The saga so far:

Late summer coming back from a trip I had a major drop in power. Managed to limp it home but needed low range to get up any sort of hills.
Clear evidence of 2 burnt valve cover harnesses on the outside - 1 glow plug pin on each completely burnt up and serious scorching deformation of the adjacent injector pins.
While replacing the valve covers and harnesses one of the glow plugs (autolite put in by PO) broke inside. resulted in removing the head on passenger side only. I just let the fuel and oil galleries drain into the cylinders and cleaned it all up while I had the head off. Hydrolocking was not an issue.
Got the head off, cleaned up head and block , new gasket - all went well. barred it over a couple of times just to check and it was all good.
I never did remove ANY of the drain plugs in the head.
Topped up the HPOP with oil and I tried to fill the fuel bowl but there isn't any room for any fuel in there. Does this make sense?
Anyway, I have been trying to start it. I left the glow plugs out and cranked for a good 10 seconds (fuses pulled) or so several times over the course of an afternoon. installed the glow plugs, charged batts, cranked and I have only been able to get it to start to fire, but as soon as I release the key it dies on me. I should clarify that it never actually runs, it just coughs along with the starter cranking. some cylinders are firing but not enough to get it running.
I just checked the hpop and it is full up and the oil is much darker than the clean oil that I filled it with so I am assuming that the clean oil has made its way into the heads. This is good.
But why won't it run? It must be because of the fuel - right?
I have triple checked all my electrical connections and all is good - which does make sense because it does fire a bit.
I have searched and read a lot today and nothing stands out as a possible problem.
4 glow plugs are brand new berus, and the other 4 are older berus but they all ohm'd out at about .6 ohms (same as the new ones) so they are good. When I first turn the key on I hear the GP relay and ammeter ticks way over to the left, so the GPs are drawing the juice.

I'm open to any ideas/suggestions.

 

oh yeah - one more thing. There is an electrical harness right underneath the turbo (2 wires) and the wires come from the same harness as the injectors/glow plugs. I am 99% certain that mine was disconnected before I started the work (ie, it has been disconnected since before I got the truck, and the truck was running fine). I now have it plugged in. Any ideas what this harness does?

It is the one under the turbo in this pic

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That plug is for the EBPV. I would unplug it again since they have a tendancy to stick closed, leaving you way down on power.

Now.. How long have you actually cranked it? I would disable the injector electronics(unplug CPS or pull fuse #22 or unplug the UVCHs). You just want to be able to crank the engine without the injectors firing so they can fill with oil and fuel. Crank it this way probably two or three times in 10 second intervals, allowing the starter to cool for a minute between cranking. Once you've done that, plug the CPS back in or replace fuse 22 or plug the UVCH back in.. Or however you disabled the injectors. Try cranking it again, in 10 second intervals until it starts.

It sounds to me like you just need to get it primed up again. You've got a lot of air in the system that needs to be worked out.

 

Thanks a million. When I had the downpipe off it was open but I will disconnect it again now in case it has closed. I'll look into it afterwards to see if there is a problem with it. Right now I would just like to get the truck running.

I did do as you describe and crank off/on for quite a while with the injectors unplugged and glow plugs out. I did it by jumping the starter relay on the passenger fender. At that time the oil in the hpop did drop and I retopped up.

I wonder if I have low fuel pressure? If I understand the system correctly there is no fuel return line from the heads (at least I didn't see one when I removed the pass side head) and the pump puts a relatively constant 60psi to each head fuel gallery, then the electrical solenoid on each injector uses the hpop oil pressure to open the injector and fuel squirts out. If I have low fuel pressure there may not be enough injected to sustain combustion?

 

As suggested, the head is likely still full of air. The way I purge is to crank maybe 10-15 seconds, then loosen one of the oil rail plugs to vent the air. Then top off the HPOP and repeat until the air is purged and oil comes out when you crack the plug. Then try to start it. Might want to have a battery charger on hand too.

 

an update:
I went home at lunch time and gave it a try. I have a charger on the batts and they are nicely topped up.
I hit the key and it cranked over good and fast for about 6-7 seconds before anything registered on the oil gauge or any movement of the tach.
After that, as soon as I started cranking the oil press would register and the tach needle would move. Came close to starting but just got some coughing and smoking (white/grey). There was a definite aroma of diesel fuel in the smoke. Still no love.

 

hmmmm, I just read this:

Exhaust Backpressure Regulator, also EBP Regulator
Output. For quicker engine warm-up at cold temperatures. If the IAT is below 37�F (50�F on some models) and the EOT is below 140�F (168� on some models) the PCM sends a duty cycle signal to a solenoid which controls oil flow from the turbo pedestal. This causes a servo to close a valve at the turbo exhaust outlet. The PCM monitors the EBP input to determine if the EPR needs to be disabled to provide power for increased load, then reapplies the EPR as load demand decreases until EOT or IAT rises.

it mentions in there "solenoid which controls oil flow from the turbo pedestal"
if my EBP sensor was disconnected before all this, and now it is connected, is there a possibility that it is malfunctioning and preventing proper oil flow to the injectors and/or HPOP?

just rambling and throwing stuff out there.....

 

Not a likely problem. Many, MANY, of us run with the EBPV unplugged with no issues at all.

You likely just have air in the heads as was stated above. Pull fuse 22 as was stated above, crank it for 10 seconds, crack one of the oil gallery plugs to release the air, re-tighten, then repeat until you only get oil out of the plug and no air. The injectors will not fire correctly while running on air. You've got to get the air out of the system enough to let them fire. Even once you get it running it can take as much as 500 miles to get all the air completely out of the heads. Keep in mind that the oil in the head can be at up to 3000PSI, and at those pressures air compresses A LOT. At least a lot more than oil does....

 

Ok, I'll give it another shot this evening.
I'll remove the passenger side valve cover (the oil gallery plug is under there isn't it?) and do some cranking and cracking of that plug. Let's see where that takes us.

thanks to everyone for the input - it helps to have some guidance to go in the right direction

 

No, the plug is on the top of the oil rail gallery and can be accessed without pulling the VC. I will see if i can find a picture.

 

Here is one.


This picture has a HPX (high pressure crossover line) installed in place of two of the plugs. It is the stainless steel braided hose in the picture. The plugs just look like a hex head bolt about 9/16 in diameter or so.

 

thanks very much - greatly appreciated. Looking forward to posting tomm that the truck is running

 

I would also check to make sure all other electrical connections are plugged in. Things such as the IPR, the fuel bowl harness main connection(attached to passenger side of fuel bowl, large connector), etc.

It is normal for it to take several seconds before oil pressure registers on the gauge also...

 

Thanks again. Where does the other end of that MAP hose go? I recall putting it on the passenger side intake manifold but don't think I actually hooked it up at the other end. Would it be critical to running properly?

 

When you loosing the oil plugs be ready for a mess