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My 1971 521


d.p

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This is why I like Datsuns, except for the last couple years(81/82) they are ECU free and because of that they can be diagnosed on the side of the road and more than likely can be fixed good enough to get you home, it's almost always a loose wire as if it is not a loose wire then it was talking to you before it broke, 9 times out of 10 times the transmission will start making noise before it fails, 19 times out of 20 times the rearend gears/bearings will make noise before they fail and it will leave oil spots if leaking(talking to you), it will start running hot slowly before it overheats, the mechanical fuel pump will usually give you warning before it completely fails, the engine will cut out intermittently but it comes on fast, but I drove my 521 work truck within 3 miles of my house from 20 miles away just by taking off the valve cover and pumping the fuel pump arm manually every 2 to 4 miles, I figured out later that if I had taken out the spacer on the fuel pump it likely would have made it the whole way home, but I could not get all the way up that last hill with the fuel in the bowls of the SUs.

If I were in the middle of Africa I would want to be in a Datsun truck, if it had a matchbox distributor I would always carry and extra, otherwise I could more than likely fix it with a volt meter and a Dewalt tool bag full of vintage name brand tools like Craftsman.

Edited by wayno
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Datsun... need preventive maintenance but rarely leave you stranded

If you are forced to the side of the road you can usually fix with a piece of fence wire (done this)

If you can't fix it on the side of the road at least you know what's wrong.

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14 hours ago, datzenmike said:

Datsun... need preventive maintenance but rarely leave you stranded

If you are forced to the side of the road you can usually fix with a piece of fence wire (done this)

If you can't fix it on the side of the road at least you know what's wrong.

This should be on a t-shirt.

 

I am growing increasingly frustrated with how complex even the most mundane modern machinery is becoming. My John Deere riding mower has a computer. My little boy's Kawasaki quad doesn't have a kick starter or a pull starter at all. Only electric start, and they are known for eating up starters (not easy to replace either). The ECM in my carbureted Polaris 700 Sportsman just went bad. If it's carbureted, why the f^$&*k does it need an ECM. The most recent peeve is that the new update on my Android phone means that the flip cover I bought for it now activates the screen at all times and kills the battery in hours, unless I remember to leave the cover open.

 

This modern shit owns us, which is why I keep my 2003 Dodge Ram 2500 4x4 diesel. It's the last of the simple era and I could probably fix it with a piece of fence wire found on the side of the road.

 

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2 hours ago, Stoffregen Motorsports said:

This modern shit owns us, which is why I keep my 2003 Dodge Ram 2500 4x4 diesel. It's the last of the simple era and I could probably fix it with a piece of fence wire found on the side of the road.

 

 

Only the diesel though. If you have the gasser, remind me to buy stock in fence wire.

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  • 2 weeks later...

Fuuuuuuuck this truck.

 

Been sitting since I thought I fixed the starting problem.  Went to drive it today and it wouldn't start so I jumped it and it started right away.  Drove a couple miles parked it came out and it started but as soon as I started to back up it died.   Couldnt get it started even with a jump so I got a ride home got my original coil swapped it out and it started right up.  Put the newer coil back on and it started right up, figured it was a loose wire or bad contact.  Drove home let it sit for a couple hours and now it wont turn over.   Replaced the coil again with the original one to no avail.  It just wont turn over.  

 

What the fuck could it be?  

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I texted you a video?  You get it?  I just assume spark because thats what the problem was a week ago when it wouldn't start.  I swapped the plugs for new ones today but the old ones were fouled.  New ones are white/tan rbut only have maybe 3 miles on them. Compression should be good and I can see gas shoot into the carb when I push the throttle linkage.  

 

I put a test light on the ballast resistor and its bright on one side and faint on the other.  Same with the coil... bright on the positive side and very faint on the negative.  Oh and the ballast resistor gets HOT when trying to get it to start. 

 

I don't know what else it could be? 

Edited by d.p
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Yeah, it it's turning over then the starter is working. If not starting than say not starting.

 

Put an old plug in one of the plug leads and lay on a grounded surface and try starting. Got spark?????

 

YES... ignition seems OK

 

NO.... Check for 12 volts on coil positive terminal while the starter is turning the engine. Bad ground connection on distributor. Points not adjusted and are not opening. Points condenser is shorted internally. Coil is bad.

 

Ignition may not be sending the start signal to the coil around the ballast resistor.

Make sure pedestal is tight or make a ground wire for the distributor. All electricity flowing through the ignition MUST ground through the distributor case and mount on the timing cover.

Clean (file) or replace points set to 0.020" to 0.022".

Disconnect the condenser, if it starts, replace later. If condenser is shorted internally, it's the same as the points not opening.

Coil may fail when it gets hot, replace.

 

 

 

 

 

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Yeah not starting it does turn over but never ‘runs.’   Check whether dizzy pedestal is right??  

 

Running pertronix for over a year now with little to no problems.   I checked for spark but didn’t see any from the #1 wire but it was late and I was over it. I could see spark from the coil wire though.  Will check for 12 volts from + side of the coil and check plug wires again tomorrow.

 

Whatever the problem is it doesn’t seem to be coil related because swapping them out would allowed it to start earlier today.  

 

 

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No, make sure it is tight... making good ground contact.

 

Coil may spark ... but it's not all getting to the plugs. Rotor, cap or wires bad? The cap may be 'carbon tracked'. This is where the insulation has failed and the spark has run along the inner or outer surface to ground or another wire. Once it breaks down it's easier to arc next time. You night see a small trace like a spider's web mark. It can be very intermittent. It can also run down the porcelain on the spark plug.... but you replaced them.

 

More than the coil is affected when changed. You are also removing (pulling on) and tightening wire connections and the coil lead to the distributor is moved. Next time you have it idling try moving the wires and see if it quits.

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OK, this is what you need to do, pull the exciter wire off the starter so it doesn't turn over when you turn the key to the start position, then have someone hold the key in the start position and you check to see if you have 12 volts of power to the positive side of the coil, if you don't then either the key assembly is wore out or someone bypassed/removed the 12 volt start wire to clean up the engine bay wiring, I have found that engines that start easy will start even with the bypass wire removed as when you let off the key the engine is still turning over and they start, and this is from the habit of only turning the key to the start position and letting off as it always started that way in the past, but when it starts to get colder outside they don't start as easy and all of a sudden there is an issue.

What I did to get my truck to start before I figured out the issue was to have a wire with 2 alligator clips, one big one for the positive post of the battery and another smaller one for the positive side of the coil, it started every time after that and I didn't need the wire as after it warmed up, I just hit the key and got the engine turning let off and it started.

You need to understand that when the engine is turning over and you do not have power to the coil it will never start, but as the engine turns when you let off the key the coil gets power but the engine is still turning, I used to just keep clicking the starter and letting off and it would eventually start, at least till it got cold outside, then I had to use the bypass jumper wire.

If it starts with the bypass wire every time, just carry one with you at all times, basically your hot wiring it, now if you have a auto anti-theft alarm/system, that could also cause issues.

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I ordered that relay.

 

I put a test light on the + of the coil while my son turns the key and it lights up.  That tells me it has power right?  

Checked for spark from #1 wire using an old spark plug, it sparks but its orange it it seems intermittent.  

 

Put my old coil on a multimeter measuring ohms, touching center and negative terminal it shows 10.04ohms

touching two posts shows 1-.1.1 ohms

 

New coil shows 9.1 ohms to center

post to post shows 1-1.5 ohms

 

Wiring..

Ground wire from dizzy pedestal to body

red wire from dizzy to ballast resistor

Black wire from dizzy to coil -

black/red wire to + coil and splits to ballast resistor

Green/yellow to + coil

 

Which wire is the excitor wire on the starter?  And how do I check for 12 volts to the coil while starting it?

 

Also with no coil in the truck it behaves the same way it does with the coil attached?! 

 

I tried both coils, replaced spark plugs, other set of plug wires, different rotor cap and no change whatsoever.  SO whatever I am doing doesn't seem to change the behavior at all.  The truck acts like its got no coil even with the coil attached.  

 

It seems to me not enough spark to the plugs when trying to start.  When I test #1 it will spark when I first turn the key OR if I just hold the key between  RUN and START it will spark.   Once I hold the key to START it it stops sparking (while engine is turning over) then will let off a little spark when I release key.  What does that point to?  

Edited by d.p
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Turned the key to what? ON or START. In the On position power to the coil passes through a dropping resistor (ballast resistor) and only 6-8? volts goes to the coil. In the START position the ballast is by-passed and the full 12 volts goes to the coil. A big difference. Both positions will light a lamp but only START has the full 12 volts.

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Ok? But how do I test for the full 12 volts at START?  LIke I said when the key is at START I get no spark from the #1 plug.  If the key is in between ON and START (me just holding it in a position that the engine isn't turning over yet) I get spark.  Shouldn't I get spark from the #1 plug when the key is in the START position and the engine is turning over trying to start?  

 

It seems to me I am getting wildly inconsistent spark so what would cause that? And no enough to start this mfer. 

 

 

Edited by d.p
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