Help diagnose

[SulphurDave]

I just picked up this '72 521 yesterday in a rush before others bought it (off Craigslist) with high hopes I could get this thing to be a daily driver with minimal work and little cash. Today it's looking like this will be a bigger project than I thought. I'll post pictures after I clean it up it's been sitting in the woods not running for years. I wanted to post this video of it running, barely, since that's the biggest issue first. The choke cable is broke or stuck not even sure the choke is doing anything. After a very clickity clickity starter it'll finally grab the flywheel and turn the motor over and of course it won't idle I have to step on the gas pedal and pump it to the floor to maintain anything. It struggles a lot to rev, hold a rev, idle and eventually dies out. Like I said I'm only 2 hours into this truck today so I'm starting with this first. It needs a lot of work. I'll get to all that later.

 

[datzenmike]

Getting too much air not enough gas... primary jet partially blocked with old dried up gas.

 

Engine off, look down the carb and pump throttle. You should see a strong squirt of fuel shoot out into primary barrel from the accelerator pump. Look in glass on front of carb, is fuel up to the mark?

[SulphurDave]

I don't see a squirt of fuel at all when I pump it

[wayno]

Welcome to Ratsun B)

I have not a clue about downdraft carbs, but your in the right place.

[datzenmike]

I don't see a squirt of fuel at all when I pump it

 

Well I would rebuild the carb. Get a good kit and some carb dunk, lots of newspaper, and a clean kitchen table. Allow several hours.

[SulphurDave]

I know it would it be better to throw a Weber 32/36 on it and change to electronic ignition but is it worth it per dollar invested versus rebuilding stock carb and then waiting for the next problem?

[banzai510(hainz)]

Sulphur, La????????? Buy a boat

 

To me a new carb or a weber is a given along with a electronic ignition.

 

Right off the bat I would pull the fuel line on the output side of the carb. point in a safe direction and see if gas shoot out. Should be a good amount. If yes then hook back up to the carb.

 

If you got a stock carb there is a glass in front and ck the float level. If good then pump/cycle the gas and you should see gas squirt in the main barrel. If NOT then the accel pump part of the carb might be bad.

 

Last time I seen this on a neiboors he didnt have gas squirting in the main barrel of carb but it was a emplty fuel bowl as I trouble shoot backwards to the fuel pump.

 

since you got a 72 you have a electric choke also

 

go to oldddatsun.com the tech section and read everything!!!!!!!!!!!!!

 

 

also do not swap ignition coils or anything. Unless its made esp for that year and model.

 

Most often its just points bad or out of gap spec or condensor bad.So ck the point gap and timming.

Water under distributor also?

 

ck make sure the intake bolts are tight(remeber these are aluminum so its not that much)

carb bolts tight.

 

This is a cool truck(same color as mine) this is a EZ fix!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

[Rays74]

Defo sounds like it's lean, Dave........ check your fuel delivery like Hainz mentioned then if all's good, get with that carb (OR throw money at the prob and pay the Weber man.......me, I'd rebuild the orig ) and while doing that go ahead and do a full tune up...... including first checking your compression #'s then moving to valve gapping/check and igintion work.

Crossing my fingers you have a decent base to work with :)

 

Welcome and congrats on the 521 :)

[banzai510(hainz)]

I would do a valve lash ck also

[SulphurDave]

Yea I pulled the fuel line off the carb, pulled the coil plug on the dist. cap, spun it over and gas shot out pretty hard so it's getting fuel to the bowl and the fuel is at the float line.

 

Check out my new post with pictures...

 

http://community.ratsun.net/topic/47011-i-saved-this-jewel-from-a-certain-death-in-the-woods/

[datzenmike]

...Look in glass on front of carb, is fuel up to the mark?

[SulphurDave]

.

 

since you got a 72 you have a electric choke also

 

 

I have the choke knob on the dash... I'm pretty sure. That's an electric choke? Or maybe I'm confused.

[datzenmike]

It may have an older carb and be fitted with a manual choke cable and knob. An electric choke is fully automatic and no knob needed.

[SulphurDave]

Yea the gas is at the fuel line mark. Carb probably needs a kit and a good cleaning.

[banzai510(hainz)]

OK I forgot to mention

 

I worked on a 521 that would almost have this same proplem.

 

I had to have the trottle open alot to keep it running.

 

it was a combination of things.

Carb was loose and the mixture was out of adjustment.

 

521s have sediment issues cause the fuel line is in the wheel whell.Water can work down the fuel fuiller tube and rust out and dirt can also work down

I would replace the filter, Fram make sa common filter. Take the old one and open it up and see what the condition is.

This could plug a idle jet or maybe even a main jet. Youll be able to tell if the filter is bad . If good then assume the carb is mostly clean.

 

Now the 521 I was working on what i did is get the motor running like you did but block the main barrel with your hand and stick a screw driver or what ever to open the 2nd barrel up a little/alot and the motor should stay running once you get the rpms up and theres a vaccume to suck the gas. Now if it runs OK(assume then ignition is good) like this then you know its a carb issue on the main barrel side. Like accell pump, ,mixture setting at idle. or a main barrel .

 

 

I would ck the coil to make sure the ballast resisitor is there and feel if its HOT ,just in case soembody put a later model coil in there and its drawing to much current cooking up the points. But it doesnt have that poping sound which is a good indication of that.

 

as for the lights and stuff. ck the fuse box. and soemtimes reseating the plug in back of the instrument panel will clean the contacks and make things work.

 

Thats a nice truck.

 

 

take motor photos of the areas and we will guide you thru it.

 

This is a EZ fix on most of this stuff.

 

side marker lights usually rot out from the iside or broken bulb that is now rusted stuck in there.

TR3 cleeaner polish will make that truck have that nice wet look.

 

OK I see you started another thread. Lets keep it to one. otherwise you/we wount be able to keep up.

 

on the turn signal swap the blinker cans under neath. there will be 2 of them see if the proplem moves.

soemtimes a bad bulb will make the whole sytem look bad or act funny.

 

if the wiring is not hacked its always a corrorssion issue. clean contacks

 

the trans shifeter being sloppy is common on those trans. Pull the cover off inside the cab and put it in gear and youll be able to see how the fork attaches to the rod with a pin. Over time it opens up. I pull the pin with the C or a E clip(do over a drive way so you can find when you drop this.) You can try to sqeeze this together or get a bolt with a good not and squezze it. and will be be a litlle tighter but it will get loose again.

[SulphurDave]

I would ck the coil to make sure the ballast resisitor is there and feel if its HOT ,just in case soembody put a later model coil in there and its drawing to much current cooking up the points. But it doesnt have that poping sound which is a good indication of that

 

That's funny because I burned the hell out of my arm twice on the coil when I was running it and puzzled me why it got so hot like that. I mean it's HOT. Why is this?

[banzai510(hainz)]

The ballast resisitor cut the current in half.

Points do not want alot of current. It will arch out the points(burn them up)So they come with a Point type coil. They designed to run on 6 volts.

 

Only on START they get 12volts. They will be 2 wires going to the +side coil. One of these will be the HOT START wire(12volts during START( then when key goes to ON. the blk WHT wire feeds the ballast resisitor then comes out and goes to the Plus side coil.

 

Thats why I said take a photo of the engoine and coil area and mayeb soem thing is missin or a wrong part installed.

Theres a habit of people buying big go faster looking Bling Coils and thiking its going to be better and they only make it worse.What proplem they had then truck is on the side of the road or in the woods as your case when you bought it.

 

One way to ck this also is ck out the points.See if burnt. Then put a new set in and run it. They usually burn up pretty fast.

 

You still might have a carb issue but read carefuully what I did on the carb and try it out.

 

take photos!!!!!!!!!

[SulphurDave]

Ok thanks bro!

 

Pictures of the build process are here ---> http://community.ratsun.net/topic/47011-i-saved-this-jewel-from-a-certain-death-in-the-woods/