7.3 hard start

[Motorwerx]

Could also be a starter? We replaced both batteries, all the battery wiring, and the alternator, and it would still slow crank in the mornings. Would occasionally start immediately once it was warm like you said yours did after the highway test, but after replacing the starter ours starts immediately every time, even at freezing temps.

[arctictraveller]

Low battery voltage will cause the glowplugs to operate at a lower temp, so getting them load tested might tell you something. Additionally if the oil drain back valve in the HPOP reservoir is leaking, the lack of oil will not allow injector firing pressure to build adequately until the reservoir refills from extended cranking. It’s easy to check, after sitting overnight, remove the fill plug and insert a small screwdriver to see if it’s full.

[robertg]

One thing to also consider is that Diesels don't like to sit for long periods especially during the winter. Diesel tanks lend themselves to water condensation and algae growth. So remember to pre treat the fuel prior to a long winter nap! (Just replaced a fuel tank in my dads 7.3)

[shenrie]

Glad you got it figured out the cheap way. Very rare...

There’s a few threads around here regarding using a later model starter from maybe the 6.0? A few here have made the swap and we’re happy with how much faster the later starters spin. I definitely feel like my rig would start faster when it’s cold out if it just turned over a touch faster.

[REF]

Just to pile on, I installed a mean green starter on my 7.3, seems to fire up much better

[Timerider]

Glad you got it fixed!

Out of curiosity (and possibly vested self-interest), where did you stop for fuel in Bishop? Paiute Palace? Yuhubi Nobi? Speedway? Sinclair? Someplace else?

[northleftcoast]

I’ve had similar symptoms with a bad glow plug relay. It is easy to diagnose and cheap to replace. I’ve had to replace a couple over the years on a 250k + 7.3 van and f550.

[HIGHCOUNTRYMIKE]

Yes I stop at Paiute Palace and at Independence Casino and Truck stop.
It did set for almost 2 months and I was nrglectful in not starting and driving it to keep things fresh.
Just came back from 3,000 miles in AZ, NV, UT and Wyoming.
Everything fine except steering alignment and heater function.
Both of which I just posted questions about solutions.
I included a venture into Gold Butte N M NV.