Ford 7.3 cold start, 7.3 diesel problem starting in the cold 

Little trick I learned from a bus mechanic. Turn glow plugs on let them cycle once. Then turn key back to accessory for 15 seconds. Then fire her up. Works every time. He told me "some 7.3s are just hard startin sumbitches" they had 6 buses out of their whole fleet that just did that.

Thanks for the help!

Exact issue I had with my 96 a few years ago, and exactly how I figured it out. I knew the truck was gonna need some TLC when I inspected/bought it with ~228K on odo. Still going strong!

I have an engine block heater. GPR is my first suspect. I’ve had the issue and I tapped my GPR with a mallet and bam! I tried it again and it fired right up. I heard they stick sometimes. I actually have 2 of these relays. I think the second one is the IAH intake air heater and the fuel bowl heater.

Great informative vid what I did was bought a winch relay that had a bigger duty cycle than factory and it was $18 so far works great and should last longer I hope I didn't want to spend the $60+ if at all possible thanks

oh i for got to thank you for putting this clip out (nice job)

The sender to the glowplug relay sometimes keeps the glow plugs on too long and burns them out! So what I did is hook the sender wire to a push button on the dash to activate the relay. That way they don’t burn out by that stupid thermostatic sender that burned the glow plugs out. After a couple of sets of plugs , That was 20 years goo and the glow plugs are still working!... Manually!

LOVE this model truck and engine !! The GP relay is really common. In my opinion they are like any other starter relay. They burn out with so many cycles. I believe glow plugs were meant to be changed every 100,000 as a rule of thumb. Very easy to change . If you can do a LS1 swap you can do glow plugs. the only thing to be careful with is the locking clips on the inside of the valve cover gasket. They get brittle from the heat. I normally left them attached to the vc gasket and disconnected the terminal at the glow plug and injector. Take care of this truck and it will out last YOU. I would love to have one just like it 😍

Outstanding. Very succinct instructions....much appreciated.

Recently sorted out my 2000 7.3 hard/no start cold issue. Relay was bad, and used a test light and voltage gauge to test before hand. also had 1 battery that dropped to 105 CCA under load, so that also was hurting it. I heard somewhere(not sure of accuracy) that weak batteries won't allow the relay to activate the solenoid, so make ure you have 11V-12V constant, and no lower than 10V on the KOEO terminal of GPR. Only use a Ford Motorcraft relay. Same on glowplugs. Checking the glowplugs themselves for power is a PITA on an intercooled 7.3! LOL. Those harness plugs are old, and those heater hoses if original, will probably break or start leaking (mine did). Replaced with Motorcraft as well. They were due. Also don't replace the wrong solenoid by mistake, as my truck has two that look almost identical. GPR is the back one. the one in front is the air intake heater solenoid. Once you've sorted out everything with the glow plugs, here is something else. The HPOP. If you haven't flushed out that oil this year or in a long time, thoe 2 quarts of oil running in the HPOP reservoir and the heads is probably dirty and thick. Watch your dash oil pressure gauge when cranking. If it doesn't budge, until started, even after multiple cranks, it's either thick dirty oil in there, trying to fire the injectors, or the pump gears are worn. Fresh oil in there with some good additive (Archoil) will save your injectors too. A number of vids online how to easily flush this out. Don't frge your block heater is a pinch !

Very good video descriptions of problem and how to fix. Great job buddy. Thank you

Agree way to much but I'm getting old also but say same about my Harley

ah we thought ya had some trouble starting when cold as in not starting when turned over. sometimes can get the block heaters that go in freeze out plug holes. saves from having the hard starts in cold.

Good video man! Thanks.

You can make a fire under the engine with your lovely logs, that would warm up your glow plugs

I find it funny that when a Powerstroke takes an hour to start where I live the 6.2 Detroit next to it starts in a matter of a few minutes 😂

Thank you for sharing, very helpfull

Thanks

Nothing a little Cosby in a can can’t fix. Don’t forget to pin it into the danger zone with full ketchup. 👌

Nice analysis. Concise and easy to understand. Do you have link to the tester?

Ty it helped.

Thanks for the info. Btw you could be a double for Kevin Costner ☺️

Love your video….. I have a 2001 7.3 diesel but the transmission heats up and then start an oil leak any idea what could be the problem??

Nicely explain. Thank you. Need close ups to make it better.

i had a buddy who had a diesel and his fuel went to gel it was so cold.

I have 2000 7.3 Ford f350 I have changed that relay you just did and my glow plugs but it starts better but still struggles to start any ideas what to look for next don't get me wrong it's definitely better but still hates the cold

i don't understand how your prob works with it being hook up to both positive and negative ... my light has only one lead so I see the hot on the big terminal and no power to the other big terminal but not sure how to check the 2 small terminal ... ya i have a card in my pocket that says I'm slow but not stupid and i had to put up with that condition for 64 year so bare with me pls ...

I have a 96 and I've replaced glowplugs, relays, ran a toggle switch for direct fire to the glow plugs and still won't start

I changed the glow plugs and there’s nothing wrong with my relay but it still throws a fit for some reason, even today I had to wait for 2 minutes for the glow plugs to really do their thing and it was struggling to start. Could it maybe be because I didn’t buy oem glow plugs and offbrand auto lite ones from autozone?

I know im late for the party but im trying to get an answer anywhere i can.. ive got power to the relay power to the constant key on small post. No power to the other big post. Ive gone through 4 relays and an oil temp sensor. anyone have any thoughts?

I have a 2001 7.3 with no relay, but it has Glow Plug Module. Tough to start in 40 degree weather. That isn't that cold. Any idea's how to test the Glow Plug Module.

What year is your truck?

You need to be more in-depth in a close-up on what wires go where I have replaced a few glow plug relays and still seem to find having problems with the 73's in the cult I'm starting my 12 valve has an issue with starting in the cold also if it's not plugged in which it shouldn't we need more in-depth on your mechanic isms of how this actual glow plug relay works because we do not know the actual mechanic isms of it makes it a lot harder to understand yes we know that the light is supposed to stay on but how long is the light supposed to stay on and if there is no light that's a no-brainer that it's not getting power through to the other side what is their power coming into the side before it gets to the other side so that you have to be more inclusive and intrusive on your diagnosis to let other people know simplified measures to make this easier task than a difficult one there's really no schematic behind it I'm what you are showing

I am having cold start issues, and question would your engine ring rough till warmed up?