Good produce/consume strategy in RftG
One problem you may be facing is that you're trying to play this game strategically.  RftG is must more tactical than, say, Puerto Rico, since your choices of developments and planets is determined by the luck of the draw than being available for purchase.  If you 'set out' to do a produce consume before the game's begun you're putting yourself at a severe disadvantage.

A second thing that may be going wrong is that an engine strategy has a key point where you need to stop building the engine and start running it.  If you feel like you need too much time to build the engine up, perhaps you're building too big of an engine.  Aim for a smaller engine, and then work it that extra couple of times.  You'd be surprised at much even a 20% more 'efficient' engine costs.  Often it's two or more extra produce/consume cycles.