I think the severity of the leaking injector(s) vary, which is why sometimes the engine starts on the first "timed" crank. Maybe during my pinch test it wasn't leaking as much as the last fuel pressure leak down test (which dropped 5PSI in 8 seconds). The first fuel pressure leak down test I only lost 5 PSI in two minutes. The leak doesn't seem consistent, which would also explain only occasional sporadic rev'ing while running. It definitely isn't a linear leak, though. I clamped it really well! haha

I see. Moving things is not an enjoyable process but selling them can feel so liberating. Let me know when you're settled in again.

 

Go with your injector leaking. You can check and verify the leaking one(s), and replace all.
Btw, I'm a tool hoarder. I bought my first tool back in the 70's. Now, I would need 2x 26ft moving trucks, just for my tools. Selling my tools is easier than moving them and they're selling fast. I will still keep enough tools to fill 1-26ft moving truck.
Anything, I need to do, I got the tool. Yet, I have 1-100 of the same tool.

 

Still in the process of this conversion, but I think it looks great so far!

My plan is to completely remove the head-unit and then install a hidden Bluetooth amplifier. The amp will act as the stereo controllable via Bluetooth (either on my phone or the tablet) for navigation and music. The tablet also will serve as my datalogging device, which also connects to my MPVI2 HPtuners dongle via Bluetooth. In the cavity left from the factory head-unit, I plan to create a power zone with two hidden wireless chargers so the phones can ride in there along with keys or whatever. This power zone will pretty much just be another glove box (possibly w/a door on it eventually). The air vents will also be re-routed to this "cavity" so the A/C and heat can still flow from the center area of the dash (I know heat would not be good for the phones in there). I'm super excited about this and can't wait until I have more time to get it all setup. Another cool benefit will be the ability to flash different "tunes" on the fly. I can have a tune for economy/commuting on it most of the time and then switch to a more performance oriented tune when I am in the mountains or off-roading. I bought the tablet for cheap off FB marketplace and it fits this spot perfectly.

 

Update:

Pulled fuel rail off with injectors. Primed fuel pressure to inspect for leaks and found none. Drained fuel pressure and checked again, still no leaks.

I checked each injector for resistance with the following readings:
#1: 12.2-12.4 (12.4)
#2: 12.2-12.4 (12.4)
#3: 12.3-12.5 (12.5)
#4: 12.3-12.4 (12.4)
#5: 12.2-12.7 (12.5)
Some of the readings jumped around a lot before settling on a (value). Their (values) are all very similar, which leads me to believe the resistance of each injector is within spec.



Also, my intake valves are gorgeously clean.



Hummerz, my pinch on the fuel line may not have been good enough and the pressure could have been leaking from the fuel rail side back into the supply line on the tank side. The leak could be my fuel pump assembly causing the loss of pressure, unless leaking injector(s) have temporarily ceased (which would be consistent with the occasions when the vehicle starts immediately on the first "timed" crank). I am still uncertain! I will keep occasionally pressure cycling to see if a leak starts ever. You sent me the chart of AFR's for different scenarios. I am wondering if the issue is related to cranking AFR. Maybe during the "timed" crank sequence, their is a different AFR than the second "manual" crank.

When I install the new injectors, I will be updating some airflow and fuel tables from the 2006 3.5L to the 2008 3.7L values. These will impact the air and fuel during the crank mode (cranking volumetric efficiency, injector flow rates, & cranking fuel). The '06 injectors are 28 lb/hr and the '08 injectors are 32 lb/hr.

 

You took the long route to verify leak down. Now go back to the tank and replace the check valve, or replace the FPM.

 

I sure did, but I think it'll be worth it in the end. Where/what is the check valve? I will order a new fuel pressure control module assembly (fuel pump), probably.

 

I've made a lot of progress towards virtually everything but the starting issue.

I upgraded the factory fuel injector harness from the original Multech 2 (mini-delphi) connectors to USCAR (EV6) connectors in order to swap from early LS truck (original) injectors to late LS truck injectors (2008+ H3's). The harness turned out really well and the injectors fit properly. If anyone in the future pursues this injector upgrade, beware doing so requires PCM adjustments (I am using a stock 2008 H3 file to copy/paste the newer injector tables in HPTuners).




With the intake off, I cleaned the intake ports with carb cleaner and a couple of clean rags. There was a tremendous amount of carbon build up on the ports, though the valves were spotless.




I replaced the intake manifold gaskets as well as the throttle body gasket. The previous owner had removed the A/C system, and I have re-installed it along with re-wiring the A/C compressor harness due to it being sheared off. I bought a Denso A/C compressor from a 2011 Colorado with 140,000 miles. I figure $35 (used) vs $350 (new) is worth the potentially reduced life of the compressor.

While so deep in the engine bay, I re-routed many wire bundles to their appropriate areas with new clips and also installed some brackets I found on a Colorado at the junkyard (engine lift bracket & intake manifold bracket).

I have made good progress towards my e-fan swap (using a Ford Taurus e-fan, Volve relay, & BMW thermoswitch). I have the thermo-switch mounted at the upper radiator hose to trigger sooner than the bottom hose and also wired the high-speed side of the relay to switch on while the A/C compressor is engaged. This will help the A/C run cooler.



Lastly, I flushed the engine cooling system 15 times with distilled water. Prior, the reservoir was filled with what looked like a combo (blue, orange, and yellow) and the radiator was yellow'ish brown. With a ridiculous amount of distilled water, I was able to bring the whole system to solely distilled water before finally filling with 50/50 Dexcool.



(My catch can had a bit of oil residue in it, which is why there are speckles in the jugs).

 

I got everything put back together and adjusted some more tables in HPTuners to compensate for the larger injectors. The engine starts and runs as usual (still has the starting issue as expected, since the injectors were not the issue).

I drove around to datalog a little bit and look at long-term and short-term fuel trims (LTFT & STFT). The fuel trims at idle are near zero. Under load/acceleration the total fuel trim approaches +25% at times, which leads me to believe either a dirty/bad MAF sensor or an issue with the fuel pump assembly. Since I have cleaned and replaced the MAF sensor, I am ruling this option out. Datalogging just adds support towards the fuel pump assembly hunch.

 

I picked up a used Denso A/C compressor from a local pick-a-part. A friend with an A/C charging system back in MN really convinced me of their value (as compared to A/C manifold gauges), so I brought my H3 into a franchise to have them charge it with their machine. After I sat in the grass for over an hour, the technician came over and told me it was fully charged but was not blowing cold. He suggested I take it to a local shop to have my A/C system diagnosed.

So, I hopped in and kept the A/C on blast on my ride home. I kept my hand on the vent and every once in a while felt a cool burst. I left it parked in the garage and went out the next morning to test the A/C again. I used a hygrometer/thermometer in the vent to check it and found it was blowing 47°F! I referenced the HVAC manual and found this was the proper "lowest" temp on the chart. When I bought this H3, the A/C hard lines and condenser had been removed, leaving open inlets on the compressor and expansion valve. I had to replace the compressor because it had froze from being left with open inlets exposed. I bet the expansion valve had also corroded (especially with my engine bay cleaning episode). I imagine the refrigerant/oil slowly worked out the corrosion in the expansion valve, allowing for proper functioning of the A/C system.

 

might be free to you but someones time and product went into that. i am sure they eat to survive.