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84 K20 "Ethel" Not an Sbc/NV4500/241C

Semi restoration of a 1984 K20 pickup. 5.3 LS, nv4500, np241c.
Overview Gallery Discussion
Gear it like you would a 305 powered truck. The 6.2 is governed to 3600 rpm...sustained r's in the 2500 range aren't out of the question, it's just a little loud. My old Jimmy I ran 4.56's and 39.5's with a SM 465. Freeway rpm's were 2700+ and we drove it 1200 miles to Moab and 1200 miles back to Vancouver. No problem as long as you're OK with not being able to have a conversation, or listen to the stereo, or ever have normal hearing again. :D
 
I don't have normal hearing now.. I believe 4:10 would be right in that rpm range too.
 
I've put mine in 3rd several times just to get an idea of different gearing. 37s and 4.56s make it say a 65 mph max type of truck. In overdrive its fine to 75 ish
 
That sounds reasonable..
My springs have 2 leafs.

I charged the batteries up, changed the oil and filter, put 7 qts of delo 15/40 back in.. It reads over full now... Thanks Internet.. But damn it's quieter when it's idling.
Checked the fuel filter and the leak I think is just the seals hardening on the filter itself so I'll replace that this week.. I need both radiator hoses, but first need to verify its not leaking water at the pump, it's coming from somewhere..
Reseated all the fuses and that gave me dash lights! But I still have no oil pressure reading and no glow plug light unless cranking hmm..
Alright I need some help detectives!

Ther is this hose coming off the injectior and is not plugged??
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This yellow and black wire goes into the harness???
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Here's the relay wiring.. Once I got the batteries re wired and cleaned up this is working as it should and the truck starts really easy now.
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I have several leaks at the injectors, I haven't tried to tighten the connection between the line and injector yet, is there an o ring or something I should be replacing?
I did test the glow plugs and they all lit up with my test light while cycling.

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I also discovered this green and blue connection that went under the truck and was cut off.. No idea but it does go into the cab where I was not able to trace it out due to no light.
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The injectors have a copper washer like a brake line under them.

The hoses leak alot too.

Do not get the Dorman hose kit for the injectors
 
The valve cover appears to also be covered in fuel. So I'd start with getting that filter housing happy. After that, I'd replace the rubber hoses on the overflow lines.

I don't know any of the wiring answers off the top of my head, but I do have an '84 6.2 Suburban. I'm willing to go inspect my wiring and share pictures, if that would be helpful.

And I'm pretty sure that overflow hose in the first picture isn't stock. Each injector is daisy-chained to the injector in front of it. The rearmost nipples are capped off. The front ones T into a hard line at the front of the block (which also receives overflow from the IP) which heads back to the tank. My truck was missing one of the caps, so I wound up taking an extra length of hose and connecting the two rearmost ports since I didn't have another cap. But your passenger-side injector appears to have its cap still installed. :thinking: Does it go directly to that rear injector? If not, it could be part of the windshield washer line that runs right through there... :dunno:
 
Yes please take some pics!
The injector line does plug into the last injector so that would make sense. I didnt realize that was a plug. both sides have this, and they do tie into the front of the motor by the inj pump.
Thanks again!
 
sreidmx said:
Yes please take some pics!
The injector line does plug into the last injector so that would make sense. I didnt realize that was a plug. both sides have this, and they do tie into the front of the motor by the inj pump.
Thanks again!
Click to expand...

Well...is the line actually plugged? If so, you're good to go. If it's open, and fuel is dribbling out, that is worth fixing. The plug should be a cap that fits right over the nipple, no line required. It looked like that's what the passenger side had in your picture (though it's behind the injector line, so I can't really see it clearly).
 
Ok...here are some wiring pictures. I solved at least one of the mysteries for ya. :)

The yellow wire is part of the harness going to the GP relay (looks like it's one connector on my truck, but 2 connectors on yours. :dunno:). Yellow wire is the furthest back wire (hard to see)

IMGP4069.JPG

At the relay, it breaks off.

IMGP4070.JPG

And heads over the top of the radiator...

IMGP4071.JPG

To arrive at the radiator water level sensor. I'll bet that it sagged down and got caught by the fan.

IMGP4073.JPG

You have an idiot light connected to this sensor. When functioning, it will light up for a test every time you turn the ignition on. I'm guessing that yours doesn't do this.

IMGP4077.JPG


sreidmx said:
I also discovered this green and blue connection that went under the truck and was cut off.. No idea but it does go into the cab where I was not able to trace it out due to no light.
Click to expand...

As for the blue/green wires, they head down into the engine valley at the rear of the block. 2 sets of wires head down there, one goes down the bell housing and disappears underneath, the other pair head around the engine to the TPS on the IP (if you even have one of those :dunno:).

IMGP4074.JPG


If yours are the ones the head down the bell housing, they should be going to the switch on the T-case lever (which controls the "4x4" light to the left of the "low coolant" light). Is this also broken on your truck? Your gremlins may be less important than you realized. :thinking:
 
Ok I saw the low coolant sensor wire but it was black which is why I got confused. and the 4x4 light would be nice to have but not needed.. so now to track down the GP light.. they work but the light might be out..
I have no TPS on my pump I think the only think is the cold start solenoid..

Another question, it smokes when it idles.. decent enough to see it. Im going to try to video it when its cold and when its warm..
 
sreidmx said:
Ok I saw the low coolant sensor wire but it was black which is why I got confused. and the 4x4 light would be nice to have but not needed.. so now to track down the GP light.. they work but the light might be out..
I have no TPS on my pump I think the only think is the cold start solenoid..

Another question, it smokes when it idles.. decent enough to see it. Im going to try to video it when its cold and when its warm..
Click to expand...

Black as in oil-covered? Or black as in it's a different wire? :dunno:

FWIW, my 1984 GP light is flaky. Some days it lights correctly, some days it doesn't. The relay is loud enough that I always know when it's working, so it hasn't been worth my headache to figure it out. If you bother tracking down the problem, I'd be curious to hear what the issue is.

I wondered about TPS. AFAIK, it's only used to control the EPR and EGR valves on C-code 1/2 trucks. So you shouldn't need it on your J-code.

As for smoke...welcome to the 6.2 club. Black smoke? Normal. Blue smoke? Burning oil (also fairly normal in small quantities). White "smoke?" Burning coolant. :doah: Green smoke? Yer rig just might be on fire (that means run away fast).
 
Yes the wire changed colors to black, somewhere in the harness, which I have not deloomed. I am suspecting the rats got the wiring for the light but Its going to require pulling the dash apart. What about the oil pressure? I dont know where on the engine that would be?? Id like to know what thats looking like.

The smoke is grey, almost black.. not blue and smells like diesel, it doesnt smell like oil is burning or water. It isnt alarming its just "there"
 
sreidmx said:
Yes the wire changed colors to black, somewhere in the harness, which I have not deloomed. I am suspecting the rats got the wiring for the light but Its going to require pulling the dash apart. What about the oil pressure? I dont know where on the engine that would be?? Id like to know what thats looking like.

The smoke is grey, almost black.. not blue and smells like diesel, it doesnt smell like oil is burning or water. It isnt alarming its just "there"
Click to expand...

Sounds like normal 6.2 smoke, nothing to worry about. You may find that the smoke level drops a bit after a bit, when you have finished burning up all the mouse nests and blowing all the dust out of it.

Are you saying that your green/blue wires are nibbled off under the truck or inside the cab? :dunno:

Oil pressure sensor is at the back, on the driver's side. In this general area, under the GP controller

IMGP4079.JPG


IMGP4078.JPG

The cylindrical can in the center is the GP controller. The 2 loose connectors used to control the EPR and EGR valves (no longer present). Oil pressure is the plug you can't see coming out the bottom of the harness. Wasn't able to lift the harness and keep myself from falling into the engine and work the camera at the same time. :haha:
 
Its actually not that bad, I only found those few wires that were eaten or cut. I was surprised, Ive seen rats do way more damage.. the only guess is they were just living in this but had access to food and water, my k5 had rats eating the harness like it was dinner, but that was stored in the dezert not the mountains like this truck..
 
one thing I just realized about these trucks and motors.. theyre insanely cheap to maintain.. wow... insane.
 
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