98 yukon won't start

[damdash]

I had just left work and about 5 mins into driving the truck just killed. After rolling a block or two to get of the highway i tried to restart it. It was to late and dark to do anything so after around 4 unsuccessful attempts i left the truck there till the next day. When i went back i tried starting fluid 2 or 3 times and still no start. I hear the fuel pump come on and i checked the fuel line valve. I noticed that when i turn the key the gas needle goes from 1/4 to pass full and then back. Right now i am baffled as to what this may be. Any suggestions will be greatly appreciated.

[maxwedge]

Well start by checking for spark, if there was spark it should have started with the starting fluid, but basic diagnostics are in order here. If spark, get a fuel pressure gage on the rail and look for 60 psi.

[damdash]

it has spark, i hear the fuel pump. i was told it could be the computer. how likely would it be the computer? also i had this problem about 2 years ago and my first thought was the fuel pump. when i dropped the tank i messed with the wiring and it started right up. my plan is to do this tommorrow if it doesn't rain and if that does not solve the problem i will finally take it to a shop.

[damdash]

ok so it turned out to be that the distributor cap burnt around the center contact diverting the spark or something like that. I changed that and the rotor and it fired right up. The mechanic also stated a blown head gasket. I just let it run for five to ten minutes and the needle is only a notch or two from the red. Well, I have another block so i will just put that in and take the old out. Is this something to complex for an intermediate with a chilton repair manual? Also i know that it will need new oil, oil filter, spark plugs and wires, and antifreeze. Is there anything else i missed? I just changed the cap,rotor, and fuel filter not even twenty miles ago so i didn't list them.