#1 If you undo your connections, you'll have 4 ground wires: 2 to the module, and 2 from the vehicle harness. Solder all 4 together, (along with the 10 ga wire) using 60/40 lead/tin rosin core solder. Attach the other end of the 10 ga wire to a good clean body or chassis ground. Don't rely on the ground strap on the filler neck. The injectors are ground pulsed by the PCM, using individual isolated circuits directly from the PCM to each injector. Modifying the level sender and pump grounds has no affect on the injectors.

#2 Camshaft retard adjustment is done by rotating the distributor. The distributor housing is squared and the bracket slides onto it, much like an open end wrench onto a bolt. When you turn the distributor in either direction, it moves in an arc due to the differences in diameters of the distributor and the intake manifold.

#3 Ignition timing and camshaft retard are two different things. If either of those could access camshaft retard, it would be a selling point. The fact that they don't specifically mention camshaft retard, means they most likely can't access it :(

I spoke with the mechanic again today and specifically asked him about the cam retard procedure and his scan tool. He said his is made by snap-on so I guess it's a good one. I told him I am confused because all the people in the S10 forums who know these cars like the back of their hand say that you have to loosen the distributor and rotate it. He looked at me confused and said "there isn't even any room for it to rotate once you loosen it because the bracket is slotted 90 degrees off (meaning towards the hold down bolt) and not slotted to allow for distributor rotation. It will only rotate like 1 or 2 degrees in that narrow slot once loosened"

I must admit that when it's loosened, it really doesn't rotate much at all. This is why I asked previously "how do you rotate the distributor for this" because mine doesn't really "rotate".

I had an old '89 VW and on that car, you did loosen it and rotate it with a timing light. I realize this car does not use a timing light. My point is that with the VW, it was very obvious that it was designed to be rotated during tweaking. My '01 Vortec is not obvious, at all. The hold down bracket keeps mine from rotating, even when loosened, so I'm really confused.

I also am having a hard time verifying which scanner products can or can not perform this. I am BIG on DIY, so I'd rather invest in a tool and do it myself than put $50 (or more) toward paying a mechanic to do it. But I don't know what the least expensive option is for me to buy that will allow this.

Ugggh.

Depending on which Snapon scan tool he has, it should be able to access camshaft retard, (not all Snapon scan tools can access it).

Repair shops don't take kindly to customers telling them how to fix cars ;) After all, he's supposed to be the professional, not you ;) Trust me, you'd be better off to find a technician that's familiar with camshaft retard, what it does, and how to adjust it. Labor charge should be under an hour to check & adjust it.

You're right about timing lights: they're obsolete on this engine. On engines that have points, or a pick up coil & reluctor wheel in the distributor, timing is adjusted by rotating the distributor and viewing the marks with a timing light. On 1996 & newer 4.3L, once the timing chain & gears are installed correctly, the PCM has full control of ignition timing, rotating the distributor does not change it.

Read post #7 again. When you loosen the hold down bolt, the distributor does move slightly, and that's the adjustment.

There's a ton of used Snapon Solus, and Solus Pro scan tools on Ebay. Annual software updates are $1K, (available only through Snapon), so make sure it will cover your 2001.

Its the software that gives you the option of checking cam retard. You require the software package Scan XL with the GM Enhanced package in order to read the CMP PID.
Go read the post on ZR2 #16 that I answered for you.