I need some help from the diesel community. My brothers son has a '85 F250 with 6.9l diesel. The truck would not start. A new mechanical was installed as well as an electric pump installed.. The injector pump was replaced with new, a new fuel filter and all 8 injectors were replaced. The only way to get the truck starts is to remove the glow plugs one at a time and spray diesel in and reinstall. the truck starts right up and runs like a champ....Also a compression check was done on all 8 cylinders, all good. As soon as the truck is shut off then will not restart......Are we missing something???? Only thing we can think of is maybe the batteries are not strong enough to spin the engine fast enough to get fuel to the cylinders.....Any thoughts?? We need to get this Ford back on the road...Thank You in advance for any help you can give us.

DOC

 

They do need to turn over pretty fast to start. TJCTransport posted some videos of cranking speed, try searching for them or maybe someone can link.

 

https://www.ford-trucks.com/forums/1...ing-speed.html
post #8

 

did u rebleed out the fuel system afterr all the stuff was replaced

 

I'd think if it runs ok after spraying Diesel into the chambers, then it doesn't need bleeding.

All in all, this really isn't enough info to diagnose your problem. With all those fuel system changes, I'd hope it has nothing to do with that, but you never know. I'm leaning toward an electrical problem, like the batteries, starter, etc. But before you go out and buy a crapload of glow plugs, do the simple things first. check your voltage. And not with a dummy light. get a multimeter and if you are below 12.3V at startup, then your batteries aren't going to start up these old beasts. Then you have either batteries that aren't taking a charge, an alternator that isn't charging, or, if it applies to your vehicle, a voltage regulator that is malfunctioning. Or a starter problem. Or relays/links issue.

Wait. did you install new glow plugs? If yes, did you install Motorcraft brand plugs? if not, pull them and get the good stuff.

 

After it is warmed up, get access to a hd battery or 200 amp charger and see if it will start. If it does, you have battery or cable problems. If it doesn't, well move in to check the starter.
I'm not good at injector problems but someone here may be able to tell you how to check if your injectors are spraying fuel while cranking.

Steve

 

If it runs with the prime, then the injectors are spraying. It seems to me that the engine may not be turning fast enough. Starters can sneak up on you. They take long enough to wear out, you don't even realize they were turning so slow until you put the new starter on. My last starter was getting tot eh point the motor would crank, but just wouldn't fire. I finally caught on (after continuing to limp on...) and changed the starter, and it was night and day difference in cranking speed.

 

White smoke from the tailpipe while cranking is unburnt fuel. If you get that it either isn't cranking fast enough, glow plugs aren't working, or compression is low.

 

if that was the case it would run on it owen after he got it started but pouring diesel in the glow plug holes the op replaces the fuel fliter and if he dint fill it back up with fuel expalns y he can squirt diesel in to the gp hole and the truck will start with indicates the glow plugs are good and the truck is spinning fast enough to start to the op crack open a injector line and crank a injector line and see if u get fuel out of it then repeat with all 8 injectors