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

The pedal probably isn't your issue if it works fine in open loop. I'm guessing you have an exhaust leak that causes the O2s to read false lean.

Also with the scanner you can command open or closed loop.
 
progress tnight...

i posted this on fb and not gonna clean it up.. hot out and exhausted...

For my car/truck guys read on...
others that dont like long posts...scroll...

People see us work on our projects and think everything goes right first time.. here ya go...

I tell my kids all the time, when something needs to be done...just do something each time, over time and it gets done. Also nothing goes as planned...
Now truck is running again, need o2 bung put in passenger collector for a start...drivers side is ok where it is at for now. I have an issue when truck goes into closed loop. stumbles and hptuners data someone said right o2 not reading right and causing 42% more fuel discharged...

so do something...
3 collector bolts removed with no issue...
took a break...
all nuts for header came out..no way!
then 2 bolts....
it is disconnected...
took break...
tried getting it out and nope, studs too long. Think i dropped engine in with headers on. Next time yank studs and use bolts...

put 3 nuts back on to bolt header to block...
went and grabbed angle grinder with cutoff wheel... got front one cut but too big for rest...
dremel didnt fair well and broke cutoff wheel...
used drill with a "ripping" bit... did what i could...
removed nuts and still couldnt get it out...
decided to remove axle side of front driveshaft...
5 minutes struggling with header came out!

put it back in, in seconds to check something....

now it is out but will have to put it back in for Bryan to mark where o2 bung should go...

passenger side has a flex exhaust which can leak and is wft past collector where drivers side o2 is just inches away...
hopefully my problem.
more to come...

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ok fam.. I really need to know your thoughts... I am torn...

i am thinking of cutting this out in vinyl on wifes cricut for fender badges...
white will be white and black will be my truck blue...

RootBreakerEmblem.png
 
Ya I had no idea your passenger side O2 wasn't in the header collector. That would explain your terrible readings
 
I had it running, took passenger side header off and had an o2 bung put in. Put the header back in and the truck wouldn't even start it would just click. Went and got two batteries from a buddy and it clicked a lot faster but it still wouldn't start. So I've left it alone for months and now I just put two new Deka batteries in it and boom first crank started right up. Sounds like garbage however it's probably the year old stale gas. But back at it truck is running so I can't wait to get somewhere with it.
 
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i step forward, 3 backwards...
posted my tune and log on hp tuners forums and one guy was nice enough to get my tune trimmed to be more drivable. I had to spend the day buttoning up the exhaust, wires, stuff... but i did drive it with current tune and logged it, then I downloaded the custom tune, bought the credits and wrote to my ecu... seemed better off the bat. like it was drivable. Backed out of driveway, went around the corner, then puked all the power steering fluid out!!! UGHHHH... so now i have to figure out why my power steering is dead. dont see a cut or break in hoses...

follow it here:

2002 8.1L - Recommended settings?

I posted in the wrong area (Gen 5) as this is a Gen VII but I see now... 2002.. go by year so my apologies... 4y ago I sent my harness to someone and for an extra $100 he did a "Hot Tune"... No clue what that was but also the following was done: * Auto to Manual * Torque Management...
forum.hptuners.com

most people expect to get paid for this, and i might pay a local guy to tune the truck but for now want to check this out and see where I can get with his help.
 
I havent looked yetbut I was just thinkin. I think the ps pump I put on was for a 5 3L... Would that have a 3rd line for powerboost? I know sometimes autozone sells pumps with plastic plugs pushed in and painted over. Wonder if I pushed one out...hope to take apart tmorrow.
 
I know the people have asked about how to do the Jeep steering shaft upgrade. I have had one in my truck for over 10 years. It's a great upgrade it gets rid of the rag joint and it has universals at both ends. I did have to put a v notch up in the column side. But the other side just slid right on and is a perfect match for where the rag joint went. My gearbox when which made me have to disconnect everything and when I did I realized that my Jeep steering shaft no longer collapsed and was rusted shut from all the mudding I've done. I went to my buddy's shop and we tried banging it apart and we couldn't get it and he said why don't you just look on Amazon. So I did and guess what I found one for 60 bucks right to my door within the next day. It works great it looks good it even has a rubber boot where the slipping goes and was a direct fit. So if you're looking for an easy solution here you go. Under the hood is still a mess of I apologize for how crappy it looks but the 8.1 l upgrade is done and it is running however I need to get it tuned and then straighten up all the wiring.


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It feels great to work on the truck it really does. Not only did I get the steering rehooked up and I should be able to take it out tomorrow, I also have been working with a local company who are great at getting keys made for a truck box. That truck box is now bolted down over top of the hole in the bed that I had a $15,000 lb Ramsey Patriot winch mounted to. So for now I can lock up my tow straps come alongs and stuff. I think it looks good I'm glad to get back working on the truck.

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Felt great but tiring of this ..



While knowing it ran, would fire it up to just run a bit... Started taking longer to start.

Now I cant get it started.

Can hptuners tell me if crank sensor or cam sensor is bad?

Tmorrow I plan on pulling fuel line (hear pump) and make sure have fuel... I expect it to...

Then pull a plug and check spark...
What else to check?

Silly thing is you always look at what was last thing you did... I put plastic envine cover on so will remove and make sure all wires look ok.

Havent done anything else.

I did have an issue with harness huy did a hot tune. Well 30% throttle was 100%... Guy on hotuners tweaked tune.. bit hard to start but 2 min would and throttle better .. havent ran truck to log.
Well since wont run, wrote old hotvtune that always fire up on 3rd crank.

So...ecu seems ok/powered....

Drive by wire too
 
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