Datura - zombie potion 620 build

[lowdatsun620]

Hey guys,

 

So this thread is for my new $500 beater/parts '77 620 build. For the next while, this thread will have a lot of overlap and reference to my other project SicSic620(http://community.ratsun.net/topic/15731-project-sic-sic-620/?p=1111255) as the two will be mashed together, intermingled, deconstructed, reconstructed and generally clusterfucked until Sic is finished so that I can have a driveable 620 in the mean time. I made it a separate thread because I will still be doing a lot of work on this truck that won't make it into Sic, and it may actually survive as it's own project afterwards. For all intents and purposes though, this truck is an organ donor.

 

The name Datura comes from a plant that Voodoo witch doctors (bokors) used in the 'zombie potion' they used to cause the trance state of their 'zombies'. This truck is 'reanimating' Sic from the dead (again) like a zombie, so it works. Also I like saying it 'Datjura' kind of like 'Gojira', Godzilla's real name. So Datzilla in Japanese. Lol.

 

So the story I know is I bought it off a guy and his roommate, who pulled it out of roommates boss's field after 7 years last week, seafoamed it, carb cleaned, got it going, but couldn't get brakes to work. E-brake worked and he "said" the brakes were kinda almost sorta working for them, they limped it home. DR wheel cylinder leaked. Tried to bleed the problem away for other three, no success. Didn't know about the load valve so I'm hoping that's the remaining issue. I brought it home last night, in a white knuckle thrill ride of a 5 mile drive who's highlights included a longish, steepish blind s-curve in mid 3rd gear dragging the e-brake and still picking up speed, a decent stretch of several lights on a two lane road in moderate traffic that involved a few stale yellows and a few one-tire locked, hard downshifting panic stops, and capped off with pulling into the driveway, two-handing the faded e-brake and a long 3 second slow stop, begging the truck to stop before I rear ended my Tundra. Disclaimer: DONT try that at home kids!

 

Anyways, I know how it goes around here so shut up, pics!

 

Hey, not bad for 500!

 

Couple dents, little surface rust, no biggie!

 

Okay, it might have cancer.

 

Okay, the cancer may have spread...

 

...a lot.

 

It's everywhere! (Pass. Rear cab corner)

 

This shits definitely terminal. (Drivers rear cab corner)

 

TER-MIN-AL (drivers footwell)

 

Seriously, I'm really not sure how the cab stays on the vehicle. (Drivers mid cab mount.)

 

The passenger footwell had some crap in it didn't feel like moving but it's much better, childproofed really. You can only get a few digits to the outside, rather than entire limbs.

 

Someone tried to perform reconstructive surgery in a back alley somewhere, patched the rotted fender top and bottom with what appears to be several pieces of gutter and roof flashing scraps, a few rivets and some bondo applied with a fork. Smart guy quit while he was ahead, decided sanding, or even finishing the bondo, really was just putting lipstick on a pig. Couldn't even find a second almost empty can of 'Fukit Closenuf' premium color match to paint the top side.

 

But it's got a pretty decent bench seat, just one rip. My old one had a bench back with two bucket bottoms and a low, crappy fibreboard panel in between that served zero purpose except to ensure I definitely couldn't convince any girl and her friend that it could almost comfortably seat 3, so this feels like the premium version to me.

 

Also has a really clean white headliner, something mine also didn't as it had a leaky aftermarket sunroof and no headliner. Classy!

 

Other observations so far:

Dash is cracked, windshield is perfect, front bumper has one decent dent but straighter than my chrome one, have to check behind to see if it's less 'peely' than mine. I also have a straight painted one anyways. Stereos busted, no tach, dash and lock knobs mostly missing, door panels in black in decent condition, good hood, solid but dented roof, chrome headlight bezels on grille all in place, one tail lens busted, one front signal cracked, all other lights good. All emissions components seem to be in place, a few vac lines disconnected need sorting out, doesn't seem the wiring has experienced too much fuckery.

 

Good enough for now. I worked on the brakes today, I'll post that later.

[lowdatsun620]

Oh yeah, this too.

 

[MicroMachinery]

May the Force be with you...

[datzenmike]

Throw that fender away, it's for the best.

[TENDRIL]

 

Someone tried to perform reconstructive surgery in a back alley somewhere, patched the rotted fender top and bottom with what appears to be several pieces of gutter and roof flashing scraps, a few rivets and some bondo applied with a fork. Smart guy quit while he was ahead, decided sanding, or even finishing the bondo, really was just putting lipstick on a pig. Couldn't even find a second almost empty can of 'Fukit Closenuf' premium color match to paint the top side.

 

 

 

this made my morning!!!  :rofl:  :rofl:  :rofl:

[datzenmike]

I removed my cab. Tipped it up on end to get at the floor.

[lowdatsun620]

Throw that fender away, it's for the best.

Swapping em for my green ones for now, there's no saving it.

 

I removed my cab. Tipped it up on end to get at the floor.

Yeah, this cab is getting replaced with Sic's for now, I just want to sort out the brakes and get it tuned up first, make sure it's worth the effort. I also have to finish prepping the underside of Sic's cab, and decide if I want to replace her floor pan first, which means getting the body drop done too. That pan is a little Swiss cheesy too, but compared to this one it's factory fresh, and it's body mounts are all spotless. I'll probably just paint it and swap it for now. I'll update that thread this eve.

[lowdatsun620]

So today:

 

Removed the passenger pinch weld... By hand lol

 

Along with half the bondo rocker panel.

 

The only half that was left.

 

And cranked the torsions all the way. On front bumps now.

 

Also realized it had no wiper arms, luckily my old ones were handy, so popped them on. I'd removed the springs so they didn't stress the arms while they were off, had to put them back. Didn't look at full contents of that bag, didn't realize there were 1" tabs for the inboard end of the spring, so fought to high hell with stretching springs all the way and mounting before realizing so didn't bother. Tensions not crazy tight, can still lift arms pretty easily, figure it'll wipe better, but maybe go through blades faster also.

 

Going to get u-bolts and drop blocks now, will probly wait till brakes are bled to install, for working room.

[lowdatsun620]

Couldn't find blocks today, frick. This towns all mall crawlers and bikes, almost nobody lowers trucks, even Lordco (our version of RockAuto) looked at me funny. Are lift blocks exactly the same? I feel like I must be able to find "lift blocks" here, every other truck is lifted.

[Grahem]

i have 3" 'lift' blocks on my lowered 78 620

[lowdatsun620]

Oh yeah, so yesterday I tore apart the drivers rear brake and replaced the leaking cylinder with one I pulled from Sic. It was pretty dirty and a little corroded but I brushed it off and pulled it apart. The seals looked fine and the bore was fairly smooth, but corroded in between the pistons. Didn't have anything I could really scrub it with but brake Kleen and ran a couple shop towels through the bore. Hopefully it will seal and last a while at least.

 

Pads were almost full, hardware looks relatively unused if not aged 7 years, just covered in a blanket of brake dust. Drivers was a little cleaner as the POs were tracing the leak. Here it was before I started, forgot to get an after. It's just cleaner lol.

 

I also had cleaned my old master up before picking the truck up just in case. Couldn't get the cylinder out of the bore but got it moving freely, felt smooth. This master was pretty gummy and corroded, worse than old one so decided to swap before bleeding entire system. My front reservoir cap was corroded and lock ring wouldn't move free of cap so swapped for a working one and cleaned it up.

Here's both.

 

Took old master off, looks like someone spilled brake fluid all over the power booster, paint all shrivelled and soft on bottom and had all this yellowish sugary stuff inside.

 

So I decided to swap it out too, but my '75 unit is probably 2" smaller than the '77 unit. It worked before, don't think anything else changed, except the NLSV, hopefully that doesn't cause a heavy pedal.

 

Finished reinstalling.

 

Bled MC front n rear today, no issue, started to bleed NLSV front, got a little fluid, then seemed like none, then a little on each pump, then started spitting out black fluid for a few pumps, then seemed to stop again. Storm rolled in and I was confused so we quit. It might have been because the bleed hose was like a candy cane going up from bleeder and curving down to catch can. the fluid seemed to sit at the peak of the arch, wouldn't really pulse with pedal as I expected. Either little to no fluid was pumping, or the fluid was running over the crest and down the tube so quickly it wouldn't actually pulse the meniscus. Can seemed slightly heavier, but wasn't positive. I've never bled brakes before. Gonna try again tomorrow and observe better, pump it either until clean fluid comes out, or I verify it's not pumping at all.

[lowdatsun620]

i have 3" 'lift' blocks on my lowered 78 620

Lol cool, is it angled? I figured they were the same, wasn't sure if pins would be on opposite sides, doesn't matter with straight block I guess, but angled maybe?

[MicroMachinery]

 

 

I wouldn't get my hopes up about that cylinder.. it looks pretty corroded. I've tried to reuse ones that looked a bit smoother than that, and the seals just couldn't hold the pressure. Ended up replacing with new. Way to be frugal, but brakes aren't something I'd try to cut corners on.

 

Not getting pressure to bleed the brakes out? I'd check every corner and connection to find out where it's going. Then check your MC to make sure that the fluid isn't bypassing the spool/plunger inside when you step on the pedal.

[lowdatsun620]

I wouldn't get my hopes up about that cylinder.. it looks pretty corroded. I've tried to reuse ones that looked a bit smoother than that, and the seals just couldn't hold the pressure. Ended up replacing with new. Way to be frugal, but brakes aren't something I'd try to cut corners on.

Right now I really just want to get it so I can actually rip around the block and assess any other issues, I'm planning on doing the swap to BJ and discs sooner than later, so don't wanna put bucks into replacing wheel cylinders.

 

Not getting pressure to bleed the brakes out? I'd check every corner and connection to find out where it's going. Then check your MC to make sure that the fluid isn't bypassing the spool/plunger inside when you step on the pedal.

Yeah, I'll have to check connections, fluid in reservoir dropped proportionally to the amount I saw, so I don't think it's leaking out anywhere.

How does the plunger remove from bore? I pulled out the circlip, brushed away all the corrosion I could, but plunger wouldn't pop out any further than the clip anyways.

Also I've heard "bench bleed" thrown around a few times for replacing MC. I just bled after install, but seemed to bleed ok, is there a special procedure needed to properly bleed the MC before installing on vehicle?

[lowdatsun620]

So tackled brakes again today. sometimes I don't get the expected response at the bleed valve, little to nothing, sometimes lots. Rears went smooth and centre and rear NLSV went well, finally started getting fresh fluid there. fronts and nslv front were odd. Sometimes fluid would overflow the rear circuit reservoir (front one) and the front circuit one would deplete, like they were transferring fluid, either within the master, or between the NLSV circuits, but I have no idea how the valve works. I want to say the circuits are still separate as that's why reservoirs are separated in the first place, so only one circuit will fail. That would narrow it to master, but I don't think it is, incoming fluid was dirty, so must have been coming through lines. transfer seemed to be happening only when I was getting odd response at bleed valve. I had zero brakes to start with, now that I've bled through everything in the manual recommended order, despite hiccups, I have some brakes. Seems like right rear is grabbing the most, but I spun the front drivers and it stopped with the pedal. Got friggin hot out so I quit there. I'm going to bleed everything again now that the rears vented a lot of air and hope it goes more predictably.

 

Also tried to diagnose a vacuum issue. POs had said they couldn't get it to idle until they pulled a vacuum line from the carb. Had disconnected hoses from air cleaner to: carb, vapour canister and the nut junction on the EGR that goes to anti-backfire valve. I reconnected them all and tried to start it, wouldn't fire. Disconnected one by one, still wouldn't start. Scratched my head looking at the engine and saw I'd knocked off the coil wire, derp.

Connected all back up and tried again. Started but idled very slow and rough, almost stalling, but not quite. Ran ok with pedal, but slightly rougher, and sputtered when letting off pedal. Not backfiring out the intake but after firing (?) out the exhaust. Pulled hoses off one by one. No response on carb, reconnected. Disconnected vapor can and idle picked up. Reconnected and idle dropped. Disconnected junction and idle also picked up. Reconnected and it dropped. Canister and junction lines connect at a T, and vac comes from junction, so same effect. Seemed any vac leak improved idle, so pulled small vac line from intake manifold to anti-backfire and idle improved slightly (smaller line), pulled brake booster vac from same spot on intake and idle went way up, but rougher. Decided this meant there wasn't an individual issue so much as the mixture just needed to be dialled in, so adjusted idle mixture and idle speed with junction vacuum leak plugged and it idles way smoother now at a decent speed. Both were way out of whack, a few turns each, settled at mixture about 1/4 turn out and speed 1-1/2 turns in.

 

However, it still pops n sputters when letting off the gas....

 

Also sounds like valve clearance needs to be adjusted, #1 intake or #2 exhaust I think.

[MikeRL411]

Search in the "Brakes" section.  There are many discussions of "the front brake master is draining into the rear" syndrome.  The answer for your model might just have already been found, and Datsun Mike probably provided the correct guidance! 

[Grahem]

I think there tapered, i will double check tomorrow if you like.

[lowdatsun620]

Search in the "Brakes" section.  There are many discussions of "the front brake master is draining into the rear" syndrome.  The answer for your model might just have already been found, and Datsun Mike probably provided the correct guidance!

 

Ok I'll dig around over there, I remember seeing some of that discussion but I didn't have the problem then, now I can't find it lol.

 

I think there tapered, i will double check tomorrow if you like.

Sure thanks.

[lowdatsun620]

Didn't have a buddy to hit brakes again, so did all this:

Set cold valve clearances, couple of exhaust were almost 50% out, most a thousandth or two.

Drained cooling system, replaced leaking heater hose, flushed and refilled coolant, replaced rad cap.

Ran engine degunker through, changed oil and filter.

Installed air filter, replaced fuel filter.

Vacuumed up interior, along with half the rotted passenger floorboard.

 

Runs smoother, sputters less on decel, or at least is muffled more by air filter. No longer sounds like a diesel from valves tapping. Should fine tune mixture again now that it is smoother. Quite pleased with tuning results so far considering this sat for 7 years, and has only had a couple short drives. Burns a bit of oil, especially when cold. Hoping oil flush and carb tune, plus a few more miles will clean up the cylinders a bit and improve that. 

 

One question, should i feel pulsing through the valve cover when engine is running and oil cap is off? I feel like that means a blown valve seal, and might be source of my burning oil. If i put my hand over it feels like a slight vacuum overall, but kinda pulsing both ways, soooo intake valve seal?

[lowdatsun620]

Here's a pic of the head with valve cover off when I was doing the valve clearance.

 

Here's a pic of my other head, which I took rockers and cam out of today.

 

I didn't clean that 2nd head with anything, just wiped oil off as I've worked on it. Oil was black, and I think pretty gasoliney from whacked carb and all the carbon, could gas in the oil have helped loosen gunk from head? Or was that thing cleaned recently? Gaskets seemed newish. Just so much carbon in the chambers, and really gunky outside too. Or alternatively, is the first one really dirty, all that crap is kinda baked on.

[5t341tH]

hey i have that same problem as you with the NLSV as well. Front bleeder comes out very little, if any at all. The center and rear ones bleed fine and clear, but the front would have dark fluid in there still. The front brakes bleed clean though. I was confused as you are and just left it as is. Brakes fine to me

[lowdatsun620]

hey i have that same problem as you with the NLSV as well. Front bleeder comes out very little, if any at all. The center and rear ones bleed fine and clear, but the front would have dark fluid in there still. The front brakes bleed clean though. I was confused as you are and just left it as is. Brakes fine to me

Interesting. My fronts bled similar to that. Still have to do them again, hope they will bleed clear now that the rest are fine.

[lowdatsun620]

Edited: wrong thread.

[ggzilla]

should i feel pulsing through the valve cover when engine is running and oil cap is off?

Definitely. If it doesnt pulse then your engine is bad. Other engine types don't do it.

[Grahem]

i think there flat from what i could see no jack at my house so i couldn't get under the truck.