I "fried" a set of plugs on a 65 miles per hour plus (time constraints) run across the U.S. with a 3VZE powered, 6000+ pound 21 foot, Motorhome. I replaced the Champions (installed by former owner) with a set of colder NGKs, but I would still like to improve the ignition system. Cap, rotor, and wires are new. Any suggestions here for an aftermarket system? Oh yeah, I'm open to any simple bolt-on power or mileage improvements too.

 

What do you mean by "fried"? Burned the electrodes I'm assuming, by your choice of a colder plug.

To me, it sounds like you're either leaning out at higher rpms, something you won't fix by upgrading the ignition system, or have too much ignition advance.

 

By "fried" I mean it ran very bad, very hard to start when I got home. I knew I ran it hard, lots of long third gear pulls, so I pulled the Champion spark plugs, installed NGKs, and it starts fine now. I don't think the ignition caused any plug problems, I just want a better spark. I also think I may have got a tank of bad fuel during my cross country trip, through part of WV it ran especially bad.

 

The stock ignition that toyota used is actually quite good, provided that you keep up the required service when needed. Make sure the timming is properly set and the valves are adjusted properly, cap, rotor and plugs are replaced when needed and you shouldn`t have any problems. Also using good quality gas helps alot.

 

Have some pictures of the Champion plugs you pulled out?
That would go a long way in helping to figure out things.

 

I tossed the plugs, but they were gray, not the usual light brown. They didn't look very bad, the diagnosis was more by the "seat of the pants". My next step is a good fuel injection cleaner in the tank and cleaning the throttle body. If that doesn't help it's off to the local repair shop. It's getting cold in PA and my shop door is only 8' tall. The RV is 9 1/2' high, and I don't relish seting the valve clearance in the cold.