I had to walk away because sometimes it's better to walk than to use a hammer. So first, the history.
'95 Chevy Suburban with a 350 (5.7L) TBI seized when the oil cooler lines separated from the radiator and my wife didn't notice the gauges. So no problem, I needed a stronger motor anyway. I'd been eyeing this 383 kit from Powerhouse for my '69 camaro so why not put this torque monster to work in the 'burb... 4 weeks and several hours later, 383 is installed with an Edelbrock Performer manifold, cam, and TES headers to boot. Heads and TBI remained stock.
So she's running... albeit a little rough. It sounded like it was missing and the new headers confirmed that cyl 8 was colder than the rest (no discoloring). Sure enough, spark plug was wet with anti-freeze. I didn't use RTV around the water jackets. Damn, my bad. New gaskets, gaskacynch, and black RTV and the leaks are gone.
But she's still running rough. Checked #8 again and this time it's hot like the others. It could still be missing but I don't know. Maybe it's the cam, but I wouldn't expect that from the Edelbrock Performer.
So rather than chase my tail, I checked timing. Timing is right at 0 degrees with the timing wire disconnected (bypass mode). With it connected, it's beyond the timing marks BTDC. I assume that's normal. What's interesting is that when I give it full throttle, timing drops below 0, maybe 2-4 degrees ATDC, it pops and then jumps back to high BTDC and revs nicely. Normal?
Another data point is when I took it for a test drive. At half throttle it knocks pretty good. Hmmm, never did THAT before... ;-)
And last, WOT, similar to that while playing with the timing, pop, accelerate, hesitate, pop, accelerate, hesitate, pop... Definitely never did THAT before. :-D
So I'm thinking:
o Maybe it's missing, it could be the plug wires (the plugs are new). o Knock sensor? o Perhaps timing needs to be remapped for the 383? o Too lean, bigger injectors? Not enough fuel pressure?
In reading about the knock sensor it says not to use silicone sealers as it may isolate the sensor from the block. Well I used RTV on that bad boy because I didn't want it to leak. Interestingly enough, the Chilton manual says in order to remove, just unscrew it. So I thought maybe it doesn't hold anti-freeze and I used RTV for nothing. Went to remove it, anti-freeze everywhere. Plugged it back up and walked away...
I know there are possibly multiple things wrong here but I'm not really sure where to start. Ideas?
Thanks, Omar