Hi!
I'm new to this forum. I have a AQ271C(GM 350). I've had troubles with it not running smooth, idling, and sometimes does not start at all.
I upgraded with a HEI distributor, but the old coil wires was male connections to the distributors. I managed to press them to be semi firm on the distributor. Then we had a guy to adjust the timing advance to 30 deg (a drag race mechanic with long V8 experience). Then it ran really good, but the wires kept falling off, so I bought a new set of Summit wires+crimps (DIY kit) that fit the HEI. I thought I remembered where cyl1 was, but it was impossible to start (firing order was tripple checked). I moved them all one step and it ran really good. I borrowed a stroboscope and found it was only 10 deg. I tried moving them two steps back. Not possible to start.
How can this happen? Going from 30 to 10 deg? Unless I totally messed up where cyl1 used to be.
I thought moving the cyl1 one step on the distributor would cause 360/8 = 45 deg change? So moving from the originally 30 deg would end up with -15 or 75 deg? Anyway, I moved the wires back to where it ran semi-smooth (10 deg), and adjusted the distributor to 30 deg. It ran less smooth than 10 deg. The drag race mechanic told us 30 deg would be good (he overhauled the engine and put Summit alu tops and an edelbrock carb on a few years ago, so he knows the engine).

I started going over the wiring, and measured only 6.8V on the + on the instrument gauges. Disconnecting one and one gauge made the voltage increase +0.5V to +1.5V for each gauge disconnected, ultimately ending up on 12V without nothing connected. However with everything connected, it starts and runs ok, but instruments are not showing anything. Until I rev it (2-3000 rpm), then all needles jump up and work and the voltage also jumps to 13-14V.
This is strange since I have disconnected the alternator since the regulator is broken (waiting for a new). What can "produce" voltage when it does not have an alternator?
Could there be a stuck solenoid or something, that "loosens" up?

 

if your alternator is out of the circuit, you should be seeing battery voltage (ie 12.5V or so) A bad voltage regulator could be shunting the voltage or some other device is draining enough current to drop the voltage so you may want to disconnect more stuff (relays/fuses) until you can see a full 12V at the guages. You may find a device that is sucking down the current along the way.

 

The alternator is connected + and -, but the regulator is disconnected, so I would think it would not charge anything.
I improved the ground (-) from the battery to the instruments and it now runs super smooth. Can balance a quarter on the block.
Also, instrument gauges kick in immediately and 12V rail is consistently 12.5V.