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520 came home to Oregon and brought me with it


XXL

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Relocated to Eugene, Oregon last week... following SO's job. My 520 is my daily driver (though I don't get out a whole lot), and the hills in south end of town where we now live are killers. I've had a slight miss at idle for a while, but didn't have the energy to chase it down. Now a good tune-up is going to be a necessity. May just be a weak plug or bad plug wire... but I would have expected if either of those were breaking down, it'd be worse at speed, but I drove to Cottage Grove and back yesterday and it ran down the highway at 68-ish fine. Any suggestions on top-notch shops around here that could take a look at it? I also have the beginnings of what sounds like an exhaust leak... maybe at the downpipe connection, and rear brake shoes are due for replacement and adjustment, I have a stash of spare parts for most of that stuff, but my garage is stacked to the ceiling after the move... our home goods just arrived a couple of days ago and movers just piled everything without paying attention. Even after  get it all sorted out, I'm old and crusty and have limited ability to climb around cars to work on them like I used to.

 

Any pointers are appreciated.

 

 

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I think banzai510 appears to be having a bad day as your not the first one he has told to sell it.

 

What engine you have in it?

 

Well I would say do a tune-up first and check/adjust the valves, also an exhaust leak can sound like a miss.

Edited by wayno
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3 minutes ago, wayno said:

I think banzai510 appears to be having a bad day as your not the first one he has told to sell it.

 

What engine you have in it?

 

Well I would say do a tune-up first and check/adjust the valves.

 

J13. I just found one of my spares bins, so I'm going to throw plugs, wires, cap, and rotor at it (it's got a Pertronix II, so no points), check timing, etc., and see if that gets me anywhere.  I think I've got a spare valve cover gasket in my other spares bin for setting valves (I've got 25 or so of those giant black bins with yellow lids from Costco for all my car crap, but the garage is packed to the gills, so finding the right bin is a project in itself). Are the lifters solid? And if so, any idea on what to set hot lash to? 

 

 

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My Chilton's manual says both intake/exhaust valves are set at .014, it doesn't say cold or hot but I suspect hot.

The ignition timing is 8 BTDC@600rpms, but it says some early models(1965/early 1966 more than likely) were set at 15 BTDC@600rpms.

Suggested spark plugs are NGKBP-6E gap is .028-.032

Edited by wayno
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9 minutes ago, wayno said:

My Chilton's manual says both intake/exhaust valves are set at .014, it doesn't say cold or hot but I suspect hot.

The ignition timing is 8 BTDC@600rpms, but it says some early models(1965/early 1966 more than likely) were set at 15 BTDC@600rpms.

Suggested spark plugs are NGKBP-6E gap is .028-.032

 

Thanks for the specs! I've got Autolite 405's in it now (they're a couple of years old), and a fresh set of the same in my spares. I seem to recall that Pertronix tech suggested a .035 gap, but I'll call them to confirm. My 520 is a May 1968 build, and 8° BTDC rings a bell from the last time I set it. I wonder which moving box my timing light is in 😨 

 

 

 

 

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Theres actually quit a few datsun folks in Eugene area. I go up there to hang once in a while. The dont visit the site much. You will have a better chance on FB Datsun forums

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Im just saying Top Notch shop is most likely going to be you and maybesome of us on here.

Shop don't like old vehicles unless that is thereonly business and they think they got you over a barrel.

New shops see a J motor they might freak.out .A British car shop might be better as its really a brit motor. and SAE sizes.

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2 hours ago, Farmer said:

You will have a better chance on FB Datsun forums

 

Thanks. I don't do FB, so I'll have to hunt them out by other means. 

 

 

1 hour ago, banzai510(hainz) said:

Im just saying Top Notch shop is most likely going to be you and maybesome of us on here.

 

Honestly, I was hoping for the latter... an enthusiast board member who loves working on stuff, who I could cajole with beer and cash (and 'wonderful' company... aka, "get out of the way, old man"). And my definition of "top notch shop" is probably unrealistic in the 21st century-- a place that doesn't rely on a CANBus plug-in to tell them what part to swap, who knows what a carburetor is, etc... AND... who is an honest broker (I have no desire to be over a barrel, for sure!).

 

I have a lifetime of skills to apply to the problem, but I am old and crusty, and have a ton of health issues that keep me from crawling around on a car. Swapping plugs, etc., is about my physical limit these days. 

 

Thanks for the comments.

 

 

Edited by XXL
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Datsuns came with and are built around using NGK plugs. Other makes won't be exactly right for heat range. I would get the ones for a J13 engine.

 

As mentioned above.....

On 12/5/2019 at 9:38 PM, wayno said:

My Chilton's manual says both intake/exhaust valves are set at .014, it doesn't say cold or hot but I suspect hot.

The ignition timing is 8 BTDC@600rpms, but it says some early models(1965/early 1966 more than likely) were set at 15 BTDC@600rpms.

Suggested spark plugs are NGKBP-6E gap is .028-.032

 

Where did you move from??? A change in altitude can affect the idle. Lower altitude is denser air so needs to be slightly richer. Try turning the idle mix screw out. You'll notice that the idle drops off in quality as you turn it out and also if you turn it in. There's about half a turn where the idle smooths out. Find the middle of the smooth spot and then turn the mix screw out just slightly richer.

 

Idle mix is just that. It adjusts the idle and just slightly above but does not do anything for driving around.

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11 minutes ago, datzenmike said:

Where did you move from??? A change in altitude can affect the idle. Lower altitude is denser air so needs to be slightly richer. Try turning the idle mix screw out. You'll notice that the idle drops off in quality as you turn it out and also if you turn it in. There's about half a turn where the idle smooths out. Find the middle of the smooth spot and then turn the mix screw out just slightly richer.

 

Idle mix is just that. It adjusts the idle and just slightly above but does not do anything for driving around.

 

 

Central TX. No altitude differences, but it's a helluva lot ranier here (though humidity there is regularly 80%... it's just muggy instead of actual raindrops like here). Also, as mentioned in my OP, the miss at idle isn't new. It's only become a bigger issue now because of the 1st and 2nd gear hill crawls in my area. Here's part of one of the hills in my neighborhood. I took it because of the absurd wheelchair ramp they just installed... we've nicknamed it "the suicide ramp." The picture doesn't do it justice. My SO, who is a very fit hiker says she steps onto street to walk that part when she's doing her daily neighborhood walk because the ramp is impossible to scale. I hope there are no wheelchair bound folks in the neighborhood who were in need of a usable ramp. BTW, that hill gets steeper (and curvier) to the right of frame. 

 

49182559913_ee0068fa64_c.jpg

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Well I find that at a 600RPM  idle there is only 5 sparks per second. Enough to say 1,2,3,4,5 fast enough in a second. If one misfires 20% of what keeps the engine turning is missing and is very noticeable.

 

Perhaps distributor cap rotor or plug wires? Every year or so I remove the wires and wipe them down with WD-40 to clean them of that blackish looking stuff that gets on all engine parts. It makes them clean and blue. I rub a smear of dielectric grease on the end contacts and the nipples before attaching to the plugs or the distributor cap. This seals them completely from the damp. I take particular care on the coil as I had a just off idle miss that lasted a couple of years. Eventually it got bad enough to find that it was a small crack or 'carbon track' in the plastic of the coil. The spark had found a short cut to the negative terminal and burned a path.... or it was a fine crack, it's really hard to tell. I had a spare coil and when replaced it was gone. 

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Small update for anyone interested--

 

Replaced plugs (I misstated re the ones that were in there already. They were NGK's, and I had gapped them at .035 (I found my old call notes from Pertronix tech support on the gap number). They look decent enough... no telltale tuning issues seen in the plugs). Here are a couple of pics-- 

 

49185633467_b55f960fd8_b.jpg

 

img%5D 

 

 

Rotor and cap looked fine...

 

49185436036_746c7b35f8_b.jpg 

 

49185633237_cfba5bbf35_c.jpg 

 

But... I couldn't swap wires because the _2_ sets I ordered from Rockauto are WRONG! Of course, I did the online return form and after answering all the standard questions, it tells me... nope, "manufacturer says those are correct." Well, Manufacturer... if you think these fit a J13, you are an idiot. Feel free to fly out and show me how these 11" long wires will reach the 14-20" needed to make it from the cap to the plugs. Anyway. Going to have to look for some wires that actually fit. Here is the part I bought. I've bought wires from Rock before and didn't have any issues. This part number is no bueno, so don't waste your time...

 

49185436096_5653f831dc_c.jpg

 

 

Bad news is that new plugs, rotor, and cap didn't fix anything... so I'm still looking for the problem.  Next up, find some plug wires. And if that doesn't clean up the issue, swap coils. 

 

 

 

 

 

 

 

 

 

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That cap is the nice copper contact one so don’t throw it away it’s still good.

I do a Mexican tune up by reconfigure up the motor and putting a rag over the top to suck up any crude in the carb.Do this while spraying carb cleaner.

If you have a Pertronix make sure it’s hooked up to 12volt.A lot of people hook it up on the down side of the ballast resistor.Im not a 520 expert so I don’t know if it has a ballast or resistive wire setup

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20 hours ago, banzai510(hainz) said:

That cap is the nice copper contact one so don’t throw it away it’s still good.

I do a Mexican tune up by reconfigure up the motor and putting a rag over the top to suck up any crude in the carb.Do this while spraying carb cleaner.

If you have a Pertronix make sure it’s hooked up to 12volt.A lot of people hook it up on the down side of the ballast resistor.Im not a 520 expert so I don’t know if it has a ballast or resistive wire setup

 

Yep. Already done. I do tend to hoard spares, even used ones. Also, I've got 2 more of those same caps new in box (in addition to the one I just installed). I even have several sets of front brake shoes..l and I've been running a @mklotz70 disc conversion for 5 years or so. I think that is the definition of hoarding... multiple sets of parts I don't even need. 😲

 

Also, Pertronix has been there for 5-6 years, and it's using a 3 ohm coil without ballast as recommended by Pertronix. Full 12v at terminal. Only trick you have to consider with this setup is to not leave key in ON position (when engine not running) for extended periods... and I don't.

 

 

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Have you checked the valve adjustment yet?

I had a valve get too tight on my L block and the engine started missing, I think it was an exhaust valve as it wasn't back firing thru the carb, I adjusted that valve and all was well again, but it was an L block not a J block, but I would still check the valve adjustment, as it sounds like you have done the tune-up without positive results.

Also sometimes you can pull the spark plug wires off one at a time while it is running and see if it changes the idle speed, if it doesn't change the idle you know which cylinder is the problem.

 

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4 minutes ago, wayno said:

Have you checked the valve adjustment yet?

I had a valve get too tight on my L block and the engine started missing, I think it was an exhaust valve as it wasn't back firing thru the carb, I adjusted that valve and all was well again, but it was an L block not a J block, but I would still check the valve adjustment, as it sounds like you have done the tune-up without positive results.

Also sometimes you can pull the spark plug wires off one at a time while it is running and see if it changes the idle speed, if it doesn't change the idle you know which cylinder is the problem.

 

 

No valve adjustments yet, but you've got a good theory. I want to locate the valve cover gasket first. The garage is still a nightmare after the move a few weeks ago and I have a couple dozen identical bins of spares to dig through... and they are all stacked on top of one another. I feel like my one-wire-at-a-time swap may have served the same test as pulling wires while running, but that's easy enough to try as well. However (and this is why I like your flaky valve theory), the truck seems fine at speed. I realize at higher RPM the miss can get covered up somewhat because of the shorter time slice between sparks but 3/4 of 67 horsepower would have a hard time pulling me down the highway at speed... I think.  That's what is leading me away from coil or anything carb-related... it seems like a niss would be isolated to a single cylinder... so, plug, wire, problem post on cap, or... valve.

 

More info when I get some energy to do some work on it.

 

 

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When that valve got tight on me I could hear it more than I could feel it as I still had the power to go down the freeway(LZ23), this happened on my 521 work truck, I also was dragging a trailer, so my foot was in the pedal pretty deep and that just made it louder, it's been so long ago, as I recall it kinda sounded like an exhaust leak which when you think about it it is an exhaust leak.

I also cracked an intake valve once and you know when that happens as it starts back firing out the carb/intake, I was 300 miles from home so I pulled that spark plug wire and drove it home on 3 cylinders, most people would have called a tow truck but I have this talent for getting my vehicles home to fix them under there own power, a few times that has cost me more than if I had called a tow truck because I destroyed whatever was broke getting it home, then I had to replace what was broke rather than rebuild it.

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  • 6 months later...
On 12/8/2019 at 6:42 PM, XXL said:

 

No valve adjustments yet, but you've got a good theory. 

 

On 12/8/2019 at 6:42 PM, XXL said:

More info when I get some energy to do some work on it.

 

 

 

Finally got this resolved, and now I have my missing 17 horsepower back for the neighborhood hills. Cyls 1, 3, and 4 had ~140#. Cyl 2 wavered around 50-60 because exhaust valve adjustment had tightened way up. Adjusted them all, and now getting 140# in all 4 holes. Yay.

 

@wayno called it right. 

 

 

 

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  • 9 months later...

Going to be offering up my 520 for sale. Another project has come my way and I don't have enough room for both (so says my wife). 

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