My Dad's 620 parked for over 20 years

[620owner]

I parked my dads 620 in the garage in 1994 when he became ill. Dad died in 1995 and the truck hasn't moved in over 20 years. I've decided that it is time to put it in the road again. The odometer shows 41,000 miles and seems to be in pretty good shape. 

 

I started out changing the oil and filter.  Replaced a few things. New fuel pump, water pump, carb (Hitachi... I know but i wanted to keep it original), spark plugs, wires, distributor cap & rotor, Picked up a matchbox distributor (E12-80) and replaced the master brake cylinder and battery. Checked compression and had 160 lbs on all cylinders. Good to go ...

 

Ok, filled the tank with gas (added some sea-breeze). I placed an electric fuel pump and fuel filter ahead of the mechanical fuel pump and used the electric pump just to prime the system. The carb filled up to the dot in the fuel bowl window. I hit the key and she fired right up. The engine ran OK for a few minutes at high idle but then ran ruff at low idle speed. Checked the timing, it was on zero, bumped it to 5-BTDC, readjusted the carb idle screw. The engine acted like it was leaning out, checked the carb gas was still on the DOT in the window. After warming up the engine didn't want to idle and bogged some when increasing throttle until RPM's were up and then it would run ruff at high speed, almost like it was retarded timing but it was right on. Ran it at high speed for a while it would sputter a little hearing a little backfiring in the exhaust like it was running rich...... this thing is crazy. I pulled the plugs and they were a little dark and getting dirty but all were firing. Checked vacuum, gauge showed steady normal vacuum. So the engine doesn't want to idle and is acting like it's off timing but shows right on when checked. Carb has good gas, no vacuum leaks and plugs are firing. Well that's where i'm at .... any help would be appreciated.

 

I have pictures and video but can't figure out how to post them. Help on that would also be appreciated.

 

Maybe should have posted this in the engine forum..

[banzai510(hainz)]

idle jet plugged or mixture needs adjustment.  from junk in tank.

 

remove the fuel filter and cut open and inspect it to see if a lot of rust and dirt.if so then carb but be plugge idle jet

 

Really I would run some carb cleaner thru it first and rev ethe shit out of it and put a Rag on carb to sucks the jets clean if possible

 

 

olddatsuns.com tech section

[Ericthenorse]

I spent a while messing with my friend's 520...   We traced it down to the ballast resistor by the coil.... Try swapping that out and see if it works better...

[datzenmike]

Timing for the L20B is 12 degrees BTDC.

 

If you have a real Matchbox distributor you need to get the matching EI coil for it and get rid of the ballast resistor. If running the stock coil and ballast you are only getting rid of the points. With the ballast removed and the right coil you will have much hotter spark.

 

Engine may be warmed up but did the choke turn off? Take the top off the air filter when running warm and look.

[herculesinwyoming]

Yep ballast resistor needs bypassed for sure

[620owner]

Thanks for the replies. I haven't jumped out the ballast resistor and still running the stock coil. Yes, the choke as wide open. I'll make those changes. 

[620owner]

Also, I'd like to post a couple pictures and I also made a couple video starting it up but can't figure how to post them .... a little help would be appreaciatde on that too.

[KoHeartsGPA]

For pictures upload photobucket app, and when you click on a picture from bucket, select share with, select copy link to clipboard, select last option, paste on forum.

 

For videos, create a YouTube account, upload to there, then copy and paste link to forum.

 

Welcome to Ratsun!

[620owner]

Photo of 1977 Datsun 620

 

 

http://s1016.photobucket.com/user/rlvega/media/IMG_20150812_160437737_zpsbyk86shr.jpg.html?o=0

[Draker]

Use the IMG code to post:

 

 

[Draker]

Looks like a nice truck!

[620owner]

Video of first start after setting 20 years.

 

 

 

http://s1016.photobucket.com/user/rlvega/media/Mobile%20Uploads/Engine_Startup_zpsgjsalieo.mp4.html?o=0

[datzenmike]

Thanks for the replies. I haven't jumped out the ballast resistor and still running the stock coil. Yes, the choke as wide open. I'll make those changes. 

 

Just saw this. You can only safely remove the ballast resistor IF you replace the stock coil with an EI coil. Otherwise the EI unit will draw too much current through the stock coil and burn it up.

[620owner]

This is the EI distributor. Hope it's the correct one.

[620owner]

Haven't had a chance to work on the truck but wanted to make sure I have the right distributor for the 1977 engine.

[620owner]

The top side.

[620owner]

Had some time to work on the truck.

Voltage readings with ballast resistor jumped / not jumped.

 

 

 

Looks about .7 of a volt difference. Not much of a drop across the resistor. I ran it for awhile the coil didn't seem to get any warmer jumped out.

[620owner]

I went through the valves. Adjusted them .008 and .010 with the cam lobes at 10 & 2 o'clock. I did see some slop in the timing chain. The engine has 41,000 miles..... Check out the video guys, it's not noisy. The timing is rock solid  (not bouncing around) .  Checked the vac advance after I timed it, and it is pulling working fine. Let me know if you think it should be changed.

[620owner]

I adjusted the carb, air and idle. Also set the timining at 10BTDC and it runs smooth at idle now and is very responsive. Thanks for all the tips. Any other suggestions would be great. Many thanks again, love the forum.

[banzai510(hainz)]

keep the coil and ballst in there if that was stock

[datzenmike]

E12-80 is the correct module.

 

Yes it's a '79-'80 EI distributor. If you give me the numbers off the side of the casting I can tell you exactly what it's from. 22100-?????

 

Check the coil. It should be the EI coil to work with the EI distributor. If it isn't, get the right one ('79 200sx, A10 or 620  truck will work) and you can get rid of the ballast resistor and have higher output spark.

[cruznude]

very nice. one of the better ones. looking so cool already and stock. That's what the 620 was meant to do when you saw it. I love the 620's. 40 years later our kids, friends, are all at ah that were restoring these trucks and having fun. They just don't understand. 

[620owner]

I have a question about the Carb. I've noticed that after the engine is shut down the gas in the carb bowl goes down. It looks almost empty when I look through the bowl glass. Shouldn't the gas level in the carb remain high at the DOT level when the engine is off even though there's no fuel pump pressure ?

[banzai510(hainz)]

does the carb have a return line?  maybe it drains out thru that but Im not positive. Seems to me it should stay with in the line.

 

 

If truck runs fine don't worry about it.

[620owner]

The truck runs fine. There is a return line. When I run the electric fuel pump it circulates. I don't run the electric fuel pump I only put it ahead of the mechanical pump to prime the system and fill the carb on initial startup. When I turn the engine off I can see very small bubbles and the fuel level does slowly drop down, I can see the float. I can't understand where the gas is going. The fuel line is in the top of the carb, it can't defy gravity or can it ..... I know what some guys in the forum would say, "put some duct tape over the window and forget it". Good old duct tape ! But seriously it doesn't make sense that the carb would empty and have to refill on every startup.... does it ?