Why won't my 7.3 start without starter fluid at altitude?

[gtbensley]

I have replaced mine from both places....I would say its easiest to pull the intake box and reach it from the front. Just be sure to disconnect the batteries before you replace it, otherwise you will have live wires shorting out if they touch anything.

 

[Backcountry Pursuit]

My gf's horse hauling rig, 01 F250 7.3, had the exact same symptoms. I determined with the meter the relay was bad. I replaced with the hd stancor one. Starts perfectly now in any temp and tested as high as 6000 ft. And I was getting ready to do all new plugs and wire harnesses. Really glad I simply checked the relay before going big with time, money and effort.

If you haven't found the YouTube series from Powerstroke Help, you need to watch his videos. That guy is awesome. I learned a ton. Find the video that talks about changing the oil in the top of the motor. That was another noticeable improvement after I pulled that sludge out and put fresh oil in.

 

[kccourtney]

My gf's horse hauling rig, 01 F250 7.3, had the exact same symptoms. I determined with the meter the relay was bad. I replaced with the hd stancor one. Starts perfectly now in any temp and tested as high as 6000 ft. And I was getting ready to do all new plugs and wire harnesses. Really glad I simply checked the relay before going big with time, money and effort.

If you haven't found the YouTube series from Powerstroke Help, you need to watch his videos. That guy is awesome. I learned a ton. Find the video that talks about changing the oil in the top of the motor. That was another noticeable improvement after I pulled that sludge out and put fresh oil in.

Thanks everyone. I found it. It's way in there. Ugh. Gotta love vans. Might just take it to my neighbor's diesel shop and let him deal with it and switch out plugs (and broken header bolt) while theyre in there.

 

[gtbensley]

Its not that bad, give it a shot!

 

[derjack]

Like AYIAPhoto said in his first post - nothing to add!

GP is key to be maintained! This is just 80-100 bugs for material + some work. First is always the worst! As said before: fluid WILL ruin yo your engine.

A diesel engine only works on compression and self ignition. To do so air needs to be compressed to roughly 900 degrees Celsius! In cold conditions this is not enough > GP.
In areas with lower air density it's just - obvious - similar.

If your truck only starts in "nice" conditions, I am pretty sure it's the GP/GPR.

 

[Bane Harper]

Yes the glow plug relay might be the problem child. Its painful when you are about to begin and its not waking up at altitude. Good Luck!!