friends 2000 7.3 wont start, just crank and crank tried to fire but nothing in the cold leave it pluged in and it starts leave it in a shop over night and it starts with a shot of either ( not my doin) he is a truck driver and the truck will sometimes sits for 6 weeks at a time this time 2 weeks before I touched it
he wanted me to install a fuel pump so I did and started the following


cracked fuel lines to see if I had fuel psi at both heads


I tested glowplugs they all read at 0.3 on all 8
I have power to harness as the same at both sides of the relay
rpm tach jumps
oil psi gauge rises
usin my phone I can read hpop and 2000 at crankin (how accurate that is im not 100% sure)
all fuses good

 

If it starts and runs when plugged in, but not when stone cold, and the glow plugs test OK, my first guess would be GPR. Next time it's cold bridge the big terminals on the GPR with a screwdriver for 30 seconds or so then try to start. That will energize them long enough to do their job usually.

If there's been a lot of work recently make sure the GPR is wired correctly. Below is a handy pic from PaysonPSD.

No ether! If the glowplugs were working and the ether goes kaboom at the wrong time... can do some damage.

 

Last link in my signature may help.

 

If you want to read a view a saga, check out my cold start thread linked in my signature. If it doesn't turn out to be something electrical like the GP relay, harnesses or the GP's themselves...the answer is in my thread.

 

i apprechate it a bunch yall and il check, it looked to be right and the GPR looked new (only thing clean under the hood) and he said they was all replaced a year ago

and yes i HATE either very bad idea so i told him ito stay away if possible hes an old farmer guy with a 400K miles on the 7.3 thats hasent been touched much he sais stock injectors leakin everthing and 150K on farm roads

 

i did a quick rear thru and skiped around and took notes so i have alot of diag to do so ur problem ended up being injectors?

the owner told me hes never replaced the injectors and the truck is sittin at just shy of 400K once running it dosent seem to run badwith power i wont say its stough but wont say shes wore out either

 

Mine was injectors and once I could get her started and warmed up, she ran great once warmed up and I could restart if there had been a heat cycle within 8 hours or so, but if I let the truck sit for longer than that below 50 degrees, you could almost forget about it. Got new injectors and it solved that problem until other things popped up.

 

thanks for ur thread im sure it will help me out a bunch!! ans glad u got it fixed