79 datsun carb

I have a 79 datsun pickup 620 , 5 speed had a idle problem a couple months ago and found out it was the EGR passage system and is running good, but now the secondary barrel on my (factory) carb will not open. I was wanting some info on what kind of carb i need to buy and where is a good place to look for one. Priced a couple at the auto parts place and just wanted some more experence in the whole situation. Also i talked to a guy who has the same truck a year older and he told me that he put a Weber adaptor and a header and it made all the difference in the world. so carb and a header is what i am needing.
Thanks in advance for helping.

weber is the only way to go man a new one is going to run you about 550 bucks but i have found rebuilders at the local wrecking yards for 75 bucks and the rebuild kit for around 45...and its an easy rebuild

the weber is the only way to go!

what state do you live in?

in CA a 79 still has to be smogged, so that would limit you on carb choices.

if your truck has a L16, a weber 32/36 DGV and a header would make it rip, but if you have to smog it you are probably limited to a weber 32/34 DFT, a smog-legal weber, it definitly won't give you as much performance as a 32/36DGV but will be a huge improvement over stock.

IMO, it isn't worth wasting money to repair or replace the stock carb, they are junk. get the weber.

below is a link to Top-end Performance's website, they sell weber carbs and conversion kits. they are some very good guys over there, i get most of my weber stuff through them.
http://www.racetep.com/

the weber is the only way to go!

what state do you live in?


i live in NC so no worry about smog or anything like that. Also do i really need that egr passage for that truck? i dont know exactly what egine i have. AIn my book it says Datsun Pickup 620 series 119.1 cu. in
(1952 cc) och maybe you could tell me a little more about that?

i live in NC so no worry about smog or anything like that. Also do i really need that egr passage for that truck? i dont know exactly what egine i have. AIn my book it says Datsun Pickup 620 series 119.1 cu. in
(1952 cc) och maybe you could tell me a little more about that?
you have an L20 which is a 2000cc engine

yea, you have a L20b
wikipedia on datsun L-series engines
http://en.wikipedia.org/wiki/Nissan_L_engine

i have a L20b in my 510.

it has the same manifold flanges as a L16 or L18 so you can use the same manifolds as a datsun 510 on your pickup
basically any 510 (datsun L-series) intake manifold will fit, some headers will fit and some won't because your truck has torsion bar front suspension which is different from the 510 setup.
also some later model pickups used a round exhaust port L20b head (instead of square ports in earlier L-engines) the intake ports are still the same so the 510 intake manifolds will still work with this head, but 510 headers definitly won't work with it.

i am running dual sidedrafts on my L20b
http://files.automotiveforums.com/gallery/watermark.php?file=/503/385373afmy510e.JPG
but this is more of a race setup and isn't really street tame/legal

for everyday street-use i would still reccomend a single downdraft weber 32/36 DGV. you can still use your stock intake mani with a spacer/adapter.

if you don't need to smog it you definitly don't need that EGR. try and get stock intake and exhaust manifolds from a non-EGR L-series. all it does is rob your power by feeding the engine burnt garbage air.
i actually have a few non-EGR intake manifolds if you can't find one in a junkyard.

well i have looked in junkyards all over NC(with the internet and personally) and everyone tells me that they have crushed evrything with that year and earlier. I have found to be hard to find parts for that truck. If you would like to sell your intake i would possible be able to purchace it. You could PM me a price.If you like.

you have a PM

damn, that sucks man. over here, on the west coast, old datsuns are rare at junkyards, but we still have some. in NC the climate probably took its toll on the bodies of your datsuns which is why they are so quick to crush them over there.

70's datsun pickups are fairly common here, i see them still on the streets all the time.

yea you really dont see many over here on the east coast. That is one of the reasons i like it so much.also looking for a exhaust manifold

does your head have round exhaust ports or square?

on your head on the side where your sparkplugs go, right above where the head meets the block there should be a casting number (a letter and two numbers) does it say W58?

all i have left (besides what is on my car) is a stock 510 (squareport non-egr) exhaust manifold.

you should check ebay, but make sure you know which ports you have.

does your head have round exhaust ports or square?

on your head on the side where your sparkplugs go, right above where the head meets the block there should be a casting number (a letter and two numbers) does it say W58?


yes it says w58

yes it says w58

you have round exhaust ports

i have a datsun head out in my garage that is a w58 head and it is a roundport l20b head.

sorry, but like i said in the email i had a header for that, but i sold it this summer.

i did a quick search on ebay and this is what you are looking for
http://cgi.ebay.com/ebaymotors/DATSUN-NISSAN-620-720-PICKUP-HEADER-4WD-26640_W0QQcmdZViewItemQQcategoryZ33631QQitemZ80255 45757QQrdZ1QQsspagenameZWDVW

edit- i got your reply email tonight, but i'll get back to you on that tomarrow morning, its getting late

until then here is something cool that i found when i googled datsun L20b horsepower, scroll down a bit and there is an article about a L20b swapped datsun 1200, running 31 psi of boost for 411 hp.
http://datsun1200.com/modules/nsections/index.php?op=printpage&artid=69

DIME you dont know how much your help is appreciated and has made things a bit easier for me. I will prolly get some pics on here tomorrow of my truck and the engine prolly make things easier for you. (help you help me) and also will have good "before and after photos". Im thinking about getting some of my brackets and valve cover chrome dipped Along with a couple other items. Dumbass me i guess like alot of others is fix the engine and run out of money for the body lol But in all honesty the body is in good shape.

Also with all the engine upgrades that im doing do i need to look into the suspension?

no problem, glad to help. can't wait to see pics of your truck.
pictures of my current datsun project are in my member gallery
http://files.automotiveforums.com/gallery/showgallery.php?ppuser=385373
i haven't gotten mine painted/bodywork done yet either

i think the next thing you should think about is brakes. you may want to do some suspension work later, but make sure you can stop first. on the site below i read that later model 620's came with front disc brakes and electronic ignition standard. do you have front discs?

i googled datsun 620 and this came up, you probably have allready seen it, but here is a link anyway, lots of info and some good links on site
datsun 620 link
http://www.worldaccessnet.com/~dcmurphy/620/620.htm

this one has differences in 620 production years.
http://home.sprintmail.com/~cathbrown/doug/pickup.html

hopefully i will get some pics up this weekend i have been swamped at work the last week has also put a halt to my project for now. 11-13 hours a day. "killing me" lol but deffinatly get those up this weekend. Also DIME a guy at work has a 1980 720 Datsun will my exhaust header bolt on his?
Also when i put the mechanical fuel pump on my truck will i need a different cam? im assuming after i put the mech fuel pump on i can just block the other lines off?

hopefully i will get some pics up this weekend i have been swamped at work the last week has also put a halt to my project for now. 11-13 hours a day. "killing me" lol but deffinatly get those up this weekend. Also DIME a guy at work has a 1980 720 Datsun will my exhaust header bolt on his?
Also when i put the mechanical fuel pump on my truck will i need a different cam? im assuming after i put the mech fuel pump on i can just block the other lines off?

this is a quote from an article on-line
1. Description
The 1980 model featured the L20B engine which essentially was a carryover from the 620 model trucks that preceded the 720. It was a single overhead cam engine displacing 2 litres. The 1981-1986 models had the Z series carbureted engine which featured a single overhead cam operating adjustable rockers, crossflow head and dual spark plugs for each cylinder. 1981-1983 models had 2.2 litres of displacement designated Z22 while 1984-1986 had 2.4 litre engines designated Z24. 1984-1986 models had computer controlled carburetors with an oxygen sensor in the exhaust manifold.
original article link-
http://www.off-road.com/nissan/720faq.html

as for the header working or not, look for the head casting number on his engine, if it says w58 or n56 it is a roundport head and will use the same type of header. i can't say for sure if the suspension has any major differences that would cause interference, but i really doubt it. they are probably interchangeable. is his truck 4WD?

datsun cylinder head id page-
http://www.worldaccessnet.com/~dcmurphy/620/tech/head_ID_2.htm


the mechanical fuel pump runs on a eccentric washer that is on the cam sprocket bolt, you don't need another cam, but you may or may not have this washer. these were put on during initial engine assembly and are often on cars that don't use them. also there is a small spacer that goes between the head and the pump that may or may not have been put on your engine even though it did not use it stock. (i can email you pics of either if you need help identifying them)
yes, with the mech pump, you just need one supply line and that's it. you can block the other off. make sure you get a good seal, you don't want fuel leaks.

can't wait to see those pics of your pickup.

yes please send some pics if poss. i took the valve cover off and really didnt know what i was looking for. i see it has washers and some kinda spacer on the bolt that holds the timing sprocket and bolts it to the cam.

got your pics and now i know that i dont have thef washer that you are talking about. Is that something that is going be a search or a local parts store item? I have a feeling it will not be that easy!!! :nono:

if you can't find them in a junkyard, nissan is probably the only source for new ones, if they even have 'em anymore. it's not something that would ever need to be replaced, so i doubt it will be available through your local auto parts store.

which part don't you have, the pump spacer or the eccentric washer? (both?)

i might have a fuel pump eccentric loose some where in my garage, i'll take a look. i know that i don't have any spare fuel pump spacers.

if you can't find them in a junkyard, nissan is probably the only source for new ones, if they even have 'em anymore. it's not something that would ever need to be replaced, so i doubt it will be available through your local auto parts store.

which part don't you have, the pump spacer or the eccentric washer? (both?)

i might have a fuel pump eccentric loose some where in my garage, i'll take a look. i know that i don't have any spare fuel pump spacers.
i think that the spacer is on my truck. i dont have the eccentric washer that bolts to the timing sproket. I, hopefully will get those pics tomorrow and post them. also i have decided to take the egine out. any helpfull hinters you could through my way i could put them to use.

i found a fuel pump eccentric that i can probably spare. i'll throw it in the box with the carb for $5 more.

engine removal tips (starting with the obvious, moving towards the more specific)

this process has become almost automatic for me . . .. it is fairly easy.

use some masking tape and a shaprie and label all of your wires and hoses with where they connect to before disconnecting them. makes it much easier for reassembly.

get a bunch of ziploc bags and a sharpie and separate all of your removed fasteners and label where they go on the bag. this is again to help with reassembly and to prevent any lost fasteners.

a little extra time spent on being organized before tearing stuff apart saves alot of time trying to figure out how it all goes to back together.

use your manual . . . sometimes there is usefull info in it. (lol)

drain all fluids before trying to pull engine. (can get really messy really fast)

there may or may not be a flywheel covering plate installed on your truck. this is a two piece cover, make sure all fasteners are removed and the bottom piece is completely removed before trying to separate your engine from your trans.

remove all accessories and radiator etc. make as much room for yourself to work as possible, also prevents damage to your engine and other parts.

if you take your time and are carefull, removing the engine can be done solo. re-installing it will take atleast 1 other person, preferably two.

i attach the lift chain to one of the rear manifold studs and one of the fuel pump studs.

when unbolting the motor mounts, remove the two small bolts that hold the mount to the x-member, not the large ones that connect the mount to the engine. (leave those on, remove engine with mounts) this makes it easier to re-install.

use a floor jack to support the transmission (bell) as it will want to droop when the engine is removed.

that is all i can think of off the top of my head. like i said, the whole process has become automatic for me, so remembering steps and tips is kind of hard. it is an easy engine to pull, i'm sure you won't have any problems, but if you do, go ahead and post or email me.

there are some tricks to re-installation, but we'll talk about it when you get there. right now i have to go help my non-mechanically inclined brother change a tire. talk to you later. good luck.

edit- why did you decide to pull the engine? (just curious)

the biggest reason is to just do it!!! lol like you said i have the fever, plus i want to get it cleaned up. get the grime off of it and paint the block and all. I work at a metal fab shop (welder) with a paint line so im going to power coat the valve cover and all my brackets and so forth. also i was taking off some stuff today and their is a wire that hooks to the starter slyd. and then threads into the block and i bearly touched it and of course it broke dont know what that is going to look in my book now. maybe you know what it is?

sounds like someone tried to run a ground wire from the solenoid to the block. this isn't needed because the solenoid grounds through its body into the trans. the wire was brittle because it probably burned when it was first started. starters pull lots of amperage and the wire couldn't hold that kind of current and just burned up. it probably wasn't doing anything anymore anyways, so it shouldn't matter later when you go to reassemble your truck.

do you have a digital camera?
can you snap a quick pic of the wire in question and email it to me?
(makes diagnosis easier and more certain)

what happened to the pics of your truck?

another thought on your engine pull-
if you have a digital camera, stop and take pictures as you go along. not only will this give you a cool record of progress that you could post, but it could help in reassembly.

sorry about the pics i have a camera but the usb cable isnt working prolly going to get a new one soon but what im trying to do is set up a computer in the garage and web cam the install. I have already got the engine out. To be honest it really wasnt that hard. i labeled everything. I think the wire that i broke is some kind of sensor? maybe a oil pressure. After relooking i can not say that it is directly hooked to the starter syld. I have 2 books one is a haynes and the other is the shop manual, and im missing some pages i think the pages i need ( what luck)
Also on the drive shaft the bearing that bolts to the cross member and hold the shaft in place is trashed. Ill have to see what i have to do to replace that? Hopefully we will get this set up soon.

Also one mistake when i pulled the engine out ( really funny) I forgot to drain the tranny. Now i have a big ass pool of gear oil in my friends garage lol What a "noob alert"
Speaking of the datsun fever I think it is contagious because my friend is all ready looking on ebay and auto trader ect. for a datsun 280Z project car. I dont really understant it because he has heard my call my truck everything but a truck. LOL

the wire, did it run to a sensor/plug in the side of the block under the sparkplugs and to the left of the oil filter?

that wire is for the stock oil sensor. it was just a warning light on your truck, right? you will probably want to repalce that with an actual oil pressure gauge. you could probably get a cheapie/universal at your local auto parts store for about $20-$25.

oil pressure gauge > zero oil pressure warning light

good to hear you are making good progress on the pick-up.

pictures?!?

the wire, did it run to a sensor/plug in the side of the block under the sparkplugs and to the left of the oil filter?


pictures?!?


thats the one! :)

Hi,

I am the other infected party :biggrin:

There is only a warning light now so I figure he'll go for the gauge as it now sounds like he's considering replacing the head gasket as well. :uhoh: :lol2:

Pics should be up tomorrow and hoping to get a web cam going for the install.

http://img66.imageshack.us/img66/4153/10006969mg.th.jpg (http://img66.imageshack.us/my.php?image=10006969mg.jpg)

http://img66.imageshack.us/img66/8259/10006980gu.th.jpg (http://img66.imageshack.us/my.php?image=10006980gu.jpg)

http://img77.imageshack.us/img77/641/1000697s0kt.th.jpg (http://img77.imageshack.us/my.php?image=1000697s0kt.jpg)

http://img81.imageshack.us/img81/2927/1000700s9fj.th.jpg (http://img81.imageshack.us/my.php?image=1000700s9fj.jpg)

http://img66.imageshack.us/img66/3001/1000686s6pl.th.jpg (http://img66.imageshack.us/my.php?image=1000686s6pl.jpg)

http://img81.imageshack.us/img81/1162/1000706s1py.th.jpg (http://img81.imageshack.us/my.php?image=1000706s1py.jpg)

http://img74.imageshack.us/img74/6889/1000689s3vh.th.jpg (http://img74.imageshack.us/my.php?image=1000689s3vh.jpg)

http://img78.imageshack.us/img78/7030/1000692s9qg.th.jpg (http://img78.imageshack.us/my.php?image=1000692s9qg.jpg)

http://img66.imageshack.us/img66/4131/1000704s8dy.th.jpg (http://img66.imageshack.us/my.php?image=1000704s8dy.jpg)

Took awhile but we finally got em.

Transmission is now off and engine is on an engine stand. It also got pressure washed yesterday and is much cleaner.

nice truck.

the body looks to be in really good shape.

after seeing pictures of the engine, i can now see why you wanted to pull it. that is one dirty bitch.

sorry it has taken me a few days to respond, i just got a new 8 - 5 job and i'm still getting used to getting up that early.

sirchexxalot, welcome to AF and the Datsun forums!

glad to see you guys are making good progress, keep me updated!

well, i've got to go to work, talk to you later.

Thanx for the welcome :)

I have a 240SX and have been trying to decide what I'm going to do with it and have gotten some good advice from the forums there as well.


We had an "off" day today as Toke had some things to take care of. I should be posting some pics of the cleaned engine and tranny tonight.

Now he's talkin about replacing the front and rear seals while we have it out.

Didn't this start as a simple carb fix lol He's got the fever bigtime :lol:

yea im gonna replace the front and rear seals since the engine is out. Also i have been really tied up with work and life in general. Got a baby boy coming in april. getting married next month.and looking at houses or land to buy. so really not having time for my project. I have had so many ideas since i have been working on the truck. Other than the motor, Any ideas on replacing the dash with something that has brighter lights in the dash. Just ideas popping up everywhere.

congratulations on your marrige and upcoming baby!!!!

as for your dash question. . . . .

i don't think you can make the stock gauge cluster any brighter, but you can replace your gauges with aftermarket (like autometer) ones that have better visibillity. if you wanted to go all-out you could make a custom dash for your new gauges or you can just coulmn-mount them. unfortunately, i don't know a cheap, junkyard-style upgrade for the gauges.

here is a pic of my 510's dash for inspirational porpouses. the only stock gauge i am still using is the fuel gauge.
http://files.automotiveforums.com/gallery/watermark.php?file=/503/385373afmy510b-med.JPG

ya prolly gonna go with a complete custom dash. mmmmmmmmmmmm I think i can do it lol

wow cool engine!!