2001 Jimmy 4.3L v6

I replaced the fuel pump, fuel regulator, fuel filter and fuel spider. I drove it for about a month before It broke down (The first time) I have an engine code saying "high output voltage" for the fuel (I can't remember the exact code number and I don't have access to my jimmy right now) I am also getting a random multiple misfire code. (yay..)

When I try to start my truck, it sounds like its wants to turn over (rowr rowr rowr thud) but before it can start it 'thuds' out.. every time.. My friend and I were working on it, when we opened the intake manifold it was covered in a gel (golden in color) substance, we cleaned all of that out, and my friend continued to mess with it (while I was at work) to get it running.. he finally did hours later.. I noticed that after that even though it started, it just didn't run quite right. about 2.5-3 weeks later I was on lunch at work and while I was driving I didn't have much power, It was slightly hesistating (but not as bad as if the fuel pump was going out) so I parked it and grabbed a friends vehicle.
When I went to start it later in the evening it was acting just the same as before; like it wanted to start but just couldn't.. I haven't been able to reopen the intake manifold to see if there is more gel in it, but I really wouldn't be surprised if there was.

I'm not sure what to do... is it fuel? could my timing be off? If the timing was off would it still cause that hesistation and lack of power while driving? What about the Gel in the intake manifold?

And to make things better, I now have no vehicle to use in the mean time since the friend I was borrowing his spare vehicle from now needs it since his truck broke... yay..

So far everything that has been replaced:
**Spark Plugs
**Cap (when my friend was tightening down the cap, he cracked the plastic where it connects to the distributer, its held down securely still, but the hole on the dist, where the cap screws in is broken. We zip tied it down for safe measures..)
**Rotor
**Wires
**Fuel regulator
**Fuel Spider
**Fuel Sending Unit
**Fuel Filter