"oil leak only" between heads on block makes sense to me. I have to believe if this area was prone to serious vacuum leaks FelPro would provide a quality gasket in the kit for these ends. However yesterday, I had 2 people stating their case to me on why this void in the bead at the rear of the intake would cause a problem. Im not a mechanic by trade but I have been installing aluminum intakes on cast iron small & big block Chevy's since the early 80's when I was a teenager. I can honestly say I do not remember a single instance of changing intake manifolds creating a serious problem and I was taught from day one to discard the end gaskets provided and buy a tube of high temp silicone while picking up the new gasket set.
With all that explained, I did go buy a new gasket set, took a lot of extra caution to make sure the lower intake was sealed properly this time. I did let the silicone set a little less than 15 minutes to skin over and when I set the intake on top of the motor I made sure to set it right over the bolt holes so it did NOT move at all when secured in place. I am very confident this morning the lower intake is sealed and installed properly.
My concern yesterday was the spider was not sealed to the upper intake properly and I really had my mind set that the upper intake needed to be torn back down. Before re-assembly of the upper intake I wanted to make sure I got "BF" advice on how to assemble it properly. thanks to you guys for sticking with me the past few days I now have that
information and will be able to post the results later today.
My gut is telling me after today's fuel pressure test that's where we're going to end up with the problem. I have seen in this forum preached constantly to start with the infamous fuel pressure test, it seems to answer a lot of questions and end up leading to
solving the problems associated with these fuel systems.
I have learned a couple things over the past few weeks: 1) I should have found a mild a 5.7 Vortec and 2) you guys that have been helping me know what you're talking about
I will bring more updates and more questions later this afternoon

 

The fuel pressure and leakdown test will only tell you if the problem is in the fuel system. To rule out the pump you need to modify the guage and dead head it before the fuel filter. There is a write up here somewhere, I'm on the mobile or I would find it for you lol. You can ususally just look at the upper intake and you can tell if you have a leak, spots will look really clean and gold. It should look really black and grimey. Be sure to post back your results!

 

The beads of RTV on the ends only seal oil, not vacuum, there is no vacuum below the lower intake manifold, only oil splashing around. Vacuum and coolant are sealed around each intake port and coolant passage with the metal frame & rubber intake gaskets. It's very possible the vacuum leak was where the plenum fits over the fuel metering block. The metering block must freely in the mounting bracket so it will self-align with the plenum. The O ring must be oiled before installing the plenum, so the plenum will slide all the way down over the O'ring without rolling it out of position.

 

Sorry been gone so long the shop closed Sun, Mon and Tues so I could not access truck, on top of everything else I need to keep my business going, customers are tired of hearing "I'm working on my truck" and a couple have suggested getting a new truck.

Scanner says "no codes", reset distributor 4x (it is set identical to link above), new gaskets in upper and lower intake. Turns over wants to start (sounds like timing is retarded) and it actually ran for 30-40 seconds, shut off and will not restart.

I have 3 mechanics and me all looking at each other without a clue. I'm very close to sticking a 350 with a carb in it

 

Make sure the outer ring of the dampener did not slip, (which is possible). When the timing marks on the dampener are correctly aligned with the marks on the timing cover, #1 piston is at TDC. The marks will line up when the cylinder is on the compression stroke and the exhaust stroke. Just because the marks are lined up correctly, is no guarantee that the cylinder is on the compression stroke. You need make sure #1 piston is at TDC on the compression stroke, (both valves completely closed) before installing the distributor. Very rare for the engine to start when it's out of phase, but it does happen, usually backfiring through the intake.

 

This morning engine starts and runs with spark plug wire #1 disconnected from distributor.if you connect spark plug wire#1 to the distributor cap With engine running it stops running. Will not start or run with #1 connected to distributor. Replaced distributor, cap & rotor.

What does this mean??

 

Are you 100% certain #1 was at TDC of the compression stroke when you installed the distributor? Sure sounds and acts like it's out of phase. When the plug wire is off #1, are all of the other cylinders contributing power? (try removing the plug wires one at a time to see if it causes the engine to idle rougher or stall, or has no affect. If it's out of phase, none of the cylinders will be firing at the correct time.

Another quick check: Is the cap wired correctly? Common mistake to transpose wires 1 & 3 on the cap.

 

The whole shop packed up and went to North Florida to do some trail riding and camping until next Wed so my dime is sitting in the shop until they get back. I won't be able to do anything until they open back up next week. I need to get 2 rental units ready for tenants anyway and I have spent so much time on this I'm falling behind

I purchased a rebuilt distributor from Advance this morning plus cap & rotor. I wasn't there to watch it go in but I can say Thursday afternoon I thought we got dead nuts on. I know we set TDC somewhere between 4-6 times while I was there Thursday. Every time it rolled over I could hear a burst of air out of the spark plug hole then I would turn crank with wrench to line up both marks properly. We moved it forward a tooth, backward a tooth and then put it in proper location still no start.

I don't know what changed this morning to get it to start but I was told on the phone when he asked me to send over a new distributor, cap and rotor "we have it running on 5 cylinders. If we leave #1 unplugged from the distributor it rolls over and fires with ease, if we plug #1 in distributor it won't fire and it rolls over with difficulty, if you start it and try to plug #1 in with it running it kills the engine and it won't start again"

One other issue: Maybe this is coincidence? I'm not sure but it should be noted the original engine that this one replaced also would not fire #1 and was missing when pulled out. I was really hoping the new distributor was the answer.

My guys are thinking bent pushrod, bad rocker or something in the valve train.

Finally Capt, this might be a dumb question but I want to be crystal clear for my own piece of mind. When you say "timing out of phase", what exactly does that mean?

 

Also I just read this thread about a 2001 Blazer:

The missing spark mystery was solved after lots of hair-pulling and gnashing of teeth, and a little close inspection of electrical connectors. Turns out secondary voltage was missing at ignition module, which led to the crankshaft sensor. Car had been jacked up and that had somehow tweaked the wires into the connector at the crank sensor. New harness/connector and that problem was solved. Next issue was distributor was in wrong, despite our efforts to carefully follow EDI directions.

I'm guessing I need to do a close inspection of crankshaft sensor wires? and the harness underneath?

 

That's a fairly reliable method however, when the piston is going up, it will give a burst of air on both compression and exhaust strokes. It takes a little practice to know which stroke it's on by listening to the burst of air. The compression stroke is stronger than the exhaust stroke. Turning the crankshaft by hand, (with a breaker bar) you'll never be able to hear, or feel, the difference. Use the starter to rotate the crankshaft. That way you'll be able to hear the difference in the air bursts as the engine turns over. Then it's a matter of stopping the starter at the right time and lining up the marks by hand for the last few degrees of rotation. FYI: Always rotate the crankshaft in a clockwise direction, never counter clockwise. If you miss the marks, DON'T back up, rotate the crankshaft 2 revolutions clockwise and line them up. This keeps any slack in the timing chain on the passenger side of the engine, (where it is when the engine is running).



Two engines with the same mechanical problem??? ...doubtful. A valve train issue on one cylinder, whether a valve is stuck open or closed, is not going to cause the engine to stall by firing the plug. What I would check, being both engines had the same problem, is that the wiring on the cap is correct. Like I mentioned before, very common mistake and often overlooked.

No such thing as "dumb questions" this is how we learn things If the distributor is installed 180 degrees off, in other words, when #1 piston is at TDC of the exhaust stroke, the distributor is out of phase.

EDIT: If there's a problem with the crankshaft position sensor, or its wiring, it will set a DTC in memory. The chances of it affecting only one cylinder are astronomical, borderline impossible