521 advice

[kcmwalker]

Hello everyone,

 

I have a '71 521 that I've been working on for a couple months now. It's been well used, but there is no significant rust anywhere. Amazing for a truck that's been in South Carolina for more than 50 years. When I got it, it was stuck in reverse, a little smokey, and was having fuel delivery issues. Since then, I've gotten the transmission sorted and replaced the battery. The battery is getting juice from the alternator, but the starter only clicks when I turn the key. It will start on a jump. I'm thinking the hot start mod is the solution here and I've got relays on the way so I can do the work later this week. I am more perplexed over the issues with the fuel system. After getting it running, the truck died while driving. I replaced the fuel pump and that fixed it, but then I drove to the gas station to fill up the tank. As I was pumping gas into the tank I hear a splash and look down and I've got fuel all over the ground. The rubber line from the gas tank out feed slipped off of the breather tube and emptied everything in the line onto the ground. I put the hose back on and have checked for kinks, but I'm still not seeing any fuel at the carburetor. My best guess is that I've got a blockage and I should probably clean out the gas tank and replace some of the lines. Anyone else have any thoughts about this or any other advice going forward. Thanks!

[datzenmike]

How did you jumper the truck to get started??? If just cables to the battery clamps gets it to work then not needing a hot start relay. If jumping 12v from the starter to the solenoid makes it work than yes the start signal is weak. You can confirm by testing the voltage in the wire to the solenoid in the start position on the key.

 

Take the fuel line off the carburetor and direct into a suitable container. Take the wire off the coil so the engine won't start. Crank the engine over with the starter What you should see are strong gushes of fuel from the pump.

 

If it does.... then something wrong with the carburetor. Possibly screen at inlet is plugged. Possibly the float is stuck or inlet needle valve stuck. Tap inlet with wooden hammer handle to loosen.

If it doesn't supply fuel..... then take the inlet to the pump off and  put into a container of fuel. Repeat the above test. Got fuel???

 

No... the pump is bad. Arm fell off... replacement parts are crap these days.

Yes.. fuel line is possibly clogged. The hose at the tank or at either side of the fuel filter may have a loose clamp and sucking in air rather that drawing fuel. A hose may be kinked. Check and tighten all clamps

 

If still nothing, take gas cap off and blow compressed air back through the lines to the tank.

[kcmwalker]

Hey, thanks for the advice! I've tested my voltages and I think one of the cells in the "new" battery (which was used and basically free) must have gone bad since I put it in because I'm reading anywhere between 10v and 10.5v when the truck is off. With the truck running I'm getting 14.3 so I think the alternator is alright and it's just the battery that's failing to supply the voltage to activate the starter. I'll drop a brand new one in after I get the fuel system in order. In that regard, the fuel pump is still good, it's pumping gas and the truck will run off an external can. I replaced the strainer just because I had one and blew out the lines and now it'll run off the gas tank as well. I guess I'll be pulling the tank and cleaning it out this weekend.

 

I've noticed a couple minor things I'm curious about. First, the radiator overflow hose seems to direct any overflow straight onto the ground. Is that right? If not, where should it go? And my gas cap, while seeming very original, doesn't seem to fully stopper the fuel pipe. It's only gripping one side of the mouth it fits in leaving a small gap open one one side. Just wondering if anyone else has ever had an issue like that.

[banzai510(hainz)]

1 hour ago, kcmwalker said:

And my gas cap, while seeming very original, doesn't seem to fully stopper the fuel pipe. It's only gripping one side of the mouth it fits in leaving a small gap open one one side. Just wondering if anyone else has ever had an issue like that.

the lip is not cathcing. maybe need a new cap

 

1 hour ago, kcmwalker said:

the radiator overflow hose seems to direct any overflow straight onto the ground.

I have a plastic Bottle with cap on there and route the hose to it  size the hose hole(drill).  I usde a flip cap with the red level so it pops if really hot. the standard non lever csap uses a catch bottle But I never use one on a 52 ir ever seen one if there was one.

 

 

yes 10.5 volt on Battery is not good esp when you drive it and still have 10.5.

Just make sure the battery isnt draining by chance.

[datzenmike]

3 hours ago, kcmwalker said:

 

 

I've noticed a couple minor things I'm curious about. First, the radiator overflow hose seems to direct any overflow straight onto the ground. Is that right? If not, where should it go? 

 

The 521 radiator overflow does dump onto the ground.

 

Some time in the '80 a coolant recovery bottle was added. You need the special rad cap for this to work but any bottle or container will work. The overflow hose has to go to the bottom of the bottle and be submerged in coolant. When coolant is expelled on a hot day after shut down the half full recovery bottle saves it. When  the radiator cools down a suction siphons the coolant back into the rad filling it. 

 

I used to top up every week and water just dilutes the antifreeze over time. I put a coolant recovery cap on the rad and now I only add at most a 1/2 cup a year.

[gene knight]

On 3/30/2022 at 4:32 PM, datzenmike said:

 

The 521 radiator overflow does dump onto the ground.

 

Some time in the '80 a coolant recovery bottle was added. You need the special rad cap for this to work but any bottle or container will work. The overflow hose has to go to the bottom of the bottle and be submerged in coolant. When coolant is expelled on a hot day after shut down the half full recovery bottle saves it. When  the radiator cools down a suction siphons the coolant back into the rad filling it. 

 

I used to top up every week and water just dilutes the antifreeze over time. I put a coolant recovery cap on the rad and now I only add at most a 1/2 cup a year.

620's use a overflow container

[datzenmike]

Corrected. '78 and up had coolant recovery systems.

[kcmwalker]

Thanks again everyone,

 

I've cleaned out the tank (it was definitely the source of my fuel delivery issues) and now that it's back in the truck with a new battery, it is running, but not quite ready to drive. Sometimes when it's cold it'll just die when you accelerate. My driveway has a decent grade upward to the street and it'll stall out and die trying to climb it after its been sitting overnight. When it's like this it idles low and rough and dies, but if I rev it a bit to warm it up, it'll run ok once I can get the choke pulled out without it dying. I've noticed it helps if I put it in reverse; when I shift back to neutral it idles much better (after its run a bit first).  When I drive it, it smokes a little when accelerating. The smoke looks sort of blue and hazy and the truck smells smoky after driving it around.

 

I haven't done an oil change since acquiring the truck so that's the next thing I'll be doing along with new plugs. Wondering what else I can do to get things running more smoothly?

[banzai510(hainz)]

is this a stock carb?

I run 2 fuels filters, the stock one then one in line. this keeps the dirt out of the idle jet .

 

as for going up hill part it could be the needle valve on the carb having dirt go thru it before you cleaned the tank. or float needs adjustment.

 

carb is tight. Choke works good?

 

I do a mexican tune up sometimes I run a lot of carb cleaner threw it while running then rev it up and put a rag over the carb so it suck the dirt thru the jets. or sucks the dirt out from the rag and plugs it up again

 

plugs unless real bad wont change anything. I have seen them fix bad running motor. usually the electrode is smashed or gone. otherwise they still work.

 

mosture under the dist cap can give symtoms like this soemtimes.

[datzenmike]

Try adjusting the fast idle cam to rev it up more when the choke is on. This will speed your warm up and give you more power when cold.

 

 

Find this little linkage and put a little bend in it to shorten it slightly. This will pull the fast idle cam up into position sooner.

[banzai510(hainz)]

MIke 521s had a fast idle cam? 

[datzenmike]

Can't say for sure. Has to be some form of fast idle when choke is on. Or engine just soaks in gas and quits. Maybe choke pull just pulls the throttle open?

 

I had a '71. Melted the throttle cable from battery falling over. Pedal was frozen at idle. Pulled choke on and set on fast idle drove home 15 miles of fast idle and 3rd gear. # AM... cop even stopped me and shook his head.

[mainer311]

521’s had a secondary linkage on the Hitachi that would crack the butterfly open if the choke was pulled far enough out.

[datzenmike]

That would explain it. This was almost 50 years ago, I knew less than nothing. Now I know that there is even more I don't know.

[kcmwalker]

Hey everyone,

 

Just want to thank you all again for your help and patience. I've been following your various recommendations and the truck is running great now. It's not smoking anymore, but sometimes the idle is still too low when it's cold. The more I'm driving it the less I'm having any issues. I still haven't adjusted any of the idle linkage, but I'll keep it in mind if my idle problems worsen or come back. It is the original hitachi carb btw.

 

My gas cap still isn't engaging properly and I can see the rubber o ring that seals the mouth is worn out. I'm inclined to replace the rubber - what should I use? Should I just buy a new cap?

 

 

[thisismatt]

McMaster has Viton flat ring seals...might see if they have something of the right size

 

https://www.mcmaster.com/flat-ring-seals/square-profile-chemical-resistant-viton-fluoroelastomer-o-rings/

 

 

 

 

[kcmwalker]

And another question,

 

I've got the original ignition key, but the eye is pretty worn out and I'd hate to loose it. I want to make a couple spares, but I've been all over town and no one can help. I've had several locksmiths send me home with free keys to try, but none of them are correct. I know there are 4 versions of these keys and I've seen lots of charts with various codes to identify them, but none of it has helped me find anything that matches my key online. I'll do my best to explain which one mine is.

 

The truck is a 71 and the key code is 5775. The key is the stop sign version with the groove that gets cut to right. On the back side, the channel is not central, but very near to the right side.

 

If any of you have keys, I'll gladly buy them from you. Otherwise I'm just looking for information to help me find the correct blank.

 

Thanks again!

[thisismatt]

Post pictures of both sides. The pattern is called the keyway. Not sure if that helps with your search...

[MikeRL411]

1 hour ago, kcmwalker said:

And another question,

 

I've got the original ignition key, but the eye is pretty worn out and I'd hate to loose it. I want to make a couple spares, but I've been all over town and no one can help. I've had several locksmiths send me home with free keys to try, but none of them are correct. I know there are 4 versions of these keys and I've seen lots of charts with various codes to identify them, but none of it has helped me find anything that matches my key online. I'll do my best to explain which one mine is.

 

The truck is a 71 and the key code is 5775. The key is the stop sign version with the groove that gets cut to right. On the back side, the channel is not central, but very near to the right side.

 

If any of you have keys, I'll gladly buy them from you. Otherwise I'm just looking for information to help me find the correct blank.

 

Thanks again!

 

The "key code" that you quote is more than Likely the code for the lock and key cut.  The lock smith [or hardware store key cutter] use this info to set up the cutter head.  It has no relation to the key blank.

[thisismatt]

6 minutes ago, MikeRL411 said:

 

The "key code" that you quote is more than Likely the code for the lock and key cut.  The lock smith [or hardware store key cutter] use this info to set up the cutter head.  It has no relation to the key blank.

 

Yes, and it is typically the depth of the notches, corresponding to the number of pins in the lock cylinder. Not sure if that's true for 50 year old Datsuns, but it's true for normal household keys, like Schlage & Quikset keyways

[datzenmike]

I obscured the key code so someone can't cut another key for your truck.

[kcmwalker]

On 4/26/2022 at 11:59 AM, thisismatt said:

Post pictures of both sides.

Here are the pics:

[thisismatt]

I believe it may be a DT3 blank, but I'm not 100% sure as I've run into weird variations as well.

 

This place supposedly has them...they're even nearby in South Carolina 

 

https://keymateinc.com/shop-online/key-blanks/automotive-keys/metal-head/ilco-dt3-key-blank-nissan-detail.html

[thisismatt]

Or DT2... 😅

https://keymateinc.com/shop-online/key-blanks/automotive-keys/metal-head/ilco-dt2-key-blank-nissan-detail.html

[thisismatt]