I concur with using not any starting fluids. Seen too many damaged motors in the past. Last resort only and use very little.
Generally if the compression is good enough to blow your finger off the hole and there are equal pulses the motor isn't the issue.
It's then down to fuel or fire,
-Fouled plugs are usually one of the most common things, even if they were brand new NGKS. I use known dead plugs to plug motor after assembly, during install. Take them out to do initial spin to blow out assembly goo and get oil circulating.
Fuel is disabled.
Then enable fuel and install good plugs. If it doesn't fire within 5 secs of cranking, something isn't right. If it was running fine when it came in or fine before it popped then I know I missed something putting it back in. On the few that didn't light right away it was usually electrical or vacuum related, electrical connector not connected, blown fuse, 2 had broken wires under the insulation, or vac line not on or cracked hose.

Back to your issue,
Put a known good stock box back in it, you just want to get it to start and go through some breakin. Better to run rich then, when you think of it. Just want to make sure it idles and doesn't have any leaks.
Disable fuel and clean it out well.
Make sure it is spinning over 200rpm higher the better.
quick check plug fire, plugs in wire out of motor against chassis, Of course - Don't hold them please. If you are getting a good blue white spark, install plugs. Enable fuel and try.
If it doesn't show anything in 5 to 10 secs. Pull the T plugs, check for fuel if dry, why? If wet pull L's, clean.
Disable fuel, clean out motor. Enable fuel, use something to clamp off the fuel supply hose. Small needle nose vise grips with pieces of fuel line on the jaws works really well. Install plugs, spin for any reaction. Sometimes they try to light.
With key on open and close vise grips.
Try again. If it lights then dies then open up the grips just enough to let a little fuel through. Might take a few trys to get it right. But when you do the thing will usually fire and idle.
After it runs 10 20 secs , slowly open the grips.
With that proceedure I can usually get the problematic flooded FC to run in 10/15 min.
If there is a hidden wire issue that is another thing.

Swap the proper size primaries in and go from there.

Were the plugs wet/dry?
Did you check for good spark at the plugs with them on a good ground?

I'll have to agree that the 10" of vac while running seems very low. There's alot of possibilities as to why that would be, but the most likely is a vac leak...

I still say to check it over, and then bump start it (check over should include fitting proper primairies :) ). That way you'll at least be able get it running, assess vac leaks and get it up to temp to seat the seals a bit. If its got spark, and fuel and timed right - it WILL START EVERYTIME with a bump start, it can't NOT start unless something is broke.

well, worked a little on it today. Checked a lot of things out.

First up vac leaks:
I've checked everything, new gaskets, new intake caps, etc. No way is it leaking in enough to keep it from starting.

Fuel:
I've done everything to check to ensure that I'm getting fuel in the engine except pulling the primary and putting voltage to it to see the spray pattern. Checked resistance, checked major components along the path, checked main relay. They all check in spec. While cranking I heard the high pitched tap of the injector firing as well. By all means, I should be getting fuel dumped into the engine.

Spark:
When I pulled the leading plugs I noticed they were wet, not a super flood, but enough to ensure that the spark plugs are getting fuel to ignite--at least I think they are. I didn't really focus on the spark to ensure that I have good blue spark or not, I'll check that next time I head out.

ECU:
I hooked up a stock ECU and still had the same trouble. No desire to start up.

When I came into the garage today, it actually started right up without issue, and attempted to stay started for a few seconds before puttering out.

I'm still scratching my head on this one. I may attempt to turn down the fuel pressure to around 10psi and crank it. If it still doesn't attempt to crank over, i'm not too sure what's wrong.

The plugs themselves don't look fouled, infact they look almost brand new. Can't really figure it out. It's behaving like there's no fuel in the engine, but the plugs get wet.

I've dropped in two cap fulls of 20w50 oil into the combustion chamber, but still doesn't want to turn over. Should I move to a lighter fluid (10w, 5w, etc)?

any other suggestions or comments for me to check?

Does the Rtek show you a value for the coolant sensor? Wondering if its not applying enough correction for a coldstart.

How long has the total run time been now?

it does. It reads the value just as it does for stock. I did notice however that it's reading it as a hot start or that the coolant is above a certain temperature... but that might be because I forgot to hook up a specific sensor. I'll double check that today as well.
maybe... 20-30 seconds give or take.

I keep coming back to a fueling issue, but I just don't see how that is possible especially. The injectors were cleaned and flow tested. I believe I heard the high-pitched tap of their operation while cranking. They have the right size in there and are trimmed to be 460cc/min during operation and starting. I have fuel pressure.

Which leads me back to spark... but the engine kicks on for a second or two on the vapors of the starter fluid, not the actual fluid getting into the combustion chamber. I'm planning on pulling the plugs today and testing for spark on all four. see how it works out.

Still haven't gotten my compression tester back from the guy I lent it too, so I can't give accurate numbers, but I have reason to suspect that the map reading is actually low. While just cranking, not actually starting, the engine produced enough vacuum to surprise me how much air it sucks in while cranking (enough to create a big force to pull my hand away while it was cranking--feels much more than 10inHg, almost like a shop vac)

My problem has to be with one of those 3, otherwise it would be starting and running. Sigh, is there any "easy" way to see if the injectors are putting fuel into the engine?

If your plugs are wet and smell of fuel, they are getting fuel into the motor. How much or how little has yet to be determined.

We can go round and round but we NEED to start crossing things off the list.

First, I would make sure there are no electrical issues with the Rtek. I would double check everything electrical, sensors, injectors, etc etc etc. Make sure everything is square biscuits there.

After that I would make sure the timing is set correctly and there are no ignition comps advancing or retarding the timing. I set my timing and then tried to double check it once it first fired @ 5* ATDC and she almost immediately stalhed. Make sure the timing is firing ~ 0-5* BTDC while cranking. While dicking with the ignition system I would make certain that all the plugs are firing and that they are firing in the proper order.

Lastly, compression. If the motor is pysically incapable of running becuase of poor compression, all the horsing with the fuel system in the world won't make her run.

Basically I would make sure it can't be anything but the fuel system before messing around and trying to touble shoot it.

Anecdote - I had a 40 horse Merc that was running like crap. Usually it's the carbs. So I rebuilt the carb, cleaned it out and then reset everything to factory spec. The carb wasn't that dirty, but it wasn't clean. Thing still ran not very good.... interesting. So I checked the plugs. Fouled, but not horribly fouled. So I replaced them. Still not running the way she should. Now I'm getting pissed. Compression? Check that and it's great. Start troubleshooting some more and find that the spark is weak. Traced it back to corrosion inside the harness not giving the coils full volts. Had to replace the whole harness but she ran like a top. Actually just started the thing today for the first time this season. Not my boat BTW. Moral is, sometimes it's a bunch of little things adding up to make one big problem. So I would make certain that it's not a few little things - spark, compression, fuel - by checking that the ignition system and compression are tops before looking deeper into the fuel system

Well, I think I isolated what the problem is. For whatever reason the injectors are not energizing. I've checked the main relay, the resistor pack, and the CAS. They are all in spec. I didn't have any procedures on how to check the individual circuits created while cranking, so I made do with a multimeter and trying to at least measure some voltage from the injectors. I would imagine that at least 2.5-5v would be applied for a brief period of time to the injectors. No luck. Didn't read anything. Tried it with both a stock ECU and the RTEk. No go.

So here's the problem:

Fuel is not being delivered to the engine, and what I was thinking was fuel was a fine film of oil. The spark is great, as is the compression (anecdotal evidence being a few cc's of fuel dropped into the manifold while I was removing the intake, when I was attempting to check the injectors the engine started right up from that little fuel that dropped in).

So the problem is electrical and occurs between the main relay and the ecu. Injectors are good, cleaned, flow tested, and ohm checked. I tried to check continuity between Black-Yellow on the connection to the main relay, and Black-Yellow on the resistor pack but read 0 continuity. So here's where I need help. How do I start checking what's wrong and what connections need to be made? I'll be looking over the FSM and trying to track down procedures for ensuring that the proper circuits are engaged. I'll also be posting in the RTek forum concerning trouble shooting of energizing the injectors.

So there you go! We've got the problem narrowed down to exactly what it is. No fuel because the injectors are not energizing.

You should always get 12v to the injectors when ignition is on, ecu grounds the injectors to open them, if it's an 87/86 check the resistor pack as well it may be bad or disconnected it's around where the airbox is. Otherwise i'd say you probably have a bad fuse or your wiring harness is fucked. Also, NA or T2, what year exactly?

87, na.

Doesn't the Rtek have some way to remove the resistor pack? Or could it be that the injectors are not Ohm'ed correct for the resistor pack?

He should still be getting 12V though even if theyre the wrong injectors, unless maybe the test wasn't done correct?

12v+ he should be getting to one terminal. The other should be open. It should latch to grnd to complete the circuit and open the injector. So if he's testing across the two terminals in the injector clip, than yes, that would be wrong.

How the resistor pack plays into all of this I do not know without seeing a schematic. I I would imagine though that all it does is alter the resistance that the ECU sees of the injectors. I know that I would want to get rid of it though.... one more failure etc etc etc. If the resistor pack is fine and there is still no voltage to one of the wires while the key is on, I would start looking up the line allllllllllll the way back to the battery. That's really the only way to trouble shoot shit like this. Start at the end, and work your way back. Testing every connection on both sides of the connector until you find the one connection, or stretch of wire between the connection that has lost continuity.

Yeah, make sure your ground is the chassis or battery when testing for voltage at the injector plugs.

Got it to start and hold idle like a champ. Problem was a plug that looked as though it was all the way pushed in and making contact was not. The 12v reading was not being read to the injectors from the main relay because that plug was not plugged in. I've plugged it in and did a run on it, idle was perfect at 1000rpm (set a little high for break in).

I saw EGT's of 900-950 F WBO2 readings of 13.2-13.7 and vacuum at 20inHg, with a peak at 30inHg when I was still trying to dial in the idle.

That is good news - i totally missed your problem and came back online in time for the solution :)

Good job on the rebuild man..