1985 nissan 720 rwd california daily.

[captain720]

There are 3 fusible links on the 720. One goes to the ignition switch then to the fuse box for things that are shut off with the key like wipers, heater, ignition. One to the fuse box for head lights. One to the fuse box for things not turned off like horn, brake lights, interior lamp.

Even if these are worn and not dead yet it can be good to replace as they like to cause trouble inconveniently.

[datzenmike]

Well you could, but if not crispy, melted or obviously in good shape it's not needed. These are special wires with a hypalon plastic covering that resists catching fire when they melt internally. They may even look good from the outside. Wiggle them and see if the inside wire is crunchy or melted.

[captain720]

Well you could, but if not crispy, melted or obviously in good shape it's not needed. These are special wires with a hypalon plastic covering that resists catching fire when they melt internally. They may even look good from the outside. Wiggle them and see if the inside wire is crunchy or melted.

Mine were just about to fall off and frayed, coating was mostly gone, and they looked horrible, but still functioned so I replaced them. Keep the original ones as long as you can though.

[Toxicrain]

Should I just replace them anyways with new links to remove the possibility of the wires being weak or frayed? and where would I get them other than off another 720 which pick n pull doesnt have one right now.. I'm not sure if they have part #'s i will check my manual when i get a chance and look into it more.

Also wondering if its worth it to get her to a shop and have someone else track down the issue since the main setback has been resolved and i can finish getting the final pieces to rebuild the front end

[datzenmike]

They are color coded as to the current they handle. The 720 uses a Green and 2 Black? or Black and 2 Green? I forget.

 

Green .... 40 amps

Black ..... 80 amps

 

The true beauty of a fusible link over an ordinary fuse is that they can sustain an overload far above their rating for several seconds without damage. They are intended to protect the wires going to the fuse box in the event of an accident. Everything after the fuse box has it's own fuse to protect it.

[Toxicrain]

 

2 green 1 black. I wiggled them and they felt like a normal wire. Put new fuses into the ignition and engine control fuse to cancel out that problem.

 

I will check it out on my next day off.

[datzenmike]

Put a volt meter on the far end and wiggle them. If the meter jumps around they may be broken internally.

 

 

 

Do you have a tach in the gauge cluster? or did you put a tach in the cluster?

[Charlie69]

Stock fuel piping and stock or facet fuel pump ib all I run with my Webers on my 720s.  Installed stock 720 fuel pump on my 66 520 L29B automatic.  I will aslo run the 720 fuel "Y" pipe and fuel return.

[Toxicrain]

Put a volt meter on the far end and wiggle them. If the meter jumps around they may be broken internally.

 

 

 

Do you have a tach in the gauge cluster? or did you put a tach in the cluster?

I will try to see if the links are bad but I think its just the post not making a solid connection it has happened before and I just re tightened down the cable to the post this is probably the reason too as why the alt isnt charging.. if I cant find a solution I might have to take a loss and have a shop look into it and hope its an easy fix.

 

Its the original 85" 720 dash cluster and when I bought it the rpm gauge never gave me any trouble until the bogging/stalling problem started to happen.. now it just gets worse and worse like a wire is corroded or not making a solid connection.. I tried to remove the cluster and didnt get anywhere because I am not sure how to properly do it So im going to look into that so I can try and fix it.. Even though the tach isnt that important because my truck is auto but its nice to have lol.

[datzenmike]

I've found that when the tach acts up it's only reading a faulty coil firing. Now this could be one of many causes, but if the plug misfires the tach will show a jittery reading. It's not always the gauge it's just doing what it's told.

[DIY 1985]

As an update on this and a couple of other threads, I got my EGR / BPT hooked up on my DGV, today. The vacuum line also is there for the charcoal canister as per FSM. So I'm running advanced static timing with centrifugal. The port on the DGEV now on my work bench, can pull the EGR plunger, but I had to disconnect the brand new BPT to make that happen. I didn't drive it though. Possibly both EGR and advance could be plumbed to the TVV (Borg Warner EC987) but I don't know if it will be good for a cold start. If I can buy a good VCV I will rebuild the Hitachi.

 

I'm pretty sure that the BPT does all the work and not the carb for regulating the EGR because the EGR plunger will bog the engine when the BPT is disconnected.

 

I had to drill a hole in the throttle plate (secondary) with a #60 drill .040" to complete my tune which included smaller main jets and bigger air correctors. Altitude.

 

The Z24-DGV-kit came with two F5 emulsion tubes, the engine-generic DGEV came with a F5 and a F6 in the primary. I don't know if it is relevant.

 

I ultimately chose the DGV because I don't feel like getting power off if the dead blue wire, or running a new relay. The conversion kit for manual choke is pretty crappy, and the DGEV has a stepped fast idle cam that requires you to operate the gas pedal.

 

There is something so cool about running a carb and having less suit in the tailpipe opening than a fuel injected vehicle. Plus, like Mike says, few thieves could figure it out.

[Toxicrain]

 

Anyone have a part # for the links? I have been looking at nissans diagrams and its not giving me a clear explanation.. I am going to just find new links and replace it hoping that it is the issue. if not ima try and find a shop that will look into my no charge issue... At least im 1 step closer to being able to daily her again.

[DIY 1985]

Never mind on that DGV port to EGR. It worked well only in neutral. Perhaps an office from the stock emissions lines. I have like 4 of them, they are different in size, where do they go on the original plate of spaghetti? It probably was working well last week with the routing on the DGEV, but I don't know how to tell.

[datzenmike]

 

 

As an update on this and a couple of other threads, I got my EGR / BPT hooked up on my DGV, today. The vacuum line also is there for the charcoal canister as per FSM. So I'm running advanced static timing with centrifugal. The port on the DGEV now on my work bench, can pull the EGR plunger, but I had to disconnect the brand new BPT to make that happen. I didn't drive it though. Possibly both EGR and advance could be plumbed to the TVV (Borg Warner EC987) but I don't know if it will be good for a cold start. If I can buy a good VCV I will rebuild the Hitachi.

 

I'm pretty sure that the BPT does all the work and not the carb for regulating the EGR because the EGR plunger will bog the engine when the BPT is disconnected.

 

I had to drill a hole in the throttle plate (secondary) with a #60 drill .040" to complete my tune which included smaller main jets and bigger air correctors. Altitude.

 

The Z24-DGV-kit came with two F5 emulsion tubes, the engine-generic DGEV came with a F5 and a F6 in the primary. I don't know if it is relevant.

 

I ultimately chose the DGV because I don't feel like getting power off if the dead blue wire, or running a new relay. The conversion kit for manual choke is pretty crappy, and the DGEV has a stepped fast idle cam that requires you to operate the gas pedal.

 

There is something so cool about running a carb and having less suit in the tailpipe opening than a fuel injected vehicle. Plus, like Mike says, few thieves could figure it out.

 

 You have a non stock carb on your engine so forget making the EGR work. Disconnect the line or lines going to the EGR and the BPT valve. The EGR then becomes inoperative and can't cause you any problems. Without a connection to a vacuum source from the carb the EGR stays closed and cannot cause a vacuum leak.

 

I don't know anywhere that suggests a hole be drilled in the throttle plate to 'tune' a carb.

[DIY 1985]

Drilling from Pierce on video. The idea was to not have to switch to a 38 synchronous. Many sources say that the 32/36 are too small for the motor, much less when you are two miles above sea level. The point of the drill is to not open up idle speed because the you have ported vacuum at idle and you are using the primary main jet. It works based on a/f readings.

 

The EGR is cool, because design in general is cool.

[DIY 1985]

A PCV valve would also be a vacuum leak, but it stays, for now.

[Charlie69]

85 720's are notorious for having intermittent fuel pump relays. If you are still using the stock wiring to power your new fuel pump, it could be the cause.

We were scotch locking the wiring at the relay to diagnose that in 1985!

My repeated experience has been faulty ignition switches not fuel pump relays.  And I never use scotch locks even in a temporary situation.

[Charlie69]

I have run Webers 32/36s for over 40 years and have not had a Weber 32/36 that was to small for any 4 cylinder Datsun engine.  I bought a 1986 720 king cab 2 wheel drive when I was in Carlin Nevada over 5 years ago and bought it cheap because it ran like shit.  I got it home and called Pierce Manifolds and ordered a new Weber DGEV 32/36 for it.  It took 5 days to get to me.  and in the mean time I raised the truck to stock height (it had been slammed).  Flushed the power steering and did an complete tune up.  Disconnected all vacuum lines except 1 from the carb to distributer then I put the 32/36 on and adjusted it.  It has run like a top eversince.  I say bull shit to the Weber 32/36 being to small for a stock Z24 or a KA.

 

You need to study more and get intimate with your Weber!

[Charlie69]

When you install the Weber you use only the blue wire from the 6 connector plug for the electric choke unless your Weber has a fuel cut solenoid..

 

The factory carb on the 85 Z24 trucks is an electronic feedback carb that feeds information to the ECM, when you remove the foctory carb you remove that feedback circuit,

 

I keep the egr and oxegem sensor intacked on my 86 so I can hook the EGR up when I need to go through emmissions, I connect the vacuum line in the parking lot of the emissions and disconnect it after I pass emmisions.  The main part that gets me through emmission is a good catalytic conveter.

 

The simpilar you keep your truck the easier it is to dignose when you need to.

[Charlie69]

 You have a non stock carb on your engine so forget making the EGR work. Disconnect the line or lines going to the EGR and the BPT valve. The EGR then becomes inoperative and can't cause you any problems. Without a connection to a vacuum source from the carb the EGR stays closed and cannot cause a vacuum leak.

 

I don't know anywhere that suggests a hole be drilled in the throttle plate to 'tune' a carb.

The drilling a hole that Pierce Manifolds talks about is for track (performnce use) and I would not do it for a daily driver.

 

The 32/36 is already in stock form a performance boost to a stock Z24 engine over the stock emmissions carb.

[Toxicrain]

My repeated experience has been faulty ignition switches not fuel pump relays.  And I never use scotch locks even in a temporary situation.

running power to fuel pump off the red wire on the 6 connecter plug thing and going to frame after. I dont think that plug shuts off power for any reason when the ignition is turned on so my issue isn't fuel cutting out or not being delivered at all.

 

Any ideas on how to fix the bogging when the secondary is opened under 4k which the timing advances at around 2800 ive noticed on my z24 at least..

[datzenmike]

The 38/38 is a small V8 or 6 cylinder carb. The stock Z24 carb is a bit small for the engine size so a 32/36 is a good direction to go.

 

 

 

 

Any ideas on how to fix the bogging when the secondary is opened under 4k which the timing advances at around 2800 ive noticed on my z24 at least..

 

First I would plug that hole and see if this fixes the problem.

[Toxicrain]

 

Checked all the wires with a continuity tester and wiggled them too and it was solid. I asked the shop i work next to and they said it could be a bad new alternator from autozone even though its been checked?? Idk what the next steps are to trying to figure it out.. if i get a chance i might just drive it to a shop and get some more eyes on it.

[DIY 1985]

There is more air, in your air, in your part of Arizona than any part of New Mexico.  Pierce said 2 liters is about its max for 32/36.  In my Z24 DGV kit instructions, it states:

 

"When purchased in a conversion kit form, the Redline K646-38 conversion kit, for this High Performance Z24 Nissan Engine using the Weber 38mm DGES carburetor will perform very well on a stock unmodified 4 cylinder engines.  This is not considered to be "over carbureted."  This Weber 38-DGES is very close to the same size as the Hitachi designated for use by Nissan as the original equipment carburetor.  The 38-DGES is the logical replacement for both the 4cyl and 6 cyl applications."

 

The venturi sizes of the Hitachi, for all Z24 1985 720 applications are, 25mm on the primary barrel and 35mm on the secondary.  They are 34/38mm carbs.  (FSM Service Data Specifications)  The venturi sizes of the 32/36mm Webers are 26mm on the primary and 27mm on the secondary.

[Charlie69]

Did not realise this Is a "High Performance Z24".

 

You should not even be fucking with downdraft you should be running twin sidedrafts tuned to your engine.  Quit wasting your time.