I've been fighting this truck for a while. It's an '89 7.3L. It won't start after it sits overnight. It cranks and cranks, sometimes it will finally fire, but usually requires starting fluid.
- In the past year it had new injectors installed.
-The lift pump is good.
-I remove the fuel filter after sitting overnight, and it's completely full of fuel.
-I blocked off the return line from the filter also.
-I bled all the injectors.

Could the orings be bad already? It's been a year since they were put in. It started fine for a few months after that.

 

Could be glow plugs not working or not cranking fast enough. White smoke while cranking indicates you are getting fuel but it isnt igniting.

 

I tested all the glow plugs and they were good. Light stays on ample time. I went ahead and changed my orings, caps and return lines today. I'll have to see what it does in the morning.

 

You said you replaced the injectors, did you replace the injection pump as well?

New injectors with a higher pressure to crack than older injectors could cause your IP to fail prematurely with the increased strains from higher cracking pressures of the new injectors.

 

Watch the tailpipe for smoke while you crank it. That should point you in the right direction.

 

I have an 86 that does the samething. When I first turn it over after 3 or 4 seconds it will fire up and instantly die even if I have the pedal to the floor. And puffs out a lot of while smoke. Then I usually run the batteries dead trying to get to crank.

 

plug it in over night, if it starts right up each time it is a glow plug problem.

 

your problem is air intrusion . you need to replace the return lines, caps, and o-rings.

 

I replaced the return lines, caps and orings, still no start this morning after I run it a good hour yesterday after replacing them. I'm going to have to look up and see if the injection pump was replaced with the injectors. Seems to me like he sent it in for a different one when he changed injectors. Is there a way to check the injection pump, or do I have to take it off and have it checked? Once the truck is running it seems to have more get up and go than my '97 and '00 powerstrokes. I may try plugging it in tomorrow night, It's been 100 degrees here, I wouldn't think it would need glow plugs to start. When I plugged off the filter return line, I cranked it over before I plugged it. Fuel immediately came spraying out, so I would think the lift pump is fine, and that there's no drainback in the filter, I took the filter off prior to verify and it was completely full.

 

So... did you look to see if it was pumping white smoke from the tailpipe when cranking?

 

Thanks, I have ordered the kit. I will try it out this weekend.

 

Okay, I ran the clear line test again after changing all my return fittings. I am getting some bubble coming from the return from the filter housing to the #1 injector. Also, the line from the #8 injector to the T never fills with fuel. I also have a clear line in place of the rubber line coming from the tank to the lift pump. There are no bubbles there. There are also no bubbles in the injection pump return line. I'm thinking this is pointing me to a leak in the filter head? What orings are inside, and what do I need to seal up the connections? Also, is there any check valves in there that I can replace?

After the truck has sat a bit, there is a large bubble in the injector return line, and also a big bubble in the return from the filter line. The line going to the lift pump remains full.

 

but did you eliminate the glow pugs as a problem by plugging it in, its the only way to do it cuz if it starts fine hot, plug it in over nite and try it.

 

I ordered some fuel line olives for it. They should be here tomorrow. I'm gonna put them in and try it. If that doesn't do it, I'm going to go the glow plug route.

 

glow plugs will not cause air bubbles in the fuel lines. that is either a bad lift pump, or the line between lift pump and sock in the tank sucking air.