I posted this earlier in the 5.4 section. Thought I'd fish it here too and see what bites!
I have a '97 Expedition with the 5.4L, 2wheel drive, automatic. It has 234,000 miles and has been practically trouble free it's whole life. I've had to replace front rotors, one COP on number three, one ball joint, the alternator, and a rear axle seal. The rest was general maintenance stuff like filters, fluids, and a battery.
The problem I started noticing about a week ago is that when the key is turned, the starter engages and just drags a couple of times then spins like it ought to and it fires up. When the vehicle is turned off with the engine at full operating temp, like at a gas stop, it almost doesn't restart. That is when it mimics a low battery. But it always seems to get that last "umph" and spin it over and start the engine. Hot starts seem real difficult. Yesterday, during a hot start, the starter drug to a stop enought to kill all the power and affected the electricals so much that the radio went blank and I had to re-set all the presets, but it did finally spin it over and start. So I guess the problem is progressively getting worse. Hot starts are worse than cold starts, but the problem exists all times. I've checked the battery and it passed. It's four years old and it is a seven year battery. The cable ends and the posts are clean and have zero corrosion. I do notice at the starter that the exposed end of the copper ground cable does have the copper green tarnishing so I jumped in another ground cable just to check and the condition still exsisted. I am having the battery load tested again today at a different location, just in case. But once it gets past the initial drag, it spins like it has plenty of juice. Is this how a starter acts when it starts going bad? With the related radio stuff, am I having problems with the ignition switch? I'm open to any and all suggestions! Thanks for all info provided!

 

you need a tester that can read the amp draw when starting
to check if the starter draw is in specs

 

OK. I have access to a multi tester. Where should I look for the specs and the proceedures for checking?

Thanks for the quick reply!

 

You will need a professional device like a VAT 40 to do a good draw test like mhg suggests. Average is like 200Amps and a bad starter would draw 400-600 amps.

I know you said you had the battery tested but Ive had them pass with flying colors one minute and drop a cell the next. Also a good ground to the block is essential so you can try cleaning the block and cable end there too. Or a corroded battery cable within the sheathing is possible and you are getting a substantial voltage drop possibly.

 

Thanks, I'll check the starter in the morning. For the battery, I'm swapping a known good one out of one of the other vehicles I have just to rule that out for sure.