1973 620

[EBW]

The vacuum line is correct. did u check the distributor pedestal for the timing as mentioned above?

 

 

I have been at work and haven't had a chance to work on it.  But I will be working on it Wed and hope to have an update.

[distributorguy]

Check the timing.  

Pull your spark plugs:  if a rocker has come off, you will have 1 plug different in color from the rest, plus a LOT of rocker noise.  1-3-4-2 firing order - if that's wrong it'll backfire too.  

[Pacific coast Datsun]

The L motors are fairly basic & easy to troubleshoot. Good info guys !

[EBW]

Hope to have an update on engine today.

 

 

In the meantime, Question to all here. 

 

I read somewhere there is a Good vs not so good Brand for Wheel Cylinders.  I plan to change them all out due to the time the truck has sat dormant.

Any help in Brand and possibly a product # that I can order ??

 

ALSO...  Wiring Looms.  The wires are making me worried.  It took a full minute for the lights to come on after pulling the headlight switch.  No idea how the rest of the truck wiring is.

Is there a company that makes NEW Wiring Kits for the 620 ???   

 

Thanks again for all the Help here.  Your info has been invaluable !

[red13]

No new wire kits, i opened my loom up just to check wires and fix the POs botch job. On my fb page i did a write up for light switch disassembly and cleaning.

[EBW]

Not much of an update. 

A bit lame on my part, but I am having a hell of a time finding the Timing Mark on the Crank Pulley. 

 

I have been slowly cranking over the motor with the Coil Wire off and cleaning the pulley off as I keep looking.

Is it a V Notch ?  Or a Line ??  If it was painted, Its long gone.

 

I looked in my service manual and there is no picture. 

On my other vehicles it is obvious, but I swear I can't find it on this one.

 

I will search on here and the internet for some info.

[Draker]

It's just a slight notch on the side of the pulley. 

[Draker]

Here it is on my L16

 

[red13]

Here it is on my L16

 

Could you enlighten me on the timing here,  this little notch is for? while the degree indicator on the other side is for tdc?

[EBW]

Well....   Datsun 1     Me 0

 

Found what appeared to be a notch on the pulley and marked it.

Set up the timing and it is pretty close to where it should be.  Runs and idles fine, but it still pops through the Carb....  WTF !!???

 

I ran it with and without the Vacuum hose attached to the Distributor.  It did not change anything.

 

I am done for the day.  I am thinking its much more than the timing.

 

Next will be pulling valve cover and maybe head depending on what I find.

I didn't want to pull the motor, but it may have to come to that.

 

 

Thanks for all the help fellas!  The journey will continue at a later day and time.....

[Pacific coast Datsun]

The valves may be out of adjustment causing the backfire. Theres a cold & hot setting for the valves & that info is in the Chiltons or Haynes manual but off the top of my head it's ...Hot- Intake .08 Exhaust .010....Cold Intake .010 Exhaust .012. Also theres lots of info here on how to adjust the valves....very easy.

[Draker]

Pull the valve cover, put engine at TDC. You'll know because the cam lobs at #1 will be at 10 and 2 o'clock. Also the timing mark on the crank will be at TDC. Look at the cam marker (should be lined up) and check the distributor tang is at this position. (credit DM)

 

 

 

[Draker]

As mentioned, check the valve clearance and adjust.. Then reassess if it's still back firing.

[banzai510(hainz)]

ck for loose distributor bushing get new condenser.

 

I would ck the timming chain as mention above. I had almost 200k on one motor and it just needed all the above.

[EBW]

Not much to update.  Holidays and Family took my time.

Parts have been showing up... A New grill and door mirrors.

 

The new Grill is ( i believe ) a later model one.  There are no Headlight "surround eyebrows" plastic like the original. 

Just the round cutouts for where the headlights go.

A little upset since that is what gives the 620 a certain look.

 

If I can find a earlier grill I will either sell this new one or make it wall art.

 

Now that the snow and sleet has stopped, I am getting back into the motor and seeing if I can get it running smoothly.

 

Thanks for the help fellas. 

[NeckBrace]

What kind of door mirrors did you get? I'm on the market for some, but can't settle on a pair!

[EBW]

I'll post a pic once I get home. I saw them on the "mirror thread" that was floating around last month and ordered off of eBay.

[EBW]

Just a little update.  Pictures of the new grill.  Is this a true 620 Truck grill for a later year ??

I installed the new one... although i prefer the look of the original.  May do a major overhaul of the OG one.

 

 

 

 

 

 

The new mirrors I purchased off of Ebay...  Taiwain.

 

 

 

 

 

 

The quality of these mirrors.......   Don't waste your time or money.

 

 

 

[EBW]

Update.  interesting situation and I am curious what you all think happened.

 

 

Took Valve Cover off and took a look at everything.  I was surprised to find #2 and #3 exhaust rockers very loose, with #2 completely off !!!  See pic.

 

Well, started to adjust valves and noticed something was missing...  OH crap !!!  Well I found the one part quickly, the second piece not so much.

Many thoughts went through my mind thinking the worst.. that it was at the bottom of engine or chewed up. 

I was able to find the second piece hidden between two valve springs and was able to get everything back to normal conditions.

 

Valves were adjusted as specified and I fired it up.

Success !!  Runs like a top !!

 

What I think happened is the two exhaust valves were stuck and allowed the rocker to come off the cam lobe.

That also explains the backfire through the Carb. So I am happy to say its fixed and Datsun made one hell of a motor to take abuse and keep on running.

Now to get the fuel tank out and cleaned up along with the fuel lines.

 

 

 

 

Next will be the brakes. 

I saw a post that some of you have preferences on the wheel cylinders. Good and bad.....

Any comments on the brands and places I can find them?

I am all ears.

 

Thanks for reading and following my (slow) progress.

 

 

 

 

 

 

 

 

 

 

[datzenmike]

Take valve cover off and look at the rockers where that meet the valve spring. You may have dropped a lash pad and the rocker popped off. Likely an exhaust.

 

Sure nailed that one!!!

[EBW]

Sure nailed that one!!!

 

 

Yes you did !

 

Now, any recommendations on Wheel cylinders ?? :thumbup:

[distributorguy]

Rockauto has the genuine Japan wheel cylinders cheap.  

[EBW]

Rockauto selections for wheel cylinder

 

Centric..

Beck..

Dorman.

Bendix..

EIS...

Wagner...

 

Those are the options.

Centric states they are preferred. Any truth to this ?

 

Thanks for the help fellas.

[banzai510(hainz)]

rockers fall off every now and then . if you loose a cylinder ck sparj plug ,wire then lash pad fell off.

[EBW]

Update.

 

I ordered Centric brand wheel cylinders, drums, hydraulic hose and pads.

 

Should be on the road soon.