Den- So you think that the sensor may be bad? I went back and adjusted my settings to get the whole signal to fit on the screen and it straightened out in to a perfect signal. I think maybe I was somehow amplifying some ground noise (I have a 3000w sound system) or something. I don't really know what I'm talking about when it comes to that stuff so I might be wrong.. I haven't gotten to the point of disconnecting it, since it's kind of hard to access without removing the intake manifold. As for the air leak, one of the first things I did on this overhaul was removing the intake manifold and replacing the knock sensors and harness. I also cleaned it up extremely well except for inside the actual ports where the hard, crusty carbon is. I wasn't sure if it would be bad if any of it went in to the cylinders. I had a shop vac hose shoved in each port as I cleaned around them, though. As far as I could see, the intake valves were very shiny and didn't seem to have any carbon. I had just run some Seafoam through the engine, so maybe that's why. Seems like those detergents would remove deposits from hard metals like whatever the valves are made of compared to the iron block, which seems very rough and porous especially in the ports. Is this some type of acid erosion caused by old oil? I don't think the previous owner kept up on oil changes at all. They had also used silicon sealant to try to seal the manifold leak. Apparently silicon is a no-no anywhere near the path to the O2 sensors, as is Seafoam. I have since replaced both upstreams and I torched off the residue from the best functioning remainig old O2s and used them behind the cats. All O2 voltages seem normal, but not fluctuating 3x per second as they should be. I see maybe .3v-.8v-.3v and so on once per second. It may just be my cheap Chinese wifi code reader though.
I have sprayed all possible vacuum leak areas with carb cleaner, propane, and water with no results. I even removed the evap solenoid and plugged that with my finger to rule that whole system out (not sure if I'm correct in how I tested that, but it made sense at the time). I believe it sounds like a diesel because I may have a leaky injector that I discovered tonight and that is probably thinning out my oil, which sometimes is only at 20psi at idle, when a couple months ago it was always at 40. I can only hit 40 at WOT now when I used to get 80psi. I need to put in some Mobile 1 synthetic and a nice Fram filter, since the last time I changed the oil I skipped the filter because I didn't have the proper tools to get it off (my idiot mechanic over-tightened it). I'm probably gonna order a special tool or just jam a screwdriver through the side and twist it off. I also have ramps that will make the job much easier and it's finally getting warm out. The timing chain in these vehicles is very short, so the "stretch" would be minimal because of the small number of links there are to wear out. Plus I think I have variable valve timing, so doesn't it rule that out in a way? At idle, I get +18 spark advance and up to +50 at WOT.
Checked the exhaust as best as I could for leaks and it seemed good. No hissing from the cats or muffler either. Still a large amount of water coming out of the exhaust though. A very unusually large amount... I have not checked the injector spray pattern, but tonight I tested out the flow rate. I thought my method was creative, but it almost ended badly. To get a consistent pulse, I wired an injector plug to one of my turn signal lamps and hooked up my fuel pressure gauge and primed the system to 44psi (4psi below spec...I just realized this). After priming to the same value on each injector, I turned the turn signal on for one full pulse and read the pressure gauge and all injectors ended at 5-6psi. One injector, however, began to leak pressure as soon as I hooked it up. I did not pulse it, but just hooking up the harness somehow made it open and stick a little bit. Pulsing it a few times made the leak go away so I could resume testing. I'm sure you've already guessed that what I meant by almost ended badly, is I hydrolocked my number 1 cylinder because before I started the test, I did not realize that the turn signal lamps were constantly on with key on, engine off while the automatic headlights were on. There is now way to prevent the turn signal from coming on when the key is turned on to prime the pump, so I left the key on and turned the light off with the switch and primed the pump manually through the relay socket with a paperclip. I used pins 30 and 87 to do this, I believe. Bottom left hole and top right relay hole. I probably primed the pump 10 times before I realized what was happening each time I used the key. I didn't think the fuel would sit in there that long, but looking back, I should have known. I only attempted to start it twice before coming to the hydrolock conclusion. The engine did not fire, so no damage was done, but it did make a scary "clunk". I pulled the spark plugs and was met with a large amount of fuel only from cylinder one. I then used a big crescent wrench to hand crank the engine and get the rest of the fuel out. Engine fired right up, but the weird thing is, after driving to the store and back, my fuel trims are now down to +7%. It seems to change from day to day. Most days seems to be 15% or so. It's never gradual and seems to change instantaneously at startup or something. I never see the change happening. Lastly, I'm not too sure on the load, but I think it comes from the MAF and crank sensor (RPM) readings. I've also read that the TPS and MAP may play a part, but I know the curve on a graph very closely follows the MAF rate and volumetric efficiency. I don't have sources to prove this, but I've read that your air flow rate should equal 80% of the factory spec horsepower. Mine is rated at 295hp, so I should be getting 236 g/s air flow at WOT and I can only get up to around 185g/s. Remember that the MAF is a refurbished Delphi and I tested it and it's within spec at idle and the digital signal changes smoothly without glitches. Something is basically stealing efficiency and not allowing the engine to pull in more air simply because it's not able to pump it in. If my piston rings are worn, which they most likely are, I think putting in a higher quality oil to replace the fuel contaminated oil that is in there. This should in theory fix the oil pressure and give me much better compression. I need to fix the injector leak first though. I hate to admit this, but I put in about 1/4 bottle of Seafoam in the oil, but didn't realize you do that BEFORE your oil change and not after.
PCHi-I have not gotten around to a compression test yet, but I did rig up a tester that I could only fit in 2 spark plug holes and it only went to 100 psi without adding oil, but on the 2 cylinders I was able to test, I got well over 100 on the first crank. Since fuel trims are even on both banks and both cylinders I tested were on the same bank, I think my compression is probably withing spec, but may be suffering due to the thinned oil/oil pressure issue that I probably created and made much worse tonight after the hydrolock. The oil will probably continue to get thinner at an exponential rate, due to acidity and oxidation taking hold.
Gregg-I had no idea that the lifters required oil pressure to be pumped up, but the AllData manual says the spec is 6psi at 1000rpm, which doesn't seem right, especially when the norm seems to be 40psi at idle. Everything does seem to point to thinned oil, which could be mimicking bad compression or a timing problem as far as my level or expertise (or lack of) tells me. As for the camshaft, worn lobes do seem to be an issue on the Vortecs, so I may have to look in to this if the injectors aren't the problem. The fact that my trims are all over the place seems to make the camshaft theory unlikely.
I will be testing the spray patterns tomorrow and I'll post back with results and maybe a couple of pictures if I feel the need to post them. I sprayed compressed carb cleaner through them last time, but my rig wasn't good so it was hard to watch the pattern while fumbling with power supply switched, holding wires to terminals, and operating the carb cleaner spray nozzle all at the same time. From what I remember, The spray was cone shaped, but it was more of a spritz than a mist. Also, I'm not sure how many psi the cans of carb cleaner produce, but this time I should have no leaks since I used the shrink tubing with an adhesive lining to go from the tiny straw, through growing fuel line sizes and finally to the size of the injector inlet. This time my rig is much more user-friendly so I should have a free hand for pictures and slow mo video. I'm also going to remove and check the basket filters before flushing them with carb cleaner again. I may soak the tips for a few hours beforehand also. Is there any harm in supplying the injectors with a constant 12v with no pulse? Let's say maybe in 20 second intervals? I will be shooting cold carb cleaner through them so I don't think heat would be an issue. I may end up using my old fuel pump to make a testing rail rig if nee be. Thanks everyone for all the suggestions. So far you have been much more helpful than one of the Chevy forums I have wasted my time on typing huge posts with no answers.
I come on here and type a tiny bit and everyone jumps in to help and it's not even a car forum.