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All of the sudden she started knocking


pwrcat4000

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Okay I'm still perplexed here I've got the truck to where it will run still have not got the clutch figured out but decided to take it to a transmission shop it's too big of a deal for me to deal with plus its been sitting in my shop for over a month and a half

Anyway, I'm still having trouble with the ignition it will start the truck run the truck but when I turn it off the ignition it does nothin.

Currently this is how it is connected.

There is the swiched wire from the stock harness that used to plug into the resistor, coming to the positive post on the 620 coil

from that same positive post I ran a wire to the distributor contact B.

From the negative coil post there is a wire running to the distributor contact C.

When I turn off the ignition the truck continues to run if I disconnect the factory wire from the positive side of the coil the truck dies.

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Okay I'm still perplexed here I've got the truck to where it will run still have not got the clutch figured out but decided to take it to a transmission shop it's too big of a deal for me to deal with plus its been sitting in my shop for over a month and a half

Anyway, I'm still having trouble with the ignition it will start the truck run the truck but when I turn it off the ignition it does nothin.

Currently this is how it is connected.

There is the swiched wire from the stock harness that used to plug into the resistor, coming to the positive post on the 620 coil

from that same positive post I ran a wire to the distributor contact B.

From the negative coil post there is a wire running to the distributor contact C.

When I turn off the ignition the truck continues to run if I disconnect the factory wire from the positive side of the coil the truck dies.

 

Obviously this is NOT switched and stays on to keep it running when the key is off.

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I used a test light on it. Lights when the key is on it will not light when the key is off however when the truck is running it doesn't seem to matter where the key is, on or off if I disconnect it with the truck running and the key off the truck dies. The test light is off on that lead so it's definitely switched I don't understand it either, that's why I posted

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I have a question, when the key is off and the engine is not running, can you activate the starter with a remote trigger and have the engine start?

If it does start, it's not a clean switched power source.

I would guess that something like a radio or an aftermarket gauge is wired wrong, or the former owner has wired something else wrong, isn't custom wiring awesome.

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The engine and dizzy are out of a 1979 620

Voltage regulator is that on the alternator?

It occurs to me that the alt may be not hooked up right either

since I get the IGN light when the truck is running

but I was tackling one problem at a time so I did not mention it yet.

Maybe they are related.

 

BTW

Currently the truck is in the shop getting the clutch fixed.

I gave up trying to fix it my self and have decided to "throw $$$ at it"

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well info is important.

this is a 521 truck. a 521 still usues a external volt reg as its a older style alternator.

If you installed a newr 79 alternstor the volt reg is inside the alt. now you either have to convert the 521 to use the later 79 alternator.

You can do this by ADDED jumpers where the old volt reg plugged in.

Now i commented on the the volt reg in a earlier post but you didnt mention the 79 L20 and the 79 alt. This would have helped!!!!!!!!!!

 

This will be in the How to section and all over this site if your on here often as this is talekd about all the time.

 

also if you have a electric choke this needs to be disconnected also as you drain the battery

 

 

as for the clutch. a 620 will use a 2245mm pressure plate and youll need the TO bearing and the sleeve for this set up.There could be issie with the slave cylinder also. I using the newer type with a NON adjustable rod but assume you use the T/O fort from the 620 trans. But assume your using the 521 trans with the threaded slave cylinder rod and the Trans Fork with the Hole in it that the 521 uses

 

 

this is all a SIMPLE fix. you need to stay on here and tackle one at a time as we guide you thru this. Not dissapear for a month with another proplem.

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I agree with Hainz however I have had times where life gets in the way of working on my Datsun.  Also there are many people replying to this thread and it can get confusing.  Trying to decipher all the different information can be overwhelming. 

 

powercat4000 Hainz knows his shit.  They call him the "L Motor God" for a reason.

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the trans shop might not know whats wrong either if the parts swap was wrong. You got to mention what cletch and T/O bearing and if sleeve was used.

 

if you got this l20 from a 620 you better have gotton the T/O bearing and sleeve from the donor truck(you said 79 620)

if you just used your 521 stuff this is wrong. As most people just yank the motor and leave the trans and the T/O bearing on the fork

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Banzai510(hainz)

From earlier in this thread.

 

I used this exact Part

http://www.rockauto.com/catalog/moreinfo.php?pk=220404

 

BCA_DNF01576C.jpg

 

I have talked tho the trans guy and explained the differences to him.

I am %80 sure it broke the center out of the clutch when i reinstalled the motor and tightened the bell housing bolts.

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UPDATE: Just talked to the transmission guy the clutch plate was down to the rivets, center was intact.

I am going to bring him the original throw out Bering and collar from the 620, just to make sure my new one is the right part.

Also says my rear U joint is Shot to hell.

 

I have a slow drip on the fuel tank, Pinholes around a circular stamping in the front of the tank.

Do they make a spray on epoxy for this type of problem? Something like flex seal for fuel tanks?

 

I will test it.

My feeling is that it is not charging the ING lite on the dash is on when the engine is running

The alt on my 1.6 was less than a year old how about just swapping it to the 2.0L or is it more complicated than that.

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the L16 35amper 521 is a external volt reg alternator anf the 521 is wired for this.

 

Your L20 I assume the alternator on this is a internal volt reg type. You could get it tested and if good then convert your 521 by doing the jumpers on where the old volt reg would plug in.

 

or just use the old L16 alternator and just plug it in but Im not sure if the bolt holes are the same on the ears of the alternator.

 

 

Im thinking your double regulating it if your using the newer 70 IR type alt and then using the old volt reg on the 521.

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When you mix stuff up from different years it causes issues, the clutch issue is likely that you used the clutch pedal assembly that was on the transmission when you put the 79 620 engine/flywheel.clutch cover in your truck, that throw out bearing collar is taller, so once you got the transmission mated to the engine, the clutch was always being pressed in, this is why when you loosened the transmission from the block, it started working correctly, all you should have to do is put the correct throwout bearing collar on the clutch fork, and it should work fine, unless you ruined the clutch cover when you bent one of the diaphragm fingers, personally I would just buy a new clutch cover and have the mechanic install it and be done with it.

The reason I say this is because if that one finger is not even with all the other diaphragm fingers and sticks up even an eighth inch higher, it will be hitting the throwout bearing all the time, which will eventually smoke/ruin the throwout bearing, and it will have to be pulled apart again.

 

If the alternator was on the 620, it was likely an internally regulated alternator, but your 521 wiring harness is made for an externally regulated alternator, so it's not going to charge until you jumper wire the voltage regulator plug, see the green wires in the photo below, you will likely have to do this.

DSCN1040.JPG

Here is a diagram on what wires need to be connected to what wires.

wiring_diagramIR.jpg

The voltage regulator is on the inner fender just forward of the the fuse block, not sure what color it would be, as mine was an aftermarket digital type, and it is/was black.

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Wayno,

I am really confused.

"that throw out bearing collar is taller,"

I believe the 620 collar is taller and the 620 bearing face is bigger in diameter than the shorter 521 collar and smaller in diameter 521 bearing.

Are you saying I should have used the original 521 (shorter) collar and (bigger diameter)620 bearing?

Because that is not what I understood too do.

I just ordered a new 620 collar and bearing already assembled from rock auto.

I went down to the trans shop and and the one I ordered appears to be the same one as out of the 620.

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NO, the 521 collar is taller that the 620 collar, and the 720 Z24 collar is very short, the reason is that the 521 has the shortest height clutch cover(200mm), so the collar has to be taller, the later 620 uses a 225mm clutch cover, it's a little taller(or maybe it's better to say it thicker), so the collar is that much shorter, while the Z24 engine uses a 240mm clutch assembly(taller/thicker), so it has a very short collar.

The transmissions are all built the same, it's basically the same bellhousing in all of them, so if a larger clutch is used, the collar gets shorter.

If your using a L20b out of a 620 with a 225mm clutch cover/disc, you need to use the 620 collar made for that clutch assembly which would be the middle sized collar, the collar follows the clutch assembly, if you were to ever go to a 240mm flywheel/clutch cover, you will net that collar, as it is a set, 521 sets, 620 sets, 720 sets, and roadster sets.

Wayno, I am really confused. "that throw out bearing collar is taller," I believe the 620 collar is taller and the 620 bearing face is bigger in diameter than the shorter 521 collar and smaller in diameter 521 bearing. Are you saying I should have used the original 521 (shorter) collar and (bigger diameter)620 bearing? Because that is not what I understood too do. I just ordered a new 620 collar and bearing already assembled from rock auto. I went down to the trans shop and and the one I ordered appears to be the same one as out of the 620.

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