521 coma

[Beginer]

So my truck died one day like I had stalled it and then wouldn't start back up.

 

Before it did that it was having problems maintaining speed on the freeway, would start to cut out then go to idle. So i figured just needed a tune up so I ordered my parts but had the wires first so i replaced them and drove home and she died just before i parked.

 

The few things I'm certain work are the fuel pump, coil(new), carburetor(just rebuilt), spark plug wires, cap, rotor, points.

 

Everyone in my house seems to think its my timing chain, but i don't see how that could be.

 

Please help anyone that has any input, thanks

 

 

Forgot to mention i guess it has a L16 engine in it, and haven't been able to start it again since it died

[808DA6]

Check your fuel filter lately? I ran double filters on my 521. Lots of rust over the years.

 

-B

[exit64]

Turn it over with the dizzy cap off. If the pointer is going around, it isn't your timing chain. Did you check for spark? You might have a bad coil, even if it is new. If it runs OK cold and then starts to miss as it runs for a bit, that is one of the symptoms of a coil going bad. Also, dump a little bit of gas straight down the carb and see if it fires then. If so, you have a fuel delivery problem. Don't guess at the problem, diagnose it. Engines only need 3 things to run and if you are missing any of them, no go. Have fun.

exit64

[banzai510(hainz)]

was the coil a dircet replacement coil????? It should be otherwise a wrong resisitance coil will fry the points.

 

ck for spark

I would adjust the valve lash also just to be sure its good.

 

 

this is a simple fix.

 

ajust or ck the point gap if still running points.

 

 

521s have a proplem of gas getting alot of dirt in there but if it idles OK then you know the idle jet is not plugged.

 

make sure your wires are hooked up on the ballast resisitor and coil. You put the + to coil right and not swapped them around?

 

its not your timming chain. Could be timming distributor related or carb.

 

Pull center wire off the distributor cap. take that wire and place near ground/metal. start the truck and see if it sparks. if sparks I say its good. If not spark ck point gap.

 

Ck points if has a bad pit in it. If they are fryed really bad and they were NEW when You installed itthen you have a low resistsance coil

[nukeday]

Um, what year 521? L series or J series engine?

 

My thread is looooong, but there is quite a bit of good troubleshooting in there from several guru's here on the site. Instead of reading the entire thing, start here and see what you find.

 

If you've got an hour, the whole mess is here.

 

Good luck. I owned a blue '72 521 when I lived in Sunnyvale. I'll try to find a pic of it, last time I saw it, it was parked at the Brass Rail...

[hang_510]

X2 on the dual fuel filters!

...and that new doesnt mean its good.

 

 

If the pointer is going around, it isn't your timing chain.

unless it managed to jump a tooth ... :mellow: (not likely either)

[Suspect]

I've run into alot of things with my 77 Datsun, one that stumped me the most was the simplest fix. My truck was running fine then all of a sudden it run horrible and I barely made it back to the house. After I got there it wouldn't start. I swapped everthing I could think of and still nothing helped. This occasion it was the wire that powered the points that goes threw the distributer casing to the point. It had curoded so it would get spark but not right. I would check there if nothing els helps.

[MikeRL411]

If you are running points, check the capacitor. If its shorted you will weld. or at least build a big pit/mountain pair that kills the spark since the points cannot interupt the current flow. No break, no spark. Far out alternate error, but I experienced it, the ground return wire [the one that goes through the housing, its not a voltage wire] to the point set is "extra flex" fine diameter braided wire. It can break with age and then no ground. Pull the wire from the housing feed through to the screw on the points and feel for a discontinuity. I replaced mine with the wire from an old capacitor set. A bit stiff, but by folding it into an "S" shape it has enough travel. If you have a parts store nearby, look at the Volkswagon water cooled engine point sets. They use the same type of extra flex wire and are smart enough to provide a new wire with each new point set.

[nukeday]

If you are running points, check the capacitor.

This is also commonly called the 'condenser'.

[Jersey]

I've run into alot of things with my 77 Datsun, one that stumped me the most was the simplest fix. My truck was running fine then all of a sudden it run horrible and I barely made it back to the house. After I got there it wouldn't start. I swapped everthing I could think of and still nothing helped. This occasion it was the wire that powered the points that goes threw the distributer casing to the point. It had curoded so it would get spark but not right. I would check there if nothing els helps.

The same thing happened to me on my '72.5 620, I drove it to the dump and came home and it wouldn't start...for 3 days I was perplexed, and then I saw the wire and replaced it and it fired right up.

[Beginer]

I got it fixed, I think it was the points. But then my fuel pump decided to die on me, I should have her road worthy again by tommorow, planning on taking her on a trip back up to Oregon. Thanks for your guys help