Pouring the coal 

To give maximum effort or energy to an event.

To make love with added energy.

To make an engine give its maximum performance.

The train conductor decided to pour the coal to the engine when he went up the hill.

When I saw Sandy last night, I didn't just (make love). I spent 3 hours pouring the coal to her. I had not seen her in weeks!

I made it here in less than an hour. I was pouring the coal to that car.

The engineer wanted to pull more cars, so he told the conductor to start pouring the coal.

Pouring the coal by Army Medic September 12, 2013

Pourin' the coal to her 

AKA... givin' her the business... putting your cock in her steam engine... fucking...

Man I heard Todd was really Pourin' the coal to her...

Pourin' the coal to her by Baessler December 26, 2008

pouring on the coals 

Increase production quickly

Stems from old coal burning, steam engines, where the coalmen had to shovel coal into the burner to keep the train running. The more coals the bigger the fire, the faster the train could go.

General Motors is pouring on the coals in the development of hybrid vehicles over the last couple of years

pouring on the coals by anonymous2zx2 October 24, 2006