Dieing in traffic ....my 521 saga

[jrock4224]

So been driving the snot out the 521 since the alt swap but had abn issue yesterdcay and need a little brainstorming from my ratsun peeps....so i was balling down the highway at 70 and all of the sudden i lost power ... i clutched it and it started back up and continued on way...did it one more time on the off ramp.....ok wierd little low on gas but 1/8 tank no biggie usually...so i drove her hoem and it was fine after making a few arrons on the way home ...no issues....got home went to leave and it was hard to start ...real hard, not just flooded hard like it has been a few times...but dont wanna start hard...side note while i am cranking and its not catching the ignition light starts on then goes off then will come back on if i stop and restart... got here running she was all loaded up from my pedal jockeying but she ran fine...headed across town and out of the blue it stops running through town at 35 i couldnt get it to refire but once and as soon as i attempted to go it stopped again....never got it to refire.....I am thinking coil or dist....but when i got it hime last night just rolled her in the drive way nd went to bed.....gonna start with check for spark .... anyone had a issue similar to mine that may have some insight....It's wierd that it's sporadic and not just dead....makes me think loose connections but i went over all ten wires three times while waiting for a ride....everthing was good....just acts like its electrical the way it just dies ....outta nowhere...

 

You know i am a true ratsuner....I break down, left stranded...get a ride where i am goin, still party it up and go back later and tow strap my ratty home and go to bed....gotta love the ocasional stranding....

 

any help or advice where to start appreciated....J

[DanielC]

Lets start with the thing you do not need to worry about. The IGN light is really a light that shows your alternator is putting out some juice. Not really charging, but putting out something. Sometimes a Datsun cranks fast enough to make the alternator start to make a charge.

 

If you have a points distributer, do a tune up. Gap the points, set timing, adjust valves, readjust carb. Adjust your brakes while you are at it. Lube the grease fittings too. I know a lot of this is unrelated to the engine dying, but it needs to be done.

 

Auto zone sells a spark tester, for about 5 dollars. It has a ground clamp on it, and a terminal that the coil or plug wires will plug into.

Here is a picture of the spark tester on my boat:

 

Now, for the dying. When was the last time you replaced the fuel filter? It is probably due. It is common on a truck this old to have some crap in the gas tank, and the crap finds its way to the fuel pickup inside the tank. You can blow backwards from the fuel filter to the tank, and dislodge the fuel tank crap some times, but it is still in there, and it will plug the fuel pickup again, later. The real cure is to drop the gas tank, and rinse the tank out.

[jrock4224]

this is all new stuff ...new points new alt. new fuel filter, its got maybe 1k miles on it....and it dies like its electrical ... just boom no studdering no leaning out just flat out loses spark it feels like...thinking its one of threethings the coil the dizzy or that stupid resistor before the coil.....i am going to go through it with a most ofthe things you covered.......just figured someone migh have runinto this after there alt swap project....so far it will start randomly....i will explain somehting... when it does stall out its not gradual its like a switch just boom and it dies...ususally filter or fuel issue will cough and sputter right before it dies this just acts like i shut the key off or pulled the coil wire while running....

[DanielC]

Go and get the Spark Tester, and throw it in your glovebox. When the truck dies, you can then put it on, and find out if it is an ignition related problem.

You might also want to check the fuses, and fuse box, also. After 40 years, they can sometimes cause random electric problems.

 

Compression, Ignition, Fuel. Given these three things, in the proper amount at the right time, your engine will run. Millions of engines prove that every day.

[jrock4224]

alright so that reminds me antoher thing that coinceided with this phenom....so the other day on my way to work i noticed my brake lights weren't iluminating... parking ok, jjust no brake lights... so i checked the fuse it and it was gone...missing...ok wierd I know for a fact i had brake lights before....go home and figure out putting a fuse in it turns the bl on constant.. ok switch is bad....no it turns out the lock nut backed off and the rod had unthreaded till it was no longer tripping the switch...ok adjusted it back and its fine now....but i didn't pull the fuse for the lights and i had one casue before the mal adjusted pedal they worked , meaning there must of been a fuse in it...Ihave no idea how i came up missing....anyway so the crux of this is .... i stole the fuse the day before out of the radio , cig lighter position since i dont have a radio or a cig lighter use.... everything ran fine but now this.... I am gonna test spark tonight when i get home and a few other connections that i thought of today at work....while i am getting that tester i am gonna pick up all new fuses for the box ...that way i am sure its not them cause they are the ones from 197 whatever....maybe i am thinking when i was prying out the other fuse maybe i f ed up the ones next to it.....

[datzenmike]

Or you could just carry an old plug for a tester. Very ratsun.

 

 

I agree that if the fuel should stop it, would stutter however briefly. If it shuts off like turning the key off it may be almost that. Lets assume it isn't fuel and it is electrical.

 

 

All the following must work to provide spark at the coil. Just one thing not working properly will shut the motor off:

 

There must be a solid and secure electrical path from the battery to the ignition switch.

The ignition switch must connect power to the coil and not be intermittent, loose, worn or make bad contact inside.

There are two paths to the coil on a points dizzy. One is when the key is in the START position and sends 12 volts directly to the coil + terminal. The other is in the RUN position and sends 12 volts to the ballast resistor to drop it to about 8 volts and then on to the coil. Both these are selected by the ignition switch.

The ballast resistor gets HOT and may break it's connection, then cool down and begin working again.

The coil gets HOT and may stop working until it cools down.

There must be a solid and secure connection between the coil - and the distributor points. A loose wire could cause an intermittent on or off.

Badly adjusted or worn points could also interrupt flow.

The distributor must be securely grounded to complete the electrical circuit.

 

 

Some of these things can be checked others can only be truly tested once its tops working.

 

Suggestions:

 

When it is running: (not driving)

Wiggle the ignition key around in the lock. Reach under and move the wires that plug into it. Can you get the motor to stall or run erratic? If so there may be a loose connection on or in the ignition switch.

 

Gently move the wires going to and from the ballast resistor and coil. Don't go near the high voltage coil wire.

 

Ground the dizzy, tighten mounting bolts.

 

 

When it quits and won't start:

 

Place an old plug in one of the plug wires and lay on a grounded surface and crank... you should see spark. If no spark:

 

Carry a $5 test lamp and look for power on the + coil terminal when cranking in the RUN position. If no voltage suspect the ignition switch. If there is voltage check the - side of the coil. If nothing the coil may be bad. If there is power on the - side suspect the dizzy points or ground.

[Sudo]

Or you could just carry an old plug for a tester. Very ratsun.

 

 

I agree that if the fuel should stop it, would stutter however briefly. If it shuts off like turning the key off it may be almost that. Lets assume it isn't fuel and it is electrical.

 

 

All the following must work to provide spark at the coil. Just one thing not working properly will shut the motor off:

 

There must be a solid and secure electrical path from the battery to the ignition switch.

The ignition switch must connect power to the coil and not be intermittent, loose, worn or make bad contact inside.

There are two paths to the coil on a points dizzy. One is when the key is in the START position and sends 12 volts directly to the coil + terminal. The other is in the RUN position and sends 12 volts to the ballast resistor to drop it to about 8 volts and then on to the coil. Both these are selected by the ignition switch.

The ballast resistor gets HOT and may break it's connection, then cool down and begin working again.

The coil gets HOT and may stop working until it cools down.

There must be a solid and secure connection between the coil - and the distributor points. A loose wire could cause an intermittent on or off.

Badly adjusted or worn points could also interrupt flow.

The distributor must be securely grounded to complete the electrical circuit.

 

 

Some of these things can be checked others can only be truly tested once its tops working.

 

Suggestions:

 

When it is running: (not driving)

Wiggle the ignition key around in the lock. Reach under and move the wires that plug into it. Can you get the motor to stall or run erratic? If so there may be a loose connection on or in the ignition switch.

 

Gently move the wires going to and from the ballast resistor and coil. Don't go near the high voltage coil wire.

 

Ground the dizzy, tighten mounting bolts.

 

 

When it quits and won't start:

 

Place an old plug in one of the plug wires and lay on a grounded surface and crank... you should see spark. If no spark:

 

Carry a $5 test lamp and look for power on the + coil terminal when cranking in the RUN position. If no voltage suspect the ignition switch. If there is voltage check the - side of the coil. If nothing the coil may be bad. If there is power on the - side suspect the dizzy points or ground.

 

I have to say: "good post". 

 

 

I'm thinking of printing it off and posting on my garage wall. If I would have a dad around I can only imagine (hope) he would have said something like this. The calming influence of some nuggets like this during a shit-fit freak out session when something electrical is mystifying me would have really furthered my inner greasemonkey development.  

 

 

 

 

good luck jock figuring it out. I don't envy anyone with intermittent electrical gremlins. 

 

 

[jrock4224]

i agree mike thank you thats exactly the kind of info i was hunting for.... cant wait to get home and try these suggestions out...

[ronnny]

I have a 720. But hey. Have you checked the ground from your motor to the battery or body? I have not had the problem on my 84 but on the 81 in ended up being a loose wire somewhere near one of the coils. Something before the two coils got power because they both would drop out spark at once unlike other times when a coil wire came loose and would run like crap on only one coil. Have you took the dist. cap off and checked to see how good it looks in there? Maybe between the center of the button and where it touches the cap is starting to get a bad connection.

[67_1600]

I had a very similar problem with my Roadster not too long ago - it would just completely die at times like it had lost all power. In my case, I tracked it back to one of the wires on the coil being just loose enough that when there was a significant amount of vibration it would lose the connection altogether and the engine would die just as if you had shut off the key.

[mklotz70]

Along with the wiggling Mike said to do....I'd do the same thing around the fuse box. That type of holder/fuse combo is prone to getting loose and having poor contact. I'd remove it and glass bead it, but most guys won't be able to. You can use a fine wire wheel on a dremel to clean up the contacts. An emery board will work too. Keep a 3' jumper wire with you....if it dies again...jumper straight from the batter to the + on the coil and see if it starts back up. If it does, you have bad contacts in the ign circuit......if it doesn't, you may have a bad coil. I'd also carry a cheap test light....you can check for pulsing light on the neg coil term while cranking if it doesn't fire up with the jumper. If no pulsing, the points/condensor are bad. If EI, you probably lost ground to the matchbox....hook the jumper wire from the neg batt term to the body of the dizzy and try starting.

[Roadracer Al]

I'd also suggest taking out all the fuses and using some scotchbrite to clean the little clamps that hold the fuses. My '73 620 was so corroded that the headlights were dim, and the wipers didn't work at all. 10 minutes cleaning the fuse box fixed that pretty well.

 

As an aside, the corroded connectors will heat up enough to melt the plastic in the fuse box, making it even more likely to not connect. Mine needs replacement, and I already have a small marine-grade fuse panel for the job. Just gotta break out the soldering iron...

[ariascarlos1990]

I say check your fuel filter again. This happened to me the other day. When the tank got low on gas it instantly clogged my filter there may me some gunk in the tank. It would start for a second then bog down and die. replaced the filter and BROOM! runs perfect to this day.

[datzenmike]

I'm using his statement:

 

this is all new stuff ...new points new alt. new fuel filter, its got maybe 1k miles on it....and it dies like its electrical ... just boom no studdering no leaning out just flat out loses spark it feels like...when it does stall out its not gradual its like a switch just boom and it dies...ususally filter or fuel issue will cough and sputter right before it dies this just acts like i shut the key off or pulled the coil wire while running....

 

... on the face of it, sounds electrical.

[banzai510(hainz)]

since you say your running points. Ck the coil if HOT and ballast and ck points if pitted.Soon as this happens.

ponts you want high resistance in circut.

 

make sure your alt isnt overvolting.

[jrock4224]

so i got spark or at least intermintently...everytime it dies i pull plug and check spark.....it has spark.. and good spark....the wierd thing is that when i pull the plug to check spark the f ing thing starts up with out the plug in the hole...and runs on three cyalinders....never had that happen before....so at the coil on the positive side i am reading 10-11 v...on the ceramic resistor i read like 6.5 to 7 volts on one side and some ridiculously low number on the other side....starts up rpetty regualarly...I saw the fuel filter was empty but onece i cranked it over it filled up and has been since...i dunno havent road tested it but one time it died like described in the driveway....dont really wanna leave the house and have to get tow strapped again...gonna fill with fule today and make sure im not having a delivery problem and maybe a short round the block road test....all of those readings were with the key in the run position with out the truck running....

[banzai510(hainz)]

thats about correct with voltage readings..

yes it will run on three cylinders.

Most time I ck for spark on the center coil wire. I usually dont ck out to the plugs unless I think or feel I have lost a cylinder.

 

ck the hot is hot while its running. If Ok I will assume its good.

 

 

remember 521 the fuel tanks and filler hose is in the wheels well and can get dirt in the tank. which might clog the idle jet or even a main jet in the bowl. I run now 2 filters on my 521. the stock type and then a inline one to the carb.

[jrock4224]

all right so i did all and the voltages seemed to be okay one side of the resistor hasu nore more than .1 volts coming out of it...any way so i went through the fuse box and i went through all the connections and cleaned thenm up and recrimped ends to grab spades better and it seems o run... it ran for 15 minutes in the driveway and starts back up everytime.....i wont really know till the beast hits the road... which end of resistor is the positive end and what should the voltage be... on the coil its 12v in on positive and 6 v on the negative side....the resistor was hard to get a readin but in the nines on the side that hooked to the positive on the coil and the .1 on the side that went off into the harness......might try and drive it today if i can plan for a tow strappping if needed.....

[jrock4224]

so i drove it and seems to be no ill affect ... it must been the old loose wire i hope... anyway replaceing the fuel filter while i am at it too, and cleaned up the fuse block and contacts... seems to stay running even under a load.....anyway thanks to all for the help diagnosing my issue... i will fire this thread up again if it resurfaces.....Im glad cause i just raised the money to take that dfv off and get the right carb from racetep.... :cool: