New to Datsuns, working out the kinks on my '70 521 DD

[Parkinglotslider521]

whats up everybody, been lurking around and i finally have a few decent questions.I have looked around and cant find the answers to any of these questions, so if they have been answered I'll apologize ahead of time.

I have performed some minor maintenance, as the truck was sitting for a while, so its got new plugs, oil and filter, brake and clutch fluid replaced, etc. Stock Hitachi carb, disassembled, cleaned and reassembled. I already took the stock vac. actuator off the secondary and converted it to a mechanical secondary.

 

So my first issue is my carb adjustment. I just got out of the turbo DSM game, so carb's make me look stupid. no matter the engine temp, she runs like poop when the choke is open. If i keep it closed it will idle up, but it will also run like a top all the way thru the gears, minus the minor hiccup every now and then (plug wires next), but the second i open the choke, even if it has been running for an hour, the idle drops to normal, and it spits and sputters when the throttle gets touched. it also vapor locked (i think) tonight. acted like the battery was dead, didnt want to start, slow cranking. left and came back about 20 minutes later, and it started right up.

 

second i have a few wires and one vac. line that i haven't the slightest clue where they go to. The vac. line comes out of the base of the carb, and im assuming goes to the bung on the intake manifold, but they were both capped off.

There are two wires near the clutch/brake master cylinders, and they are both unplugged from where ever they go. I'll get oics up tomorrow (why are they called oics???) and make everything alot clearer.

[flatcat19]

Pic requests in 3, 2...

[wayno]

Welcome to Ratsun B)

I am assuming now that it is a L16 engine?

Is there a vacuum line on the distributor?

[Jayden71]

Pic requests in 3, 2...

 

NOW!!!! would be nice. Just sayin

 

 

 

 

 

 

 

 

 

 

 

 

Welcome :thumbup:

[Parkinglotslider521]

It is an l16, with factory (to my understanding) blue paint still on the block.

no vac line that i can see.

there is a little box with 2 wires coming out of it, mounted to the throttle that gets activated with throttle that is linked to timing advance from my understanding. i need to hook that up as well

[wayno]

It is an l16, with factory (to my understanding) blue paint still on the block.

no vac line that i can see.

there is a little box with 2 wires coming out of it, mounted to the throttle that gets activated with throttle that is linked to timing advance from my understanding. i need to hook that up as well

 

A line should come out of the lower part of the carb, and go to the dist. vacuum advance, I cannot tell you which outlet is the proper one though.

I don't know a lot about the dual points distributor, I have never actually seen one before, or maybe I should say if I have seen one, I didn't know I was looking at one.

What happens when you open the choke at higher rpms?

Are there any vacuum leaks?

[Parkinglotslider521]

it is dual points, which i thought they all had. but the wiring harness has the hookup for the throttle switch, and there are two wires running to the dist. besides the coil wire. The hard line coming from the carb was rusted and half gone, but it was pointing to the dizzy.

And even if im on the throttle at high rpm's, when i open the choke it falls flat on it's face. no vac leaks that i can find.

 

Would it be sacreligious to install my glowshift wideband left over from my talon???

[wayno]

it is dual points, which i thought they all had. but the wiring harness has the hookup for the throttle switch, and there are two wires running to the dist. besides the coil wire. The hard line coming from the carb was rusted and half gone, but it was pointing to the dizzy.

And even if im on the throttle at high rpm's it falls flat on it's face. no vac leaks that i can find.

 

Would it be sacreligious to install my glowshift wideband left over from my talon???

 

That would likely be the one that goes to the dist. vacuum advance.

I am not a fan of downdraft carbs, but I know that vacuum leaks are bad, hook up the dist. vacuum line.

[flatcat19]

Why are you pilling the choke while driving or warm?

 

You can convert your dizzy to run just the primary point.

Or better, go electronic. Way more reliable.

 

[konig209]

it is dual points, which i thought they all had. but the wiring harness has the hookup for the throttle switch, and there are two wires running to the dist. besides the coil wire. The hard line coming from the carb was rusted and half gone, but it was pointing to the dizzy.

And even if im on the throttle at high rpm's, when i open the choke it falls flat on it's face. no vac leaks that i can find.

 

Would it be sacreligious to install my glowshift wideband left over from my talon???

My $0.02 dual point will make your shit run like shit. I could no matter how hard and how well it was timed it missfires up the yin yang my personal oppinion is find a single point and wire it right or go e.i. Thats just me though cause my truck would not stop missfiring with the dual and wouldnt run well till i got the single from mark

[Parkinglotslider521]

OICS!!!

 

 

 

 

 

 

 

 

 

 

heres the 2 random wires near the brake cylinder.

 

 

and the dual points dizzy

 

and the throttle controlled switch (for the dizzy???)

[DanielC]

For emission reasons, your 521 truck had a dual point distributor. The second set of points are set 10 crankshaft degrees retarded.

The retarded set of points is used only when you are cruising, or lightly accelerating in third gear. If the throttle is closed in third gear, (idle) or WOT in third gear, the retarded set of points is not used.

There are several switches for this system. A neutral switch. A third gear switch. A clutch switch. A switch on the throttle pedal, for Idle. A switch on the carburetor for WOT. All these switches control a relay, that just puts the retarded set of points in parallel with the advanced set of points.

Your truck will run best if the timing stays advanced all the time. If you need all these switches hooked up to look stock, just set the retarded set of points in the distributor to open at the same time as the advanced set.

 

But reality is you would do far better getting a more modern matchbox distributor that came on later L-series engines.

[banzai510(hainz)]

olddatsuns.com (read everything on there)has wire diagrams. Make sure the right wires go to the right spot.Esp on the dial points set up.. if you get confused you can always disconnecto both wires and route one wire from the distributor. the one with the bigger condensor on the side. This will be your main points.

 

all else fails it OK to plug the vac line from the base of carb.

 

I dont see a vac canister on the distributor. I wonder if this is needed to keep it from over advancing? I just dont know on this one.

 

 

OK if you put the choke to off and the idle dies out and motor stops maybe the mixture screw at base of carb needs adajustment.

 

you charging???????? have a volt meter?

[Parkinglotslider521]

found out for sure im not charging. going to switch to a gm 1 wire i have laying around. it will charge, then it wont, then it will... over and over, at random. i think the voltage reg. is dieing.

[bilzbobaggins]

Whats the story with the dash?

[screamer510]

I think the dash is a replacement

Hehehe

 

Dan

[Tucson620]

Nah, I think the photo image of the dash is just flipped. Ya pretty sure.

 

If you can, definitely replace that dual points dizzy (and get appropriate coil, wires, etc.) My dual point dizzy "worked" but was really fussy. Electronic ignition made a big and immediate difference on smoothness and reliability. I also don't understand why you don't have a vacuum canister on yours for advance.

[banzai510(hainz)]

if volt reg is out the alternator will give you most like a overvolt condidtion.

a 521 alt is only like 40$

 

if the GM is a one wire does it have a internal volt reg on it? If so you need to jumper soem wires at the connector where the old volt reg plugs in to.

have you dont this? I bet not

 

You know what you doing?

[Parkinglotslider521]

yes i know what it will take to wire in the gm 1 wire, it's actually just a cable from bat. + to the post on the alt. I was the wiring guru at a local performance shop, Thor blessed me with electrical understanding (to an extent). wiring isnt really scary once you brake it down.

The previous owner began the rhd swap,and swapped the dash components. image isn't flipped, the steering column is still on the left. as soon as i can find a rhd steering box, the swap will get finished :devil:

The previous-previous owner was a mobile mechanic apparently, but not a very good one. lots of stuff on this truck was rigged, so i get to find all the bugs :thumbup: he probably removed the vac. advance canister.

[Parkinglotslider521]

Oh, can anyone point out the voltage regulator to a newb? i have 3 little black boxes that all look the same, and the jackhole "mobile mechanic" painted over the wires.

[thisismatt]

The volt reg should be to the left of the battery tucked up under in the fender well. None of your pics show it. It has a 6 wire plug.

 

Here is a helpful resource (doesn't show volt reg mounting, though): http://www.carpartsmanual.com/datsun520/Datsun520521Index.aspx

[Parkinglotslider521]

Found what's left of the voltage reg. Some dillweed chopped 4 of the wires off AT THE FUCKING PLUG so I can't even rewire it easily.they attached them together in 2 groups, to bypass the voltage regulator maybe? Dunno, but im saying forget the stock setup anyways. And the gm alternator i have isnt the simple 1 wire, it has a batt. Positive stud, and one plug with a control wire coming out. So i can wire it to kick on BELOW 1500 rpm's, which is where the simple 1 wire kicks on. SWEET!!

 

Also messed with the Carb, the mixture adjustment screw was only out 2 turns, now it's almost snug and it runs great, chirps 2nd, and doesn't sputter at all unless I punch it, let off for a second, then punch it again. Even then it only hesitates for a second.

[thisismatt]

Found what's left of the voltage reg. Some dillweed chopped 4 of the wires off AT THE FUCKING PLUG so I can't even rewire it easily.they attached them together in 2 groups, to bypass the voltage regulator maybe? Dunno, but im saying forget the stock setup anyways. And the gm alternator i have isnt the simple 1 wire, it has a batt. Positive stud, and one plug with a control wire coming out. So i can wire it to kick on BELOW 1500 rpm's, which is where the simple 1 wire kicks on. SWEET!!

 

Also messed with the Carb, the mixture adjustment screw was only out 2 turns, now it's almost snug and it runs great, chirps 2nd, and doesn't sputter at all unless I punch it, let off for a second, then punch it again. Even then it only hesitates for a second.

Sounds like someone already modified it for a internally regulated alternator. Would look something like this:

 

[Parkinglotslider521]

ok, i apologize to the former-former owner, who i will simply refer to as "Dillweed".

Dillweed did modify the harness for an internally regulated alternator. I do not like how alot of wires are run, but they are at least heat-shrinked. now i just need to know what alternator to get.

[thisismatt]

Take a look here for the Saturn alt swap: http://community.ratsun.net/topic/18218-how-to-install-a-saturn-alt/

 

I'm about to do this swap myself. I picked up a 97 alt off ebay for $25 shipped and I'm waiting on the alternator plug from another site (would have been nice to find it locally at a yard, but the only salvage yard near me sucks balls, so I end up having to order most parts). Another alternative is to just get an internally regulated alt from a newer nissan. I believe 720 trucks are a good option, or perhaps early 200sx.