Help me

[Chevylouise7]

So I have a 1982 6.2 diesel in my 1978 3plus3 4x4. And I got pump issues. I’m using a 92 6.2 electric lift pump and a Cummins filter set up.
I have went and got another injection pump that I was told was rebuilt and never used. It looks that the man was telling the truth.
My problem is still the same as my previous pump. I cannot get fuel to the injectors. I’ve tried everything. 9-10 psi of fuel pressure going into the pump after the filter. No leaks anywhere. Fuel is coming out the return great and no air in it. I’ve pulled the glow plugs and turned it over with brand new batteries and still nothing coming out at the injectors.
I’m really getting frustrated. Everybody tells me the same stuff that I have already tried several times. I even switched the fuel cut off solinoid from my previous pump to see if changed anything but unfortunately not.
If the fuel is coming out the return then the pump is taking fuel in so I’m very confused.
Appreciate any help guys. Thanks ☺️

[DmaxMaverick]

An air-locked pump can take quite a bit of cranking to get it up to pressure. The inlet and return fuel is the low pressure side. The injection pump has an internal transfer pump that moves fuel to the high pressure side and to the plungers. The plungers then have to push fuel to the injectors, while pushing out all the air. That air cushion hinders the process, as the injectors won't "pop" until they reach their pop pressure. You can lessen the cranking time it takes to get the system primed by loosening most/some of the injector lines (about 1/2 turn) at the fuel injectors. While cranking, you should see some fuel weeping from the lines/nuts. Let a little bit flow, then tighten them. If you have the glow plugs out, it really helps during the process with faster cranking speed, which also reduces the stress on the starting system. Once you have fuel weeping from the lines, it should be bled enough to get some fuel through the injectors. Keep your batteries well charged and don't lean on the starter for too long, and give it a rest to cool between attempts. Once you get fuel mist from a couple glow plug holes, it should start after (good) glow plugs are replaced. Don't be tempted with starting fluid (ether), as it can cause serious damage with a working glow plug system.

[Chevylouise7]

Thanks for the reply. I will continue to keep cranking the motor over in interval so I don’t damage the starter.
I have already wore the Barrie’s down twice and they are charging now. It must be an airlock as you said
is it common to have to crank it over for hours( in total) to bleed the pump
I’m slowly learning more everyday about these motors.

[DmaxMaverick]

It shouldn't take "hours", at all. A dozen 20 second cycles is the most I've seen. It sure seemed like hours, though. If you're getting (bubble-free) fuel out of the return, fuel is getting into the pump, so the supply end is doing its part. The pump will draw fuel if it's primed, even if the lift pump fails, as long as it isn't too restricted. If you don't get fuel weeping from the injector line nuts, suspect the pump itself isn't actually pumping to the injectors. Are you certain it is Diesel fuel the pump is pumping? Is it properly treated for the climate you're operating, if necessary?

Perhaps a little background on the original problem (that repeats with a "new" pump) may be helpful. Maybe we're chasing the wrong gremlin?

[Chevylouise7]

I’ve done a lot more attempts than 20 times. The original pump
stopped delivering fuel as well. I bought this one from a man that
said he had it rebuilt then never needed it. 250 dollars I paid and it was
clearing cleaned up and had fresh paint marks on a few of the bolts/nuts
I think a problem with the pump is what I might be dealing with
the motor came from an 82 originally. I now have two 82 motors
I’ve had a pump go before and it was relatively easy to get running
would you recommend getting the pump rebuilt (1200 dollars here) or
checked first which is 400 dollars. Only one shop in lower BC that will
rebuild them sadly. Bd diesel doesn’t do it anymore
thanks so much for the help ������

[Chevylouise7]

The original pump stopped fuel during the summer.
I also converted the truck to standard if that changes anything?
i dont have the two bolt electrical piece on the side either.

[DmaxMaverick]

Converting the truck to a manual tranny will not keep it from running, in any case.

I think you should try loosening the injector line nuts to see if you can get fuel through the lines. If it doesn't, the pump is not pumping. It's as simple as that. Could be a(nother) bad pump. Stranger things have happened.

[JohnC]

Are you holding the throttle wide open while cranking? At idle it could take days...

[Chevylouise7]

I believe you have figured out my problem, another bad
pump. I was using a jump wire to run the starter so I could watch for fuel.
Nothing coming to the injector lines. I loosened them and still
nothing. Looks like I will be getting a rebuild unfortunately
Luckily I have other things to finish up doing on the truck while I wait for it to be
done.
You have been very helpful and I appreciate it ☺️

[Yukon6.2]

I wouldn't be convinced it is the pump
Sounds like the issue from before is still there.
Did you have a reason to suspect the 1st pump?Other that it wouldn't start.Where there running issues,starting issues befor the pump change?
I have heard that a pump going bad will take a long time to actually quit working.
I would take a look at the shutoff solenoid,your new pump may have a 24V one.If the shut off was bad on your old pump then you will be chasing things that aren't there.
I have bought a few New in box pumps off ebay with 24v shutoffs,there were lots of military take offs on the bay for years buddy may have got one of those rebuilt and it still has the 24v shutoff.

[Chevylouise7]

The previous pump just died one day and I had to tow the truck home and
never could get fuel to come out of it. I actually tried three different shut off
solinoid a just to sure and it still has the same issue. I don’t want to give up but
feeling like defeated lol. I really hope I don’t have to pay for a rebuild but I’m not confident in used
pumps anymore
can even a small amount of air stop the pump from working
I have no visible leaks but I might put all new lines on before I give up ������

[JohnC]

Maybe a dumb question, but, are you sure the injection pump is turning? Are you sure the shutoff solenoid is getting power? Have you confused the shutoff solenoid with the HPCA solenoid? If you have fuel to the pump and the pump is turning, then I would be surprised if you have two bad pumps with the same problem. Try loosening one or two lines at the pump, floor the throttle, and crank.

[sctrailrider]

I would suspect the key way on the gear has broken and not turning the shaft...

[DmaxMaverick]

If you need to confirm that the pump is rotating, remove the cover and watch as you turn the crank by hand. I suspect that isn't the problem, as it is so unlikely with 2 pumps, back to back. However, used pumps are used pumps, regardless what the seller has to say about them. Also, you should be able to source a reman pump with warranty from a reputable supplier for a lot less than twelve hundred bucks. Rockauto lists one for $519.

[Robyn]

Ahhhhh

Just a thought.....
Unplug the LARGE PINK WIRE from the injection pump....
Turn the key to on and check the voltage at the pink wire.
Should show battery voltage.

The fact that the truck just suddenly quit make me suspicious of a loss of voltage to the IP.

Did you check the fuses......It would be rather sad to chase the wind here and spend more $$$$$ and then find a blown fuse.

The other possibility is a failed ignition switch..... and this can happen.

Grab your trusty VOM and make sure you have a good solid 12V to the pink wire.

OK
Looking at your original post...I see that the truck was not originally a diesel.

Where does the power feed for the IP come from ?????
Are you using the feed for the original ignition coil ????

FUSE BLOWN ?????
Here is a piccy of the fuse block

Check the IGN 20A fuse......

The IP should make an audible CLICK when the key is turned on.

What may have happened is the original shut off solenoid shorted and failed....blew the fuse....?????

Good luck

[DmaxMaverick]

Good fuel flow out the return suggests the fuel solenoid is opening, or is open by whatever means, and fuel is available for a good pump to push fuel to the injectors. This sounds like it's air-locked. As John suggested, WOT during cranking helps speed it along.

[Robyn]

My experience with these critters during a "Dry pump" startup with glow plugs out....has been 15-30 seconds and they will be blowing fuel out the plug holes.

Never had one take more than 30 seconds.....

The fact that this is a "Franken truck" the wiring makes me question.....

Only takes a second to check the supply voltage to the solenoid...

Why did the original setup just fail and stop running....?????

Before the fella spends any more $$$$ I would like to see him check the power source....

Would suck to find out it was just a blown fuse....

Or as mentioned....the new IP is a MIL pump with a 24 volt solenoid....

[More Power]

The previous pump just died one day...clip...

It's rare for a mechanical DB2 fuel injection pump to "just die". Generally, they give up slowly over time - thousands of miles.

To eliminate a timing/valve train issue, remove the air cleaner (assuming this is a non-turbo engine) then do:

1- Plug in the engine block heater for 4 hours before attempting to start.

2- Ensure the glow plugs are working. The 4 hour block heater usage should help it start even without glow plugs, but none the less....

3- Remove the air cleaner/filter, then dribble an evenly distributed tablespoon of clean diesel fuel in the intake runners leading to each cylinder (1/8th tablespoon for each cylinder).

4- Let the glow plugs complete a full cycle, then crank the engine. If the engine's valve timing is OK, the raw diesel fuel should allow the engine to begin to fire... roughly. Do this step 2-3 more times if you need to. The rough running will allow the engine to spin much-much faster than it will on the starter alone, which will help to quickly clear an airlock.

On the other hand, if the engine won't fire on the raw diesel fuel dribbled into the intake manifold, your engine may have timing problems. This sort of problem (solving an airlock) is discussed in The 6.2L/6.5L Troubleshooting & Repair Guide (https://www.thedieselpage.com/t&rguide.htm)

Good luck,

Jim

[Robyn]

Do not be tempted to use starting fluid.

Severe damage can/will result.

[mshawnm109r]

The nipple on top of the injection pump for the return was my problem after putting the tank and replacing the lines to the tank, the ip was new so that wasn’t the problem but the return check valve even through it seemed clear and I could see through it , it needed more pressure than the pump to open it. Took a Allen wrench and punched it out of there and then blew it out. I installed it back on an put there,….. it fired right up. Hit me back if you need more help and I’ll walk you through it