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Justin620datsun

New to me 620

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4 hours ago, datzenmike said:

 Electric pumps were used on '79 air condition or camper trucks.

 

3rd time lucky, maybe ?

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Jeff Hino got one from a 79 also a electric distributor.

 

Look like a Faccet pump to me.

 

Nice truck. I would preety much just leave it. Lower it if you want.

Edited by banzai510(hainz)
spelling

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Ok. I dont plan on doing anything major to it just making it more...daily driving friendly.  Anyways today...I got off work drove home and my truck has been "dieseling " since I got it I cleaned the carb out and adjusted the idle and it helped a little. But today it backfired and almost gave me a heart attack.  Not the first time I've had a truck do this though. Where do I start to fix it? The gas attendant didn't find it very funny...?

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is stock carb or stock?

most weber aftermarket carbs dont have a anti desieling selinoid so the idle jet is not closed when shutting down thus sucking gas in and a hot open chamber is prone to detonation. stoch Hitachi carb have this.

 

back fire? I would try to adjust the timming. see wht it is and back it down a little bit.

if a weber carb there is a mixture scre on the side at the base. one can turn it in or out and the motor will have a sweet spot.

 

 

this is just me, on a hot day I will rev the motor up and take a small cup of water and drip water in the carb and rev it so it dont shut off and give it a piston cleaning.might help clean the carbon.

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I believe its a stock carb. And the timing might be off I'll look on here to find a way to tell. Also the water trick I did it to my 79 Toyota pickup I had when it did the same thing and it fixed it. I'm unsure of the timing situation and I dont want to mess it up to where I can't put it back. I'll do some research.  

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theres a 10mm bolt under the dist. just loosen it and rotate the dist to get the timming where you want it.   I run a little more adavance but really best to run Super on a Open chamber head.

 

watch my "you tube" to cheak on timming chain timming

Edited by banzai510(hainz)

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So I'm looking to replace the ignition switch and maybe the wiring to it. Sometimes my truck wont start but if I wriggle the plug it starts. Any brands or companies you guys recommend? 

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Also I took this today forgot to post it earlier.  Passenger A pillar. So someone must have switched it to the fender? The fenders are in decent shape maybe put on from a different truck by chance? 20181021-170210.jpg

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The '79 is the only 620 with the aerial on the driver's A pillar. I don't know what to say to this other than it doesn't really matter much. I had a '78 that was rolled and put a '74 cab on it. 

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ck the plug in back of ignition switch. some times they just dirty. Don't replce wiring. Clean clean them up first.

 

what makes you think the switch.?  If don't start (seliniod clickingand you swapped the starter already  one can wire in a hot start relay.

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Little update. Cleaned up the plug(spider webs and dirt) now seems like start fine. I'll be doing plugs and wires in a few days. And brand recommendations for those? I heard ngk for plugs? I love the looks I get in this thing. I'll mess with the timing as well to get it running better. I also found some hoses that are "plugged" under the air cleaner should they be plugged in somewhere? They are plugged with bolts. I'll get pictures when I get off work.

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get photos. Some OK to plug others not esp the crank case vent tube

NGK wire setNE 64 plug wires, NGK B6  or Nippondenso plugs and if possible get the Standard Motor product dist cap with the brass contacks. Rock auto has photos and part number. Thry used to sell the zBlue streak Version with Copper but cant find anymore. I run them and had them for 8yrs on same motor

Edited by banzai510(hainz)

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Ok so little update. I checked out those hoses that are plugged off. They connect to the air cleaner. What are the sensor looking pieces under the air cleaner lid? I tried looking it up but came up with nothing. They aren't connected to anything.  And I will be getting spark plugs later this week. 

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Idle is WAY too high. Should be 650-750.

 

That high it's not running on the idle circuit which has a solenoid that shuts off the gas with the key. This solenoid controls only the idle.

 

In the air filter snorkel is a vacuum powered servo motor that opens and closes a flap gate door against a spring. This door mixes cold air from in front of the rad with warmed air from the hot exhaust. The intent is to provide the engine with a tightly controlled air temperature all year round. The engine warms faster, runs better and gets better mileage if the air temp is constant. It also eliminates carb icing in cold damp weather like freezing rain.  During full throttle the intake vacuum drops and the door closes off the heated air and only cooler outside air is drawn into the engine for full power.

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A vacuum leak would make it run poorer.

 

All you need is the vacuum advance for the distributor and I would keep the ATC (auto temp control) on the air filter working, or get it working. The EGR you can leave disconnected.

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Ok sounds good thank you. So another question.  If I get the timing dialed in and it doesn't stop the dieseling what's my next step? I heard seafoam but I don't know if I want to do that.  And also I adjusted the idle and it made the dieseling less...violent. again I got gas today and the attendant about jumped out of his socks.  How do I check what it is idling at? You said 650-750? How do u measure that? 

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Does the VIN number on the title match the VIN plate on the door or in the engine compartment? If not it's the wrong title for the truck.

 

Since there are antenna mounting holes on the passenger side it could be a 78 or earlier cab/truck vs. a 79.

 

The AC rubber delete plugs are still in the firewall, and there is no AC Drier or bracket on the passenger inner fender. There are no monster cast iron AC brackets on the engine either.    This truck/cab probably never had AC. But it is possible the cab was swapped as DZMike said. 

 

I don't know why it would have the stock electric fuel pump without  AC, unless they did a really fantastic job of removing all the elements, and putting back all the delete rubbers/plates?   Are there center vents in the dash, or does it have a radio or a delete plate? Post a picture of the dash. 

 

Is there a condenser (skinny looking radiator ) mounted in front of the radiator on the grill side of the radiator support bracket?  The 78 and 79's with AC had an 8 blade fan vs. a 7 blade fan on the trucks without AC. How many blades on your plastic fan?

 

FYI:  Datsun AC was installed on 620 trucks as early as 1978 either at the factory or at the dealer (and the 78 had the Datsun electric fuel pump like that one,) possibly back to 1976. I researched this once and can't remember what cut off date I found.

 

There is an AC section in the 78 Factory Service Manual, but I don't have a 77 or 76 manual to check if there is an AC section in it.

 

Does anybody have a 76 and/or 77 Datsun Factory Service Manual who can tell us if there is or isn't an AC section in it?

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There's a delete plate above the "switches" for the heater and such. The radio was mounted on the center console in front of the shifter with a small delete plate as well. I'll take a picture when I get home. 

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