New to me Nissan 720

[Williamdllr]

How's it going everyone. just dropping in to show ya'll my 1985 Nissan 720. i plan on doing a engine swap eventually, among completely restoring her to her former glory. i absolutely love this truck. no power steering, no power brakes, no A/C, no radio, runs rough when she gets warmed up but i believe that is due either to the carb or vacuum lines. i want to do the vacuum line elimination here in the next few days, im trying to make this truck as basic as possible. shes has some rust but nothing really really bad yet.

 

 

 

 

 

 

 

 

 

 

 

 

 

Yes you're reading that correct, 352,000 on the original motor. never been rebuilt or anything.

 

 

 

 

Random wires hanging from underneath the dash from the previous owner.

 

 

 

Could use new door panels eventually but these are serving a purpose for now.

 

 

 

messy messy messy z24. cant make out much of anything.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

[datzenmike]

You have power brakes, the booster is right there behind the master cylinder.

 

 

You can neaten it up by placing the spark plug wires back on the looms on the valve cover where they belong. Wipe them down with a rag soaked in WD-40 first to remove all that crap off of them and make them black again..

[Williamdllr]

I'm not much of a mechanic lol, The last owner said there was none but as you cant tell from the condition of everything, neither was he.

[JoeCool]

Good find! And that mileage is inspirational. With only 147,000 on mine I can drive it another 35 years! As for the rigged up crap, the previous owners of mine did a lot of that as well. Three years later I am still finding and fixing rigged up stupidity. Some things I can understand, but c'mon now, a damn battery hold down is only a couple of bucks! A bungee cord... REALLY?!

[olderdat620]

Don't know the state smog laws of Florida but if it passed smog and you said youd eventualy do a engine swap how bout justa L20 plenty of power simple and clean :confused:

[Williamdllr]

took off the intake and found that this flap is stuck open. seems as if the spring is completely worn out and useless. i started the truck up and gave it some gas and the flap doesnt move at all. im not sure if that is supposed to happen or not. nor do i know if its one of the reasons my truck runs rough when warmed up

 

 

 

 

 

[Williamdllr]

and yeah there was quite a few homemade solutions in this truck lol.some understandable and others downright bewildering.

[Williamdllr]

Don't know the state smog laws of Florida but if it passed smog and you said youd eventualy do a engine swap how bout justa L20 plenty of power simple and clean :confused:

i was thinking about that. I definitely want to keep a nissan motor in it, so no 350's or anything. im not too worried about gas mileage once i do the engine swap, its gonna be a nice track toy and weekend fun car

[wayno]

That flap is the choke, it should be wide open except when starting it the first time everyday day, but it might not even be hooked up, are there any wires connected to the black cap behind where your finger was when you were holding it closed?

There are a lot of wires and vacuum lines that need to be connected and working properly, if they are not doing what they are supposed to be doing(disconnected), then your likely lucky it even runs at all, there are some engines that deleting things don't effect it that much, I don't believe the Z24 is one of them, if you don't know what a wire/vacuum line does, then leave it alone, as you might need it, and if you delete more than one wire/vacuum line at once, which one that you deleted is the one that you needed to make it run?

These engines have a lot of wires/vacuum lines that do things as it has an electric brain of sorts, so if you take a wire off that the ECU needs to make decisions on how to control the engine, the engine might run like crap, it may idle badly, it may not even run because the wire deleted may be the one that supplies the fuel when the truck is right side up, and yes I believe that truck has a wire that tells the fuel pump when the truck is upside down and to stop pumping fuel, what if that wire is needed to tell the brain the truck is on its wheels.

I would put everything back to stock and just drive it.

[Williamdllr]

I figured it was the choke but wasn't %100. It just stays open no matter what though. And I want to leave it as stock as possible until I do the engine swap and what not but I need it to run right when it warms up. It almost wants to stall out anytime I push the clutch in or come to a stop. It runs beautiful when it's cold but once the engine heats up it starts going downhill :/

[wayno]

The choke is electric, so you need to find out if the wires are connected to it, there likely are a lot of wires going to the carb, they all need to be connected to the wiring harness.

Vacuum lines are also important, if someone started deleting them, then you likely will have to figure out how to put it back to stock configuration.

[datzenmike]

Don't know the state smog laws of Florida but if it passed smog and you said youd eventualy do a engine swap how bout justa L20 plenty of power simple and clean :confused:

 

The L20B will never pull the heavier 720 around. That was true in '81 when they switched.

 

 

 

The carb that you have is an electronic feedback carb. It's sort of like between a carb and fuel injection. The main jet is a solenoid that varies the jet size during running. An O₂ sensor provides feedback to the ECU that keeps it around stoichiometric for best economy and most of all emissions. The ECU has and needs lots of inputs to figure out the mixtures. If there is a failure in the system there is a 'limp home' fallback mode to prevent an over lean condition. Naturally it runs rich and poorly..

[Williamdllr]

Most of the vac lines are dry-rotted to hell and back. I'll probably go to the auto parts store tomorrow and buy enough to replace all of them in one go. I will also take a look at the back of the carb and see if any wires are disconnected/broken. Money is a tad right at the moment so I'm trying to do a budget job right now if that makes sense. Buy only what I need and work on the rest myself to save money

[datzenmike]

Take note some of the hoses may have small restrictions in them to delay action of the vacuum signals.

[VFR800]

A real "fixer upper" :)  

[that-son]

one of the first things i did on mine was clean/check all (or most) fuses and electrical connections.  i used a can of deoxit gold and just sprayed it on as many contacts in the cabin and engine bay.  if you're not deleting the vac lines and smog components then you've got to hook up all lines and check all the smog stuff.   try  some carb or even brake cleaner on all carb linkages before you lube them.  make sure you clean out all the build up before you lube. 

[crimsoneclipse]

No emissions in Florida that i know of. 

 

The choke really isn't necessary in Florida either. (maybe cold 2 days a year)

 

If you're staying within the state lines, you can also put in a webber carb, set the mixture and forget it. (no mountains to worry about leaning in)

[Williamdllr]

A weber is definitely in the future. Went and picked up a variety of vac caps so I'll eliminate one by one to make sure she still runs ok without them, besides there are no emission tests in fl so no real need for them (besides one?) if I understand correctly. I just want to it to rely on fuel, air, and spark to keep things simple until I start putting my dream into reality.

[newdatsunowner720]

What all lines would be capped off ? Anybody have a pic of this?

[datzenmike]

Engine will run best and give best mileage with all vacuum lines and equipment functioning properly. There is no magic power gains from pulling things off and a good chance that it will run worse if you do. At full throttle and idle the Z24's emissions system is non operating and has zero effect. At part throttle it runs cleaner but best of all gives better mileage.

 

You can swap a 32/36 or a 38/38 weber on for more power/torque but get one with an electric choke and idle cut solenoid that will allow it to match the stock electrical system. You can even modify the stock air cleaner to fit the weber. This will make warm up easier and faster and improve what I call drive ability in all weather conditions. It also has a larger and cheaper air filter than the weber.

[720inOlyWa]

Great idea, Datsunmike! A stock air cleaner on my weber- I am a doin it! Thanks!