I have a few questions about a 99 Chevy Silverado 1500 LS 4x4 Z71 that i was hoping SOMEONE could answer for me.
1) I'm looking for better ways to improve gas mileage...whenever i drive over 60 mph i put the tailgate down...does this really help? Also which 4x4 setting should i have selected while driving? Obviously neither HI or LOW 4x4 is a good choice but there is also a choice of 2 HI or 4x4 Auto AWD. Which one would be a better setting to save gas and would be easier on my engine?2) Recently my fuel pump went out and i had a friend replace it who is a certified mechanic. However, since then when i try to start it up for instance on a hot day or if it had been running for awhile before i turned it off then it will "churn" for a little while before it fires. In the mornings and when cooled off it starts up with no problems. What could this be? Is it simply a starter going bad or did the timing get thrown off somehow? Keep in mind this only happened AFTER my friend had replaced the fuel pump...nothing was touched other than that during the process but could this have triggered something else?