New-to-me 720

[CharlieW]

Guys....I am a little puzzled....ok so I started the lowering process Monday night. I will put up pictures tonight, but I did the passenger side Monday night.....only two jacks and no jackstands so yeah...all I can do is one side at a time...lol. My kids get in the way of me finishing both sides Monday night, so I decide to do the drivers side last night. It seems as though the driver side is a little higher than the passenger side. I used 2" blocks on both sides and the suspension looks almost identical on both sides, but when you look at the truck from the rear....it just looks funny. I will be driving it to work tomorrow, so I will get a better idea of what it looks like on a flat surface because my driveway is a little sloped on one side. Its funny because the driveway is sloped very little, but enough so that the way the truck is parked it should be lower on the driver side, but it looks perfectly level from the rear. Oh well....any ideas would be awesome, but I will park it on flat ground tomorrow and see what it looks like.

[CharlieW]

So, we got the truck on the alignment rack a little earlier and dropped the front about 3" via torsion bars. The right rear has a saggy spring thus it is about half an inch lower than the driver side. Does anyone around have a set of leafs layin around they don't need anymore? By the way, I will put up pics tonight.

[CharlieW]

Alright....so next, I let the truck warm up a little this morning and when I get in it to tap the throttle and turn off the choke, it won't idle. I am gonna try to turn the idle screw a little bit, but it just won't idle. It did fine last night, but this morning it doesn't.....sucks. Any ideas are greatly appreciated. I know what ya'll are gonna say.....'get a weber'...but I don't have that kinda cash. It was hard enough on the wallet with what I have already had to do to get it mobile. If any of ya'll have kids and mortgage with a wife out of work, you know what I mean. Its tough. If you guys know anyone that has a weber they wanna donate, let me know, but for now, any pointers on the s*** would be great!

[noface]

I think you'll find that the more you drive it, the more you're going to find out how far the carb is out of tune.

It's very difficult to say...

make sure all the mechanicals are in working order, choke pull off, levers, springs external stuff.

Look down the throat, and set the butterflies to where they're closed (by adjusting the idle screw -linkage). You might want it open just a crack, but not much. The idea is you want it to idle on the idle circuit, and not the slow speed jet. If the butterflies are open too far, adjusting the idle mix screw gets you almost nowhere... You can do this by backing off the idle speed screw until it no longer influences the butterflies, then adjust it back in until it just touches or nudges the butterflies...

With this done, fire it up and get it running. You may need some help from a friend to kind of pat the throttle to keep it running. Then start adjusting the idle mix screw and get it to idle there. Adjust for lean best idle, that is, the best idle you can get without going to far. A general rule of thumb is that if you're more than 3 turns out on the mix screw, somethin else is mucked up...

Once you get best idle on the mix screw, then set the idle speed screw (linkage) to get the rpms you want.

A vacuum gauge really helps when doing this. If you have one, always adjust for best/most vacuum.

HTH,
JS

[CharlieW]

[breadbox]

It'd look great 2" lower.

[CharlieW]

...so the carb is.....in a half million pieces....and totally cleaned now...Should be reinstalling tonight....will let yall know how it drives afterward....I guess I should fill you in on the latest...the day I posted that I drove the truck to work, it sputtered a lot, but idled great. The following day, it wouldn't idle worth a crap but didn't sputter at all under a load....totally weird. So that is what drove me to remove and rebuild the carb, which is almost done. I have a detailed write up of the carb removal with pics that I will post in another thread. I have yet to make a rebuild thread. I will next time. I was trying so hard to concentrate on all of the little pieces and I didn't want to make any mistakes. I may be able to write a how-to on the rebuild from memory. Not sure yet.

[CharlieW]

...ok so I reinstalled the carb last night....very simple....especially with the vacuum line delete. The mixture screw is 2.5 turns out, and I adjusted the idle screw to get the idle down. When I was buttoning everything up before the initial start, I looked over towards the distributor and noticed that the wire to the vacuum advance was pulled off of the terminal. It looks as if the wire had gotten caught by the joint/knuckle down between the steering shaft and the steering gearbox. Also down there was the harness that housed the three wires from the ignition coil area down to the distributor, although those wires were not disconnected. So, I fixed those and then noticed that the hose....that I just replaced...from the vacuum advance over to the little metal tube that runs across the front of the engine to the carb....that hose was torn almost in-half right where it meets the end of that metal tube. That is very interesting to me as I can't figure out how it happened. Oh well, after those repairs and re-routing a couple other wires, I fired it up. The idle was extremely high, so I turned the idle screw down a bit. This seemed to fix that problem although I have found that the idle screw is EXTREMELY sensitive. I drove it around the block a bit last night and it ran great....it just hesitates....VERY slightly when you mat the accelerator pedal....then picks up just fine. After it got to operating temperature, I shut it off and restarted about 5 minutes later. The idle seemed to come down quite nicely.
So on to this morning, I go outside to start the truck and as soon as I hit the ignition, the truck started immediately...yay...but it idled extremely high again. As soon as the choke cut off, the idle came down a little, then it came down again to where I adjusted it last night, once it was at operating temperature. Any ideas why it would idle abnormally high on a cold startup? Lemme know what you think. Otherwise, it ran great over my 8 mile journey to work. No hesitations, sputters, or anything like that....oh and I sincerely appreciate all the help that has gotten me this far.....Thanks so much.

[noface]

there is a high idle adjustment screw that sets the idle speed while it's on full choke. Find it and adjust it to around 1500 - 1800 idle when choked.

It's likely to idle a little high (compared to normal) at around half choke, so no worries there really.

The idle mix screw being "sensitive" is a good thing. Use the procedure I posted above to get your lean best idle, and it'll run better... back off the idle speed screw to close the butterfiles as much as possible, fully closed is preferable, then set the idle mix screw to get max rpm, smoothness, or vacuum. Turn it only 1/4 turn at a time, let it settle, etc, till you get the best idle you can.... after your happy with that, then set your idle speed rpm to what you want.

Note that the tach is probably a little "happy"... mine is... it shows about 1000 rpms when it's really about 850. I set mine with an inductance tach/tester (well, actually now I set it with a laptop, but you get the idea....)

Good Job!

Not many men can take one of these critters apart and get it all back together with no pieces left over! LOL!

[CharlieW]

Wow...its been a long time since I posted here, but I want to let u guys know that without all ur help....this little beast would still be parked in the driveway lol. Man this truck runs great...but I must be new to Nissan because the engine makes a ton of racket to only have 58000 original miles...at any rate, she is my old school mini truck, so in old school mini truck fashion...check the steering wheel. Oh, and I got that carb back together and tuned with no spare parts...although the choke idle setting adjustment made me think about having a few...lol. THERE is much more to comeß

[noface]

wow... I don't know if that's cool or not... I know I wouldn't like it driving it around town. Would be cool if your truck was like a F1 car thats only a half turn either way to get to the steering stops, but on a real world vehicle, I'd consider that unsafe... but to each their own.

Good job with the carb.

[CharlieW]

Its really fun to drive around town....bit as bad as one might think.....you get a ton of leverage when you place your palm on the bottom of the wheel where it is cut to push up on....It works extremely well. I didn't think I would like it, but after all, what fun is it if we are like everyone else...lol....

By the way..does anyone have any decent looking 6-lug wheels they wanna donate...lol

[Steveka24det]

as for the 6 lug wheels look into a set of 15inch chevy rims off a z71 pickup somewhere in the mid 90s you might be surprised what you can pick up at your local junkyard

[bracktheron720]

im gunna pull my carb off rite now and get it ready to rebuild in the next couple days...any sugestions???i know my way around cycle carb no problem but this is a first for me!!I wont pay sumbody to do sumthing that i can do myself and learn alot so i decided to just do it and stop puttin it if..any help would be great !! thank sin advance!

[CharlieW]

For sure...couple of quick questions first...does your pickup still have A/C? If not, you can take the plunger out of the idle up solenoid and screw it back in....it raises the idle when you kick on the A/C....kinda self explanatory...lol. If not, then if you kick on the A/C switch on the dash by accident, there would be no load on the engine if the compressor was removed, but the carb would still idle up. It is the only electrical solenoid on the carb. Best I remember it has a single white wire going to it. My truck already had the A/C partially deleted and someone had already taken out the plunger. On the rebuild, the float level is extremely critical on these little hitachis. Your kit should come with the little measuring tool and instructions. The hygrade kit part number is 1514. These are good quality gaskets and rubbers, although it doesn't come with a new filter for the carb inlet. This carb kit also has gaskets for this carb on other applications, so there are multiple gaskets that are almost identical. MAKE SURE YOU PICK OUT THE RIGHT ONES FOR YOUR APPLICATION. (CAPS=IMPORTANT...lol) The differences are extremely small and if you were to install the wrong ones, you might play hell figuring out what you did wrong because odds are the truck will run like GARBAGE because the different holes either flow or restrict fuel to various locations. The carb will come apart in 3 sections. I recommend taking out one jet at a time from each section...cleaning it and its flow passage....and reinstalling....then move on to the next one. Reason being, there are a couple that have detent balls underneath them that will fall out. Do this job on a neat bed of red rags so that you can see if those balls fall out. When you are replacing the accelerator pump which will come new in the kit, it has two adjustment holes at the top where the linkage hooks up to it on the outside of the carb. On mine, the linkage hooked into the top hole and it works perfectly. The linkages on the side are a little bugger....I took a bunch of pictures of how it goes together before I disassembled...that helped beyond belief. Thats the only advice I can give you on those linkages. I think you will find that when you reassemble, you will be able to see just how much it has been adjusted over the years to accomodate for trash and such. I totally started fresh. There is a good little tutorial above in this same thread that I used to adjust mine out. After setting the idle, you need to set the high idle/choke idle which is not in that post. That is one...pain in the neck. All I can say about that one is good luck. You gotta have a special tool....This adjustment sets the idle rpm when the choke is on when you first cold start....mine was extremely high....like almost 4000-5000rpm. So not good for an engine. That definitely needs to be set and then follow the post above. At first, my mixture screw was 2.5 turns out, but I found that it spark knocked after it got hot, so I went out another 1/4 turn. It helped a lot but did not get rid of all of it, so I think a timing adjustment will be next.
Next question is have you done the vacuum line delete yet? If so, the just make sure that ALL of your vacuum nipples are capped off. If not, they will cause a ridiculous vacuum leak and you will never be able to get the carb set right, because you will always be having to compensate for a ton more airflow than it was designed for. With that being said, if you haven't done the vacuum line delete yet, now would be a great time to do that. The only vacuum line you need is the one from the base of the carb to the vacuum advance on the side of the distributor. All of the other garbage can be deleted. I heard a lot of people say a lot about their fuel mileage going to crap after the mod, but I haven't seen a difference at all. It runs a lot more smooth as a result too. This would also be a good time to start replacing fuel line. With the carb and vacuum stuff out of the way, the two problem lines just below the intake are easy to get to for replacement. You will also find a intake heater directly underneath the carb. It is a little phenolic piece in between the carb and the intake manifold. I am not exactly sure what it is for, but I do know that the venturis in these carbs get extremely cold...like cold enough to sweat on the outside of the carb body in SC humidity....with that in mind, I just decided to clean mine out and put it back on. One side is open and the other side has the honeycomb heater, so it is not gonna slow down airflow that much. If you get into it and have any other questions, feel free to email me @ [email protected], and I will try to dig up my memory.

[bracktheron720]

Wow thanks man!! first two things...No a/c....and no vac lines left on my truck....i got the carb pulled last nite wasnt to bad with all the vac stuff gone..got it in the shop and started takin a ton of pictures...and pullin it apart..i dont think im gunna have a problem gettin that all back together..i hope...lol where did you purchase your kit from??i wanna make sure i get the rite one so if yours worked out ok im just gunna try to order it where ever you did...im not sure about the spacer your talking about when i pulled mine last nite there were the four nuts holding it on pulled it off and im lookin strait into the intake no spacers or nuthin...but anyways iv got it torn down and ready to b put back together...ill be ordering the kit in the next day or two..So im sure youll get an email from me pretty soon with sum more questions!! this is kinda random but any idea why my intake looks brand new and everything else under the hood is coverd in a 30 year old layer of gunk???? even the carb is all gunked up but the intake looks brand new..lol i just thought it was kinda funny......

[CharlieW]

Not exactly sure on why the intake would look brand new....I will say that mine was extremely nasty....on another point, I work in parts at a Chrysler dealer and my mechanincs are horrible about not cleaning or touching anything that doesn't need it even if it is part of what they are working on. So if that truck needed an intake and it was replaced at a mechanic shop, odds are they wouldn't have cleaned anything else when they dropped it on. I see it all the time and I have worked with mechanic shops for over 15 years. Now as for myself on the other hand...when I pulled my carb off I cleaned EVERYTHING...lol. I will try to dig up some pics of the heater spacer.....someone may have already taken yours out. What is the climate like where you live? I was advised to leave it in just because these carbs venturis get so cold....and then after install, I witnessed this. After 3 hours of steady driving because I was so excited about having it running....I pulled into my driveway and popped the hood...Roughly 98 degrees out and sunny...engine bay hot enough to melt your popsicle....and the middle of the carb felt ice cold and it was sweating on the outside of the carb body. A local import racer and mechanic....has worked on Nissan's for 35 years(self claimed)....told me that even though you get a lot of hot air to these engines, they need warmer air because the carb cools it down so much. He said that was the reason for the pre-heater tube to the aircleaner snorkel and the two exhaust pipe tubes from the exhaust manifolds to the front of the air cleaner housing...as well as the heater base plate between the carb and intake. So my truck runs good and has good power with them still intact so I am leaving them there....a lot cleaner than before lol

[CharlieW]

[bracktheron720]

oh wow what a trip i got nuthin like that!!lol i live in the desert.....we get rain a couple days a year if were lucky.....if i drive over the pass to the west side of washington its a different story..very wet.....but on my side its hot and dry....all the other tubes and what not are still there just not the heater..thanks for all the help !!!oh yeah do you remember were you got your carb kit from?

[CharlieW]

I got mine from a mom and pop type parts store here called Midway auto parts. If you wanna send some cash my way, I would be happy to get you one ordered up and ship it out to you, but it may be easier for you just to search the info on the good ole www and buy it online. It is a Hygrade kit part number 1514. There is also a handwritten number on the box that is CPA406. See what you can come up with. Either way, if I can help lemme know.