DeCaff2007
I'm Awesome
STOP!
With the timing connector plugged-in, I'd expect there'd be 12--15 degrees of advance at idle, if the initial timing with the connector UN-PLUGGED is at GM spec of TDC (zero).
If you have only 5 degrees of timing advance at idle, when the connector is plugged-in, you're WAY short on advance. This is almost certainly why the headers glow.
With 5 degrees of extra advance (5 advanced from zero with the connector unplugged) you'd likely have close to 20 degrees of advance at idle with the connector plugged-in. This will not hurt anything during cam break-in; you might want to re-set the ignition timing to spec once the engine is running nicely and the cam is happy.
Realistically, adding 5 degrees of advance probably wouldn't hurt anything long-term. I ran more than that for awhile on my '88 K1500 5.7L; but backed it down later.
NOT at idle. Engine not running. I mean 5° advance by turning the distributor CCW and eyeballing how things line up. Remember those pics you showed me? Ok well I lined up the "spikes" and then turned the dist just a HAIR. No idea where the timing marks line up. Be nice if I had a way to hold 2500 RPM while not in the driver seat.
Are you saying set it back to zero, or keep it where it's at and UNPLUG the timing connector?
Is this a one-wire (not electrically heated) sensor, or a three-wire (electrically heated) sensor?
One wire. I don't think it's too far down stream. Aside from the added length of the headers, it's just about in the same place the original was.
If what you've said in the previous post is right, you need to advance the timing before firing the engine.
My bad, I should have mentioned that that's NOT at idle.
No. I'd expect the emissions equipment to be very similar from '89 to '94. Perhaps not identical, but similar.
Well, IIRC, the '88/89 crap had a threaded bung in the passenger exhaust manifold, leading to a giant check valve. Then, that led to all the rigmarole on the intake manifold. I believe there was a smog pump in the works, too.
The '94 simply has a MAP sensor, an EGR valve, and there's a canister purge solenoid in there somewhere.