I agree



I think these things would account for your high readings at idle, especially if the gap on the plugs was huge and the filter was really clogged.


I say change your fuel filter. An engine uses more fuel when under load (moving the vehicle down the road) than when under no load (revving in neutral). Your fuel filter may have been clogged to the point of allowing enough fuel through to rev the engine under no load but not enough when the engine was working hard turning your transmission, t case, driveshaft, diff(s), axles, wheels, tires, and moving 2 tons of Yota down the road. Fuel filters are kinda pricey and can be a pain to replace but its good to cover your bases. EDIT: A weak fuel pump could cause this too.



The seafoam may have cleaned a little bit of crud out of your fuel filter, allowing more fuel flow. A partially clogged fuel filter could be the cause of the intermittent low idle you are experiencing now.


Just my two cents

 

Well look what I found...

I opened one of the side compartments in the back and found 2 jacks and a fuel filter. Looks like the previous owner bought one but never installed it. score!

 

I have a first gen with a similar problem.

Mine will die when it gets warm. If I spray carb cleaner while it is thinking about dieing it will putter more for a second and then fire right back to running good. The good running only lasts about half a minute before it starts to putter again. I have used a lot of seafoam and will be draining my gas tank and changing the fuel filter and a few lines today.

Have you changed your fuel filter yet? Are your problems fixed?