I have the 2000 F-250 Crewcab 7.3L 2WD. Y'all here were very helpful a few months back when I had other starting problems that I traced to a bad glow plug relay.
Here are the latest starting problem symptoms:
-If the engine sits longer than a couple hours or overnight, it cranks very slowly. "rumm, rumm..rumm...rumm........rumm"
-when I first turn the key but don't crank it, the idiot gauge voltmeter needle goes to only 1/3 or halfway. But if the engine has been running for a while after commuting or running errands around town, at the next start the needle goes right up to almost pegging and it turns over quickly and starts immediately.
-Only way I can get it to start after the engine sets for a few hours or overnight is to crank for 5 seconds, let it set for 5 seconds and crank again for 5 seconds. Lather, rinse, repeat but it's never had to crank more than three times before the engine turns over.
-it seems on the second and third cranks the starter runs faster
-battery posts and cables are freshly cleaned & wirebrushed. Connections are TIGHT
-took the truck to Advance Auto after work tonite. The manager was very helpful. We turned the headlights on, removed the negative cable from each battery one at a time and each tested out as good.
My Half-baked Diagnosis:
*A couple friends of mine also own or have owned the 7.3L. They narrowed it down to bad battery or batteries (before I went to Advance Auto tonite), bad starter solenoid relay or bad starter.
*the Advance manager thinks its the starter. He said the starter will drag and turn slowly when its cold but once it heats up it cranks fast. He said if its the starter and its starting to go bad, when it dies completely I'll be stuck and need a tow.
*one of my 7.3L friends said he'd had the same starting problems a few years back and it was the starter solenoid relay, mounted on the fenderwell.
*of course, the store manager said my safest bet is to replace both the solenoid and the starter but I'm on a tight budget this month due to other unforeseen expenses.
The starter is not bad, at about $170 if I fix it myself. My friend and I can do it.
The solenoid is inexpensive at only $25 and I can do that by myself in about 15 minutes even with the crappy tools I have.
I don't want to do "reconnaisance by fire" - in other words replace part after part after part until the problem goes away. I'd rather replace the right part the first time.
Any help or advice is greatly appreciated!