# Has Anyone Swapped their Hitachi for a weber/holley/Z24 Carb? Please Help!



## BII (May 13, 2004)

Ok, so my carburator is finally giving up (well, its more like I'm giving up putting up with its shananagins). Well, I think I have the hopeless chokeless I hear so much about since I have a computer under the passenger seat. Anyways, I want to swap it put I can't see where to start.

--Do I plug all the vacuum lines that go to it when I install the new carb? 
--What other parts do I need to change/modify (e.g., distributor perhaps)?
--What about the computer? Do I unplug it/ignore it?
--Are there pitfalls/tips I should know of?

I don't care about smog or anything, I just want the damn thing to run right!


Many Thanks.


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## BII (May 13, 2004)

Ok, well does anyone know if I need to modify the ignition? I guess I'll fugure the rest out myself.


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## blownb310 (Jun 10, 2002)

bII said:


> Ok, well does anyone know if I need to modify the ignition? I guess I'll fugure the rest out myself.


It's been covered in the E/CA section here: http://www.nissanforums.com/showthread.php?t=7977

Here's the clip you're looking for:

Next, you might want to get rid of the troublesome "hopeless chokeless" electronic feedback carburetor, and replace it with a weber 32/36 progressive downdraft replacement, which uses an adapter, to mount. I replaced the stock cam with a Nissan Motorsport # 13020-25M00 "Euro" cam. It is a nice street cam that is O.E. in the European [non-emission] market. And if your crank angle sensor, [a.k.a. distributor] craps out, you can use the regular electronic ignition distributor assy. from an '82 or '83 B11/N12, and ditch the ECU completely. Then you can set the timing where you want it, and not have the ECU constantly changing the timing on you.


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## blownb310 (Jun 10, 2002)

More for you here: http://www.nissanforums.com/showthread.php?p=123167#post123167

I reposted all of the pics as digitalpose is no longer active. I used the Z24 carb because I had one. If you didn't have access to one, I'd just get the Weber conversion with the 32/36 carb and that would work great too. Someone mentioned a problem with the Weber adapter not covering the coolant heating passage in the chokeless E16 intake. I never had that problem because I used the earlier '82 and '83 choke carbed E16 intakes.


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## BII (May 13, 2004)

Ok, I found those posts but here's the thing:

I'm reading the haynes and it has the vacuum line diagrams (I *think* I can figure out how to install my newly acquired 32/26 weber). But if I install the weber, and in essence, cancel the vacuum/electronic feedback how is that going to affect the ignition system? Blown310's post alludes to using an older distributor to ditch the computer but how is this done? Also, do I need to change the coil or should I use the same one? Mine is that little black one that has something else connected to it.

I also remember in my quest (searches) someone saying that you can either run a hose or something to block the coolant thing on the intake manifold, I guess that's used to provide feedback to the computer, which if elimanted I guess is no big deal.


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## blownb310 (Jun 10, 2002)

I see that your car is an '87 sport coupe. If that's the case, it should have the E16i with electro-injection. Are you sure you have a chokeless carburetor?


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## BII (May 13, 2004)

Its not the sports coupe, its just the regular 2-door coupe.


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## blownb310 (Jun 10, 2002)

bII said:


> Its not the sports coupe, its just the regular 2-door coupe.


Oh OK, as far as I know anything other than a sport coupe is considered either a 2 or 4 door sedan. In any case, to try to answer your questions, after the Weber carb is installed the rest of the vacuum hoses can all be thrown away as far as I am concered. Will the stock ECCS ignition system still function properly?, I don't know. I never tried it. I always swapped in an '82-'83 regular electronic ignition dist. from an E16 powered B11 or N12. In that case, yes, you'll need the correct round style cylindrical coil that matches the dist. Whatever car you get the dist from, get the coil too, and take note of the wiring. It is pretty simple, like two wires I think. As far as what to do to block off the coolant ports at the carb gasket flange, I have never had to do that. Again, the same car I got the dist and coil from, is the same car I got the intake manifold from, and the '82-'83's don't have water passeges in the intake. But, I did see a reply by someone saying that they simply used pipe plugs to block off the water, no problem.


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## BII (May 13, 2004)

Yeah, sorry about the confusion. It it is a 2-Door Sedan.

Isn't the old-style distributor a vacuum-advance type? If so, how would I connect the vacuum-advance when I install it on my car? I guess if the vacuum line (if there's one) on the distributor comes off the intake manifold then I should definitely use the old intake manifold. Hopefully I can find the distributor and manifold at a junkyard this weekend.


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## blownb310 (Jun 10, 2002)

bII said:


> Yeah, sorry about the confusion. It it is a 2-Door Sedan.
> 
> Isn't the old-style distributor a vacuum-advance type? If so, how would I connect the vacuum-advance when I install it on my car? I guess if the vacuum line (if there's one) on the distributor comes off the intake manifold then I should definitely use the old intake manifold. Hopefully I can find the distributor and manifold at a junkyard this weekend.


Yes, the old dist. is a vacuum advance type. I don't know if a Weber has any vacuum ports on it, but normally you would hook the vacuum advance up to a ported vacuum carb fitting. In other words, one that does not have vacuum on it at idle, but kicks in during part throttle. Hatachi carbs always have a ported vacuum fitting on them, so you wouldn't be tapping into a manifold fitting that is at full vacuum.


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## BII (May 13, 2004)

Seems like there is a ported vacuum for the distributor Now if I connect the distributor and weber, should I disconnect the computer, or leave it be? Also would an aftermarket coil work in this setup? They're relatively inexpensive (and a good excuse to put a sticker on my car).


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## blownb310 (Jun 10, 2002)

bII said:


> Seems like there is a ported vacuum for the distributor Now if I connect the distributor and weber, should I disconnect the computer, or leave it be? Also would an aftermarket coil work in this setup? They're relatively inexpensive (and a good excuse to put a sticker on my car).











Yup, the yellow arrow appears to be pointing to a ported vacuum source, because the source is above the throttle plates. The purple one is an idle mixture screw and the green one is some sort of choke pull-off adjustment [or choke related at least]. 

I can't think of a reason to keep the computer connected, or even in the car for that matter. You've just covered all of the bases with the Weber carb and early distributor. Sure an aftermarket coil will work. Just get one that is intended to be used with electronic ignition [not points].


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## BII (May 13, 2004)

Blownb310 you are a lifesaver. Mad props to you, I don't anything about carbs, I guess I got lazy with the advent of FI. Of course tuning is going to be crazy, the carb I bought came of a 1.8L Porsche, so I might be close, in any case I'm getting jets with it so we'll see.


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## turbob12 (Feb 29, 2004)

I did the holley/weber swap on my 87 Sentra.I ended up with only two vac. hoses,pcv and brake booster.All wiring that went to the carb. was taped up out of the way,until I remove it along with ecu ,etc. later on when I switch the ignition system.Make sure none of the wires are bare and not touching each other or ground.I left all other wiring alone and it runs good with the stock ignition the way it came from the factory.No electrical modifications needed.My car doesn't have a choke either and I get by no problem but it doesn't get to cold in the L.A. area,I just pump the pedal once it starts first crank and within seconds i'm off running late to work again,no time for a long warm up,shouldn't have stayed up so late on this forum haha! Oh,yeah about the 2 coolant passages you'll find when you take the carb. off,if your adapter doesn't seal them just plug them,I was in a hurry and didn't have any pipe plugs so just got out my taps and found one that would thread the holes then put screws in and cut them flush with the intake,I used JB weld on the threads,they're never coming out or leaking!


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## blownb310 (Jun 10, 2002)

Thanks for the input as far as the ignition system goes. It's good to know that the crank angle sensor ignition still works without using the electronic feedback carb.


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## B11sleeper (Oct 15, 2003)

turbob12 said:


> I did the holley/weber swap on my 87 Sentra.I ended up with only two vac. hoses,pcv and brake booster.All wiring that went to the carb. was taped up out of the way,until I remove it along with ecu ,etc. later on when I switch the ignition system.Make sure none of the wires are bare and not touching each other or ground.I left all other wiring alone and it runs good with the stock ignition the way it came from the factory.No electrical modifications needed.My car doesn't have a choke either and I get by no problem but it doesn't get to cold in the L.A. area,I just pump the pedal once it starts first crank and within seconds i'm off running late to work again,no time for a long warm up,shouldn't have stayed up so late on this forum haha! Oh,yeah about the 2 coolant passages you'll find when you take the carb. off,if your adapter doesn't seal them just plug them,I was in a hurry and didn't have any pipe plugs so just got out my taps and found one that would thread the holes then put screws in and cut them flush with the intake,I used JB weld on the threads,they're never coming out or leaking!



hmm i might have some ?'s for you, i have a webber 32/34 or whatever that thing is, and i haven't yet put it on, I'm in Los angeles too.


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## BII (May 13, 2004)

Sounds like there's a grip of us in SoCali.


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## B11sleeper (Oct 15, 2003)

Ya there's Nismo87R - Danny and me there may be some others too


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## BII (May 13, 2004)

We should start a _Sentra Enthusiast Association of Southern California_.
SEAOSC


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## BII (May 13, 2004)

So, has anyone connect an electric choke? Any suggestions as to what wire to tap into?


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## B11sleeper (Oct 15, 2003)

the electric choke would need to be hooked into the circuit that is controlled by the coolant temperature thermo-switch so that the choke is on while the coolant is cold and then shuts off when the coolant gets up to temp.

BTW.. My 32/34 has a water activated choke, which seems like the more common setup... you could switch yours to water choke.

I guess i'm putting mine on my datsun 210 now, since i have that e15t for the sentra.


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## B11sleeper (Oct 15, 2003)

I got the weber working on the datsun.

basically plug every vacuum line except 1 from the manifold for the vacuum advance.

when done right the car will run. ( may not stop if you don't have it adjusted right... )


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## Bjorge (Jun 4, 2006)

Hi, I have an 88 z24i wich i recently swapped a weber 32/36 to. I did the following that was mentioned above in this post, but are still having trouble getting the engine to run more that app. 30sec. I do have the ecu still wired up because when i disconnected it the fuel pump stopped. How can i wire directly to the fuel pump without going thru the ecu since i no longer have use for it?
Bjorge


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## blownb310 (Jun 10, 2002)

Bjorge said:


> Hi, I have an 88 z24i wich i recently swapped a weber 32/36 to. I did the following that was mentioned above in this post, but are still having trouble getting the engine to run more that app. 30sec. I do have the ecu still wired up because when i disconnected it the fuel pump stopped. How can i wire directly to the fuel pump without going thru the ecu since i no longer have use for it?


 Bjorge,

You can't use the original electric fuel pump from your electro injected Z24i. Fuel injection uses far too high a pressure for carburetor use. The excess pressure will blow right past the carburetor's needle and seat and flood the fuel bowl out. For the Weber carb you'll need to either convert to a low pressure electric pump for carburetors, or adapt a mechanical pump if the mounting for it is still there on the Z24i. I think it's there but it's blocked off.


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## Bjorge (Jun 4, 2006)

*Hi,*

I am using the electric fuel pump, but have made an T piece for the return fuel line so that the carb isn't getting too much fuel due to the pressure from the pump(kind of fuel pressure regulator). But anyway, what model/year can i get an ordinary fuel pump from that fits the z24i engine? One that is not the electric kind.


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## blownb310 (Jun 10, 2002)

Bjorge said:


> I am using the electric fuel pump, but have made an T piece for the return fuel line so that the carb isn't getting too much fuel due to the pressure from the pump(kind of fuel pressure regulator). But anyway, what model/year can i get an ordinary fuel pump from that fits the z24i engine? One that is not the electric kind.


 I don't think using the electro injection fuel pump is a good idea, but it might work if you use an aftermarket fuel pressure regulator [Holley makes a good one]. Usual working fuel pressure for a carbureted engine is about 4 to 6 psi. 

Now that I'm thinking about it, I don't know if there were ever any mechanical fuel pumps on US models. Even the mid 80's carbureted Z24S trucks had low pressure electric fuel pumps.


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## Bjorge (Jun 4, 2006)

Hi, I finally got the engine running today! After reading a post here in this forum i managed to sort out why the engine stopped after running fine for app. 30 seconds.
The fuel pump on this z24i engine does start and stops after starting it. Don't really know why, but i did an bypass wiring the fuel pump using a 10 amp fuse in the ignition on position and then the engine was running continously!!!


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## BigBlockSentra (Apr 26, 2006)

i posted a thread about a clogged fuel system tonight. this might be a good option for me to switch the carb. are these weber carbs cheaper? i like the sound of getting rid of the vacuum lines. i think my tank is rusty inside though maybe i can just add anothjer filter for now then there will be two. if do the swap i will look over this thread closely. i am not to far from albany eother if you know where to get parts i may drive.


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## BII (May 13, 2004)

Bjorge said:


> Hi, I finally got the engine running today! After reading a post here in this forum i managed to sort out why the engine stopped after running fine for app. 30 seconds.
> The fuel pump on this z24i engine does start and stops after starting it. Don't really know why, but i did an bypass wiring the fuel pump using a 10 amp fuse in the ignition on position and then the engine was running continously!!!



AS blown mention, a fuel pump designed for FI is not good for a carb. FI needs high pressure, carbs need low pressure. Even big aftermarket pumps designed for racing apps (with carbs) are low pressure (but high volume).

Mr. Gasket makes an aftermarket electric fuel pump that pumps at about 3 psi or something. costs less than 30 bucks, worth it to save the carb.


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## plouche (Apr 25, 2006)

Ok I got this out of a book "turbochargers byHugh Macinnes" and here it says that you vacuum advance should be attached to the intake manifold. Here it will sense pressure in the manifold. if you like i will scan it and post it up with diagrams and everything.

(btw if you vacuum advance is not connected how does you ignition retard or advance?)

hope this helped


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## Frankie Pintado (Oct 25, 2010)

There is a way to use an FI fuel pump, outlined here, along with other possibly helpful pointers
forums.********.com/z24i-efi-tbi-to-weber-carburetor-conversion-t435279.html

******** = "nico club" without the space

OK that link won't publish here (WTF?). Just Google "weber z24i". It's the first, second and third link listed.



> Hi, I finally got the engine running today! After reading a post here in this forum i managed to sort out why the engine stopped after running fine for app. 30 seconds.
> The fuel pump on this z24i engine does start and stops after starting it. Don't really know why, but i did an bypass wiring the fuel pump using a 10 amp fuse in the ignition on position and then the engine was running continously!!!


THIS IS A TERRIBLE IDEA, AND SHOULD BE ILLEGAL IF IT ISN'T ALREADY. WHAT YOU HAVE DONE IS BYPASSED THE SAFETY SHUTOFF FOR THE FUEL PUMP. IF YOU ARE IN AN ACCIDENT AND YOUR FUEL LINE IS DAMAGED, YOUR FUEL PUMP WILL CONTINUE TO EMPTY YOUR TANK ON THE STREET EVEN IF YOUR ENGINE HAS STOPPED RUNNING, EVEN IF YOU'RE UNCONSCIOUS, EVEN IF YOU HAVE WIRES SHORTED AND SPARKING ALL OVER YOUR WRECKED RIDE. GETTING THE PICTURE? 

At least use one of these: Ford Ranger/Bronco II Inertia Switch found in abundance at any junk yard.

The way the stock safety works is it senses ignition +, turns on for five seconds. Then it comes on and stays on when it gets a signal that the engine is running from the crankshaft position sensor. Sounds like you're not getting a crank signal. This is very important. Burning to death is a crappy way to die.


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## Frankie Pintado (Oct 25, 2010)

I can't link to another forum? Please tell me there is a way, before I say something smart about competition and get booted out of here.


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## markhu (Oct 25, 2010)

I'm beginning to think that Holley doesn't make a carb for the 1985 Nissan pickup. Peb Boys said they had one listed for $400, but I think that might have actually been the stock Hitachi "REBUILT BY" Holley. Anyone know any different? Basically my question lead up to this: Is there an aftermarket carb that is California emissions legal?


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## fairlanephantom (Feb 3, 2010)

markhu said:


> I'm beginning to think that Holley doesn't make a carb for the 1985 Nissan pickup. Peb Boys said they had one listed for $400, but I think that might have actually been the stock Hitachi "REBUILT BY" Holley. Anyone know any different? Basically my question lead up to this: Is there an aftermarket carb that is California emissions legal?


They're rebuilts by Holley. Was the same deal with their Sentra carburetors. They weren't very good, I went through a number of them until I ditched them when my emissions were up.


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