2001 7.3 very hard starting issue

Hi

I have a 2001 F250 SD 2WD pickup with 171K miles on it. It gets used a bit for around town driving, and a few travel trailer trips each year.

It's always been hard starting in cold weather, and I've gotten around this by using the block heater. With an overnight heating cycle, it starts right up. If I'm somewhere where it can't be plugged in overnight, it takes many tries to get it to fire. I've been through a series of new batteries, and I've taken to just replacing them every two years. The usual cold start process without the block heater is to the turn the key on, and wait about 20 seconds until I hear a relay click (off?) which I believe is the glow plug relay, then try to start. This can take anywhere from 5 to 30 tries of this cycle to get it to finally fire. On the cold days, the batteries will give up first.

Now, there is a new issue which is adding to the problem. Even in summer weather, the first couple of engine cranking cycles act as though the batteries are weak or almost dead, but as I try more times, the cranking gets better, eventually the truck will start. I replaced both batteries with new ones yesterday, verified the terminals are all clean and tight, and today it made no difference. The first few cranking tries act as though the batteries are almost dead.

Could this be a starter problem, with it drawing a LOT of current when cold, then getting a bit better after some cranking?

I was going to attack the cold start problem one thing at a time, batteries were first on my list but that's obviously not the issue. I was thinking the glow plug relay next, as easy to change and not expensive. The next step would be to have a shop dive into the glow plug situation.

If you’ve never changed the glow plugs I would start there. The reason for the “eventual” faster crank is due to the build of oil pressure.

Definitely start with glowplugs, then the slow starting issue is due to over use of the starter you are simply wearing out your starter which may be the original unit. I bought my 2003 7.3 F250 in 2010 It was a fairly high mile truck with 260,000 miles but in good condition and a 7.3. I have replaced 3 batteries, never bought into the buy by the set idea and never had a problem. When the truck started to have slow starting issues I replaced the original starter in 2018 and problem solved. While you have the valve covers off check the valve cover harnesses, I replaced mine with the one that eliminates the inside connector.

The problem is solved, and I couldn't be happier with the results! The truck has never cranked so fast, and started so well! Since I bought the truck used, I didn't know what I was missing. There was a 2001 Excursion with a PS next to me in the campground in Sept, and after listening to his start on a cold morning I realized what I was missing.

The starter was so bad it wouldn't even run on the bench test after it was out. It was replaced with a new (not rebuilt) Denso starter. The glow plug relay was also replaced. The glow plugs tested good.