'78 K20 - RootBreaker from 1990 - nov 2025 8.1L not runnin

[runamok151]

Didn't you just swap that motor in? Must be a Jersey thing. hahaha

 

[sweetk30]

north east thing .

 

[RootBreaker]

What's all that brown stuff????????????

View attachment 371532

metal flakeage from virginia salts...

 

[RootBreaker]

after all bugs worked out and its runnin good.. in 1y-2y will pill and total overhaul.. or if i can find an 8.8L. direct drop in

 

[RootBreaker]

ok fuel system mostly done..
high pressure pump in tank...
couldnt get wrenches in to tighten an6.. may have to buy some harbor freights... cut short and also grind thickness....


lines ran...




hopefully they hold...

 

[mrk5]

I have return line on mine that's stainless braided with hose clamps, and I haven't had a problem on my 60psi system. Granted return line pressure is lower, but I think you'll be okay.

 

[RootBreaker]

I have return line on mine that's stainless braided with hose clamps, and I haven't had a problem on my 60psi system. Granted return line pressure is lower, but I think you'll be okay.

on supply line i put 2 clamps... on return just 1.
next is to start on wiring, then i can get power to it and see if leaks. will need to make sure its ok as it seems these an6 fittings are above where headder collector will be ...

 

[mrk5]

I do have single hose clamps on the supply line off the sender as well as the tank selector valve, but those are rubber EFI hoses.

 

[RootBreaker]

ok harness laying under the hood!!!!
everything connected except

MAF- I assume connects on air in tube?

vss - ???? does this go to trans? what do I do with this?

crank shaft sensor wire not plugging in and behind engine so tough...
did guy put wrong plug on it?

 

[ZooMad75]

That connector matches the image I have in the manual for the ckp sensor in the he connector end view section.

 

[RootBreaker]

That connector matches the image I have in the manual for the ckp sensor in the he connector end view section.

got a partial pic.. i think its totally different from what i see...

 

[ZooMad75]

got a partial pic.. i think its totally different from what i see...

View attachment 375569

Umm, that's the oil pressure sender. Crank sensor is just below that and if I remember right the connector comes in from the side and not the top.

 

[RootBreaker]

Umm, that's the oil pressure sender. Crank sensor is just below that and if I remember right the connector comes in from the side and not the top.

bwaahhahahaa I hope your right....lol that would b awesome...

 

[ZooMad75]

bwaahhahahaa I hope your right....lol that would b awesome...

I'm pretty confident I am. There's only one terminal on the oil pressure sensor you pictured, not three that the crank sensor has. The shape and size of the sensor is the other dead giveaway.

 

[Blue85]

Crank is yellow, oil is red. Orientation of crank sensor connector may be 90 degrees different.

 

[Blue85]

Here's the chart I made while doing my swap. A couple of the commctors are different for 03+, like the oil pressure sender.

 

[RootBreaker]

View attachment 375648Crank is yellow, oil is red. Orientation of crank sensor connector may be 90 degrees different.

thx.. yeah im good there...
finally got it last night lol...
3in body lift hrlped. did it from under the truck.

Here's the chart I made while doing my swap. A couple of the commctors are different for 03+, like the oil pressure sender.View attachment 375650

Thats cool!

so I have wrenched on my truck since 89 and did things b4 internet...like body swaps taking c10 diesel cab, swapping all wires and converting cab to manual...
if I have the parts, I can do it. If it worked and I know say alternator is bad...I can replace it.
Internet is making it easier and easier...
When I am done, I will have a full doc to share..from start to finish for dummies like me...lol

I still have questions and appreciate all the help.

like... obd plug... guy put label on green wire from ecu that says obd... then on obd plug, different color...says obd...
so under hood and under dash diff colors?

 

[RootBreaker]

I am stoked...got a mess of wires done!!!!! getting there.

Grounds ran, stand alone harness mounted and relays mounted. Wire ran for harness power to batt...



now for questions...

pink wire, 2nd from bottom on right is switched 12v. Where is a good spot?

I have to connect battery to starter big lug....
My old setup had another wire on big lug and one on small... still same?




gonna map out what wires i got where then remove them from harness...that are not needed...


at MMA right now for my kid... so took these 2 in jeep...



All black because I bought ez-Wiring 21 in black. Big mistake...will never do that again cuz when people say green is temp sensor...im like..crap!!!

gonna put obdii through stock harness too....


im stoked cuz once i get starter connected and switched power...I can fire it up...or try...
albeit no MAF or o2 sendors so will be rough im guessing.

 

[RootBreaker]

stupid stuff... oil, filter... vacuum barb on intake for break booster. that much closer!!!!

 

[RootBreaker]

More silliness...

Getting so close... MAF and intake tube on, alternator charge wire connected...albeit AZ didnt have it in red so shrink tube..lol..
next up ...2 o2 bungs to weld to headers, connect clutch cyliner then turn key!!!!

Gotta route wires when i get her going...