RE: Fuel? Glow plugs?
My thoughts for what they are worth.
If you can get hold of McCoy MC 59 glowplugs give them a try. I had terrible luck with the Traxxas plugs. They constantly died. The MC 59 tunes better for me and you can use the EZ-Start with out messing up the spring on the end of the wire.
As for fuel, I run Trinity Monster. It's 20% nitro and 12% oil. I find it tunes much better than the traxxas fuel and doesn't tend to swamp the one way bearing with oil.
Just my $.02. Best of luck and I hope your son has many more happy days.