GM-GMC: starting issue, chevy tahoe, costly mistake

Question
hi i own a 2000 chevy tahoe. i have experiencing some starting issues. there are times where the truck only cranks and does not want to start eventually it will but it was not like this before. i normally have to hold the key in the cranking position for more than 20 seconds. this happens mostly in the mornig. what could be the problem.

Answer
Before you start one morning, check your fuel pressure.  Should be 55-62 psi relatively quickly after turning your key to the on position.  If you have a long crank condition it may be taking too long for your pump to build the pressure required to start, or something is allowing the pressure to fall overnight.
Check your fuel pressure and go from there.  I suspect your fuel pump is faulty, but some preliminary checks will avoid a costly mistake.
Hope this helps.