4.3 liter wont start on the first crank.

Random Misfires means just that - the computer doesn't see a misfire on the same plug all the time.

Some things it could be: 1. Clogged fuel filter - when did you last change this? 2. Fuel pump 3. Fuel pressure regulator 4. Rotor, Distributor cap 5. Plug wires (unless changed when you did the plugs)

Save 2 and 3 till later, do 1, 4, and 5. You might also get the computer scanned with a higher-quality scanner - there are often codes scored that won't turn on the check engine light, but which can provide clues. The Autozone scanner they use for you, as I recall only pulls "set" codes (ie, once the light is on). A dealer or independent shop will have a much better scan tool that can provide more info.

A few other th>I'm wearing out my starter. It takes 3 short cranking sessions to start

If you pump the throttle while she is cranking and the computer sees the reading of wide open throttle from the throttle position sensor it shuts the fuel pump off assuming your telling it it is flooded. Next time watch the oil pressure gauge when your cranking, if she starts when then oil pressure gauge hits 10psi, check the fule pump relay. The fail safe if the relay goes bad is the oil pressure switch. Also when you say 3 or 4 short cranks, are you turning the key completly off and then back on each time you do it? what fuel injection system?

I'll agree with Miller, change the cap and rotor and wires, and don't use a cheap nor Bosch wires, GM's can burn a cheap cap and rotor in short order. AC Delco wires or Packard's(who make AC Delco wires) work best. Use dielectric grease in cap and plug terminals, and anti seize on the plug threads, and don't over tighten the plugs.

Whitelightning

Had a similar problem on my 2000 Yukon XL, 5.3 liter. Actually, it still has this problem, but in my case there was an easy way to live with it. I discovered that the ignition switch is either out of adjustment or slightly defective. If the switch is turned fully to the "stop" when cranking, one of the contacts apparently opens and the fuel pump shuts down. If I only turn the ignition switch just enough to engage the starter, it fires up first time, every time. What was happening before was each time I cranked the engine, it would receive a very short burst of fuel as the switch went past the "good" portion of the contacts, and therefore repeated short crankings would start it, where one long one wouldn't. Worth a try.

Jim M.

I have a similar problem with my sonoma..sometimes it cranks right away...sometimes it takes 3-4 cranks...i will try turning the key just enough to engage starter.