I thought I had it fixed this time. I ended up pulling the lower intake because I was dumb and dropped a socket in the intake and couldn't get it with a magnet. Anyway, that at least let me fix my leaky valve covers and test the rail. No leaks, and starting pressure is now about 55lbs for about a minute. Its been working fine for about a month now, but today, same thing, cranks, but wpn't start. This time, good fuel pressure, but spraying carb cleaner in the intake did nothing, so apparently I have an electrical problem as well. I don't think I'm getting spark. Plug wires and coil pack are new. PCM is getting power since its still running the fuel pump and all the dash lights come one. CEL goes off once the engine starts. I noticed the PCM power relay is really hot, which makes me think there's a short (not a dead short, but a short) somewhere. Any thoughts on where to look for the problem? It had just rained when the problem occured, so maybe water got in somewhere?

 

Seeing as how you intermittently don't seem to have spark & the PCM power relay seems excessively warm/hot, maybe put a B+ feed problem to the coil pack, or leaky, shorted ECM ground switching driver/s on your suspect list.

 

It rained last night, and the truck didn't want to start this morning. Same thing, the PCM power relay was warm to the touch. I measured B+ at the coil pack at a little over 12V. I also measured voltage at the PCM. It has 12V at all three coil pack connections. I know this wasn't under load, so I don't know how much that test really means. I also pulled the cables off the PCM and the coil pack at the same time. No leak to gound anywhere here. I didn't check this, but I'm thinking maybe I have a leak to the power rail instead. When a coil bank is fired, the PCM pulls the bank wire low to generate a pulse. Therefore, on the PCM side of the coil pack, the voltage should be somewhere in the 0.5-2V range when the coil pack is firing. If there is a leak to the B+ rail on this side, that would explain why the relay is warm only when trying to start, and doesn't heat up more as the truck sits. I'll try to check that tonight. I don't think this model has an ECM. I think it only has a PCM. The Haynes manual only shows connections to the PCM. Also, its a stick, so I don't have all transmission connections to deal with if that makes any difference.

 

When its acting out on a start & you think spark is going missing, use your inductive timing light on any spark plug wire to test for spark.
A battery resting/no load voltage "a little over 12 volts" suggests the battery soc is low, maybe it's down on charge from a leaky cell, or the alternator isn't doing its thing to keep the battery charge topped off. 12.06 resting volts = 50% soc.

 

Spec fuel pressure is 64+/-8, so your on the low side of spec for fuel pressure, technically 1 pound low & that's unexpected for a new fuel pump/regulator assy & fuel filter. Are you certain you don't have a voltage drop to the fuel pump????
Seeing as you have the ELM scantool, which is a very powerful diagnostic tool, plug that puppy in & see if it can spot something when its acting out on the intermittent start.

 

Disconnect the coil pack electrical connector & see if you have continuity to ground on the coil pack return leads to the computer. Then go to KOEO/run position but don't crank the engine & test from the connector B+ feed to each coil pack return lead to the computer to see if one of the computer drivers is leaky or shorted, or you have a return wire with an insulation problem to ground. You shouldn't have any continuity to ground, so you shouldn't be able to read B+ between the B+ feed & any ground return lead, unless one of the computer ground switching drivers is faulty, or one of the ground leads insulation is bad & you have a short to ground.
More thoughts for consideration, let us know what you find.

 

I used autozone injectors:
Price: $46.99
Part Number: 800-1591N
Warranty: 1 YR
Notes: 6 required

when I had a miss that we could not isolate. They have worked fine no issues at all.
They are GP Sorenson which oriellys also sells. One or other will price match or go lower by 5% I think.

As to hose, try a hose supply in the area. When I did my diesel coolant filter I got the hose from one of them and it was 3/4 but if its for the oil/evap system you will want a lined hose to use.

 

It did it again yesterday morning. It was humid, but bright and sunny, so I think the problem is getting worse. Unfortunately, I couldn't scan the computer since my computer was at home, and I was not. I had someone else there helping me. We pulled a plug and held it against the AC compressor, and nothing, so that confirms the no spark. I tried some of the measurements you mentioned and found nothing abnormal. I don't thin my meter was working right, though, so I am going to try again today. I make the trip home in less than a week, so I'm trying to avoid lifting the bed off (too much stuff already packed). I know my pressure's on the low end, but its at least enough. My alternator is new, and puts out about 14V when running. I think my voltage was low because I'd been cranking some before measuring, but I will check it again today. I'm thinking maybe a bad power supply wire now could affect the fuel pump and spark? but I don't see any corrosion or loose wires anywhere. I also still can't figure out what makes it start eventually. I even opened the computer yesterday to look for burn marks. It looks fine in there.

 

Ok, good trouble shooting feedback.
No spark suggests either no B+ to the coilpack when cranking the engine, or no ground switching of the coilpack by the computer ground switching drivers, or electrical breakdown in the coilpack. High humidity could cause this to happen if the coilpack were cracked, especially unseen underneath as they're known to do.
So, maybe unfasten raise the coilpack & have a close look underneath for cracks, or signs of carbon tracking/arcing. Maybe perform the wet down test with a spray bottle of water at night, looking for an arcs & sparks light show.
If no joy with that, check & clean the computer ground connections & the body to engine & battery ground connections & maybe swap the under hood power distribution box located computer power relay, for a known good like one, such as the AC power relay & see what happens.
EDIT: I didn't include a crank sensor problem because you haven't posted a trouble code for it, but they are known intermittent problem parts, so I suppose it at least belongs on your suspect list.