ECM is the engine control module. The computer that runs everything.
My truck has a horribly long start as well. BUT it's opposite of what the OP described: mine only does it on the first start of the day. After it's warm, or even just driven at all, it starts pretty quick.
The first start of the day is awful though. Sometimes I can crank it for like 5 seconds (which is an eternity...the engine turns over like 15 times) and it even then it won't start. So I stop and try again, and then it catches on like the first hit.
And every once in a while....it makes a bad clanging sound at the very end of a long crank if happens to catch and start. The truck has a brand new OEM starter within the last 2 months. Spark plugs only have 20k miles on them. Wires are older....but this doesn't seem like a wire problem at all.
You should check to see if you still have residual pressure in the morning. Before you start you 4runner, break open one of the banyo fittings on the fuel rail and see if gas comes spraying out. If it doesn't spray out, you might have a leaky check valve, a leaky fuel injector or a bad pressure regulator.
If you have a stream of fuel coming out, the your Temp sensor might be bad. Ecm doesn't know if it is cold or hot giving wrong starting programs.