My truck is about to hit 200K miles and it runs and looks like new, except it has trouble starting. Every morning, or the first time that day, I go get in my truck it starts right up. But if it has been running recently it takes at least 5 to 10 sec of running the starter before it will idle. In the last year it has had new plugs, wires, starter, battery, fuel pump, fuel filter, I have ran some fuel injector cleaner in it but still no improvement. I just moved to the mountains this year, could the elevation be causing this problem? I have spoken with several mechanics and I seem to just be wasting money on the problem.

Altitude will affect a carburated fuel system as the air is thinner the engine will tend to run rich "but" in a '99 the computer would compensate and tweak the adjustment.

It may be your electric choke it may be sticking or misadjusted. This happened to my 98 Jimmy.

Try this, crack your throttle plate/butterfly valve by just barely pushing the throttle before starting the vehicle. I'm talking about only depressing the throttle pedal about 1" and hold it in that position and then try it and see if it starts immediately.

If it does, try cleaning up all of your linkage with carb cleaner and see if that doesn't fix the problem.

Is your check engine light on? If so, have a scan done to find out what codes are in the computer. When you replaced the plugs & wires, did you also replace the cap & rotor? I would also have a fuel pressure test done just to make sure that the fuel pump is working properly; I know someone who had his replaced 3 times in only 33,000 miles.

Try using a quality throttle plate cleaner and while the engine is warmed up and running, spray in short bursts while working the throttle to keep the engine running. Pay particular attention to the area where the Idle Air Control valve is mounted. If that is carboned up or sticking, it may perform well for you during initial start-up but be in the wrong place for warm restart.