Hey guys, my engine has been acting weird lately.  When I drive my car like a grandpa, it seems to run fine, but if I get on it a little bit for fun, or say to go up a steep hill, it will hesitate to the point of vibrating the whole car and start popping and normally backfire once.

Now I'm thinking plugs, plug wires, maybe timing?  I used to have a problem with my #1 plug wire, the car would hesitate a bit, so I would replace it and no problems in the past 1 1/2 years, but it never used to pop or backfire.  Not sure what it is exactly, if its something new or if I'm just completely wrong.  I'm really broke right now, so I can't really afford to fix anything, but in the mean-time, any help to steer me in the right direction would be great!!

It won't cost you anything to pull the plugs and make sure everything's firing ok. If they're ok, take an emory board to them, gap them, and put them back in.

It really does sound like it is misfiring under load.  Perhaps another bad wire, weak or cracked plug, etc.  Look for tracking inside the cap as well.

I light up the tires on my Seville every once in a while for fun and I'm a grandpa. 

Yea, so I have seen so far.  They are great!

I will have to check it all out tomorrow.  But just one question:  I have seen pictures of tracking so I know kind of what it looks like, but what does causes it?

And FYI, I'm driving a '75 Ray with a 454 put in it by the last owner.  Bought it in 2006, and I've done what feels like a lot of work to it, but I'm still pretty new at mechanical stuff, so explanations are a huge help.  Autobody is what I know best!!

Tracking starts when the spark jumps where it is not suppose to go.  It can start due to high resistance from bad plug wires, etc, or from contamination and/or moisture allowing a current path.  Under light load, the spark goes where it should, but when the throttle opens, more air gets into the cylinder creating more resistance to the spark jumping across the plug gap, and the resistance goes up, then the tracking can start at any weak point.   Tracking also occours at the outer surface of the spark plugs.

I've had problems like that many years ago. The problem was with my distributor advance mechanism.

Ok, so here's a little update.  Finally had the time to check out the plugs and plug wires.  Plugs were good, but my #1 plug wire was all cracked near the headers.  When I pulled it out, I saw some small black spots on the header itself. 

I had one of those spark plug wire covers on the wire that you can get from a place like Autozone, but it looks like it still arced, through the fiberglass, to the header.   Is that was caused the backfiring?   And any suggestions as to what to do so that this doesn't happen again? 

A plug wire arcing/shorting to the header can definitely create a back-fire situation.
Does your engine have the sheet-metal/barrel plug wire shields? These are a must for big-blocks, but of course, they may not fit with some types of headers.
You may need to change the plug end of the wires to 45deg ends(or similar), and make sure the wires are secured away from the headers. The insulation works fine in most cases, but....if it lays up against the headers too long, eventually it's gonna burn thru...

There are a couple of other threads about plug wire insulation here somewhere. There were several members that had tried a few things with good results, so you might try a "search" to see what comes up...Adams' Apple2008-09-15 19:38:32

Excellent, thank you!