my pip signal is too weak to fire the injectors during cranking why do they fire after reaching higher rpms?

 

The PIP signal may be stronger once the engine is up to speed. However, I think you have a ground/power issue that is preventing the computer from operating while cranking.

As a sensor sanity check, you should be able to unplug just about every sensor and still have the engine start

 

From memory, the fuel pump is energized when the key is turned to ON, for about 5 seconds, give or take. That pressurizes the system.
The fuel pump, in theory, will not get energized again until the computer sees the PIP signal, (or SPOUT, my memory is old), bouncing along indicating that the engine is turning over(running!). The computer then will energize the fuel pump circuit to enable continuous pressure and flow.
If the throttle is moved to wide open -WOT- the computer will stop fuel flow(injectors) as is figures us dummy hu-manz flooded the engine(how? dunno..), if the engine rpms are at cranking speed.
If your TPS is off value, or the pressure leaks back down QUICKLY!!!, there may not be enough pressure or any at all, when you are cranking. WOT(open, or bad TPS), or no/low pressure will starve the injectors. Do they get a 'spritz' pulse from the computer or not? (use NOID light or high-impedance VOM to detect the 'ground' pulse) Is there sufficient pressure for them to function, or has it leaked off too quickly? Sometimes the multiple cycles of the key from OFF to ON(pause 3 seconds) to OFF may allow buildup of enough pressure in a leaky system to fire off the engine.
PIP and SPOUT are produced by the TFI module, to my knowledge. The injectors in an old engine are ganged, 3 pairs of two, I think, on a V6. The Vulcan had paired, and did not go SEFI - individual spritz for each cylinder - until past 1987, and I don't know when. The 2.9 or 2.8 didn't get ahead of the Vulcan, so these do not have a cam sensor. They 'assume' when to pulse injectors, timed and fixed, and brain fade.. the have to know they are at TDC for #1 cylinder, and the 'opposite' at the same time, so they spritz both, and time the other two spritzes without a cam sensor... just wait 120 degrees of rotation, and fire away...
tom

 

When I turn the key on, the fuel pump will prime for about 1-2 seconds and it builds 40 psi like it should. The pressure holds like its supposed to and the injectors do not leak. When I release the key from the start position the pump kicks on for repriming. I don't have the grounding pulses but I do have power to the injectors.

How do I go about testing the TPS? I recently installed a new one.

You are correct the injectors are paired in 2 sets of 3.

 

CALL OFF THE DOGS!!
The black/lt green wires coming from pins 40 and 60 were grounded to the starting solenoid. I took it off and actually grounded it and the truck fired up like no problem.

 

Didn't I tell you it was a power/ground problem pages ago?

 

Good find, fix, feedback & to hear all now seems well.

Yup the #40 & #60 pins were to go to ground through splice S107 as shown here http://www.revbase.com/BBBMotor/Wd/DownloadPdf?id=15542, so how did they end up being connected to the starter solenoid?

 

Yes you did Lead Head

When I got the truck I knew it was played with by someone with no auto expirence. I don't think he knew the difference from a hole I the ground LOL.

That being said, the after market radio stopped working the other day so I took it out and found the ground wasn't grounded. I figured there must be a bad ground that's not letting me start the truck so I followed every ground with my toner and I found one on the starter side of the starting solinoid. The sad part is the wire was spiced with a big yellow ring connector and it never dawned on me to look at it.

 

Way to hang in there on your trouble shoot & see it through to a successful ending.
Good call on the grounding problem Lead Head.