NEEEEED HELP.......my 2000 silverado 1500 2wd 5.3 liter v8. heres the problem.in the morning,or first engine start of the day the truck starts immediatly with no problems.after the first start ,off and on the engine will just crank over for a few seconds before it starts....and when it starts, its a very rough idle for a few seconds.and a heavy smell of gas. engine runs great at all speeds but runs rough while at a stop.but does this inconsistantly..i replaced the spark plugs,and the engine started fine for a day.then went back to the same issue.i then replaced the fuel filter and the engine had no problems starting for three days.then went back to the same issue...the service engine light has been turning on and off at the same time.ive noticed also that the feul gauge, while at a stop while drop all the way to empty,or flucuate rapidly up and down.upon acceleration will go right back to normal level..this also happens inconsistantly. had the diagnostic done and they provided me with the codes..p0300-random-multiple missfire detected and p1416-air system (bank 2)... does anybody know what these mean? or has anybody experienced this problem ? or like problems?

 

Sounds like the Spark Control Module to me. In my '94 Silverado it's on my my distributor under the cap. Not sure where it would be on your truck. Take a look at a Haynes or Chilton book for it's location.

Has the truck been idling high and shifting rough? If so also take a look at your Throttle Position Sensor!

Good Luck!

 

Pull the vacuum line off the fuel pressure regulator and see if it is full of gas. Do this when it is hard to start.

 

thanks for the advice ..no, it doesnt idle high or shift rough.but sometimes it stalls when shifting from park to drive.but only when it is first started. not during driving

 

thanks for the advice. i appreciate your time and knowledge.tomorrow i will pull the vacumm line off the fuel pressure regulator and see if its full of gas, when its hard to start....and if its full of gas what does that mean? by pulling the vaccum line what will this do for the problem?

 

Had the same problem, Had to change the fuel pressure regulator.