FSM Wiring Diagram inaccuracies?

[Bob_D]

Hey thanks guys! I didn't know about the supplemental manual, so that is a tremendous help to me. Tony, my 73 as I recieved it had been modded at some point in the past so I don't have an electric fuel pump, just the mechanical pump, and I have the earlier "dome top" carbs instead of the '73 "flat top" carbs (although I do have those in my spares box). After seeing all the tweaking and fiddling that supplemental manual has in regards to those "smog" carbs, I am very glad that they were replaced! If I ever decide to go with an electric pump I will definately go with the inertial switch.

 

djwarner: I took a good hard look by my horns, and noticed a "lump" near each one in the harness. After unwinding a bit of the tape I found the bullet connectors for the fog lights! Thanks for the tip, I wouldn't have thought to dig into a taped up harness if you hadn't mentioned it. Anyone know where they put the switch for the fog lights in the JDM and/or Euro models?

[helghast7]

As for assigning Meanings "M=Maximum, D=Drive" why isn't it enough that they are simply "M" and "D"? There may be a logic to what letters they chose, but there may not be. At that time, the Japanese had some very strange translation issues... it was all over the industry. The Fairlady 432R has the Chassis Code "PS30SB" whereas a run of the mill not-intended-for-straight-to-racing-duty 432 got Chassis Code "PS30"---what> "PS30 Special Bersion"---and I'm NOT kidding! So you MIGHT think you are assigning logical names, but usually somewhere somehow the kid withthe camera saying 'thankyouvery much, hairpie hairpie" came back to Nissan in the late 60's and since he spoke such "good" English he dictated the names of things  and someone just wrote down what he said.

 

We had a senior engineer at our Japan Distributor who did our screen translations. It wasn't until he  RETIRED  that they requested that some screen translation Kanas be changed to reflect what they actually meant. Our 'coastdown timer' had been translated to "Gone on Summer Vacation".... the first Field Engineer that got an ENRAGED customer calling wanting to know why his forging plant was down and his machine tripped to "Go on Summer Vacation in October" was NOT easily translated  on our NCR paperwork!.

 

When Training on these electrical circuits instructors  would say "The  M Contact Set to the Headlight for Passing" or whatever. They were called  out by letter or number and rarely anything more. We do similar in our training "Power to Energise CR1A initiating Switchgear comes in on A1 and through the coil, exiting A2 to Earth." That's technically not what it does, but it's  how people conceive it does so that's how it's explained. They could have "Special Bersion" all over that diagram!

 

Slightly off main topic but on the topic of translation issues. Even as late as the 90's and I'm sure to this day we have these goofy things brought to a large scale. For you car enthusiasts that might know a thing or two about the mazda rx7's the 93-02 FD chassis rx7 had its engine coded as 13B-REW. Reason being, it was the new twin turbo model of the 13B engine and they gave it letters to signify that. When asked later what the REW stood for, mazda later stated that it stood for "Rotary Engine Double turbo" but since Japanese didn't have an exact translation for double they used the letter "W" since it was close enough. lol

 

Just a little FF for ya haha!

 

Also nobody knows why its called an Rx7..not even mazda can give an official answer lol.

 

 

On another note, I remember when Ford used to put them on the rear shock tower of their cars too. So much fun trying to figure out why the customers car keeps shutting off on them when they drive only to discover that when you hit a big bump the broken shock would hit so hard it flicks the switch lol.

 

Ford also puts them in the trunks of some of there larger trucks If I remember correctly, such as a few years of the naviagator/excursions.

[Tony D]

Actually, if you remove the EGR and run the Flat Tops....you will be surprised.

Most conversions do this, and in accurately attribute any improvement solely to the Carbs. As someone who "believed" and had brand new Round Tops installed on an otherwise functioning 73 sans EGR I can tell you for a FACT installing the EGR crossover and re-enabling that RADICALLY altered the way the Round Tops ran!

 

The flat tops utilize separate idle and main circuits, allowing a proper "power cut" on the needle while still allowing a lean enough idle circuit to cover emissions compliance. The power jet in them is similar in function to a Holley...they fail,they go rich.

 

I've recovered enough high mileage all original 240 and 260Z's to know Laziness and simple misunderstanding of the real issues manifest in the situation led to their "bad" reputation more than actually being an actual bad carb.

 

It's not a "Computerised Quadrajet"!

Edited July 13, 2014 by Tony D

[Tony D]

"Also nobody knows why its called an Rx7..not even mazda can give an official answer lol."

 

Because Rx3 & 4 were already taken and Letter/Number Combos sold in the US since Fairlady vs Savannah flies in Japan, but only plays well to Demographics in West Hollywood, Key West, San Francisco, and Sagatuck...

 

RX7 vs 280Z, that sounds flannel-shirt Logger Fisticuffs tough!

[DuoWing]

Reading through this thread makes me think of an issue I encountered the other day. I was wiring up my autometer tach to my 280Z and I ran the white wires for the backlighting to the factory pin for the green/white and a separate ground. I put everything in and it doesn't work. I look at the FSM and the harness I had and the green/white wire was in a different location in real life vs. the diagram. So either someone had messed with it or it's some kind of discrepancy. As for the ranger pump shutoff switch it's funny that was mentioned because just the other day I got in my friend's Mazda Rang...B2300 and I managed to knock that switch while getting into the passenger side.

[helghast7]

"Also nobody knows why its called an Rx7..not even mazda can give an official answer lol."

 

Because Rx3 & 4 were already taken and Letter/Number Combos sold in the US since Fairlady vs Savannah flies in Japan, but only plays well to Demographics in West Hollywood, Key West, San Francisco, and Sagatuck...

 

RX7 vs 280Z, that sounds flannel-shirt Logger Fisticuffs tough!

 

 

Lol, true, though I meant literally why they chose the complete letter number combo. Doesn't stand for anything officially and despite sales of numbers and what not, there was never an RX5 & 6 unless they failed preproduction which mazda won't officially say either. So it just is what it is.

 

Rx-7 vs. 280z......Jokes aside, after living through the rotary with  my old FC and FD. I'd say Z. For so many reasons.

[Bob_D]

Hey Tony, I know we are drifting off the original posted topic here, but my 73 still has the egr hooked up, along with the smog pump. The dome tops are bolted onto the 73 intake, so the hot water under the carbs has been removed since these carbs don't have the provision for it in conjunction with the 73 manifolds. From what I think you have stated above, having the EGR with dome tops is a GOOD thing, but if I had the flat tops on it, then the EGR would be bad? I will say that the car does run very smoothly once warmed up, and pulls nicely, but then I don't have any other 240Z frame of reference to compare against, this being my first one.

 

Helghast7: Actually , there was a Mazda Rx-5. Except here in the US it was called the Cosmo. I *think* all their rotary cars started with an R designation. Perhaps X was for "eXperimental" and the number was for the series. Rotary eXperimantal series 7 = RX-7?

[Tony D]

Many of the issues surrounding the Flat Tops (other than the power valve going rich) were directly a result of the extra heat in the engine bay/manifold caused by overzealous EGR.
Any 1973 vehicle has a bad rep---I remember I was told "never buy the 73 Chevys unless all the pollution crap was pulled off"... It wasn't really ALL the  "pollution crap" just some of it which was poorly thought out.

The 260Z was SUPPOSED to be Fuel Injected!

I had a 73 with a complete 71 Manifold on it, Round Top SU's that were bought new from Nissan, run for six months then the car was stored due to suspension issues.

That setup, with a header using the Smog Pump ran GREAT. The Engine tested clean to 1983 Catalysed standards. Astoundingly clean! 1/10th the allowable emissions.

Now, at that time there was a visual. They failed me for no EGR. So I retrofit the crossover and linkages, put in the pipe. Oh lord help me! It ended up passing on the last adjustment but ran like crap and JUST scraped by with something like 1000PPM HC or something... this was some while ago, but adjusted to pass the test the car barely ran at all. 

 

Anecdotal to be sure....but it was amazing to me how much different the thing ran afterwards. Now, if someone put a BB in the actuator line and it's  all there and just looks nice... That is something totally different. Mine ran great without the EGR going into the manifold!

[helghast7]

 

Helghast7: Actually , there was a Mazda Rx-5. Except here in the US it was called the Cosmo. I *think* all their rotary cars started with an R designation. Perhaps X was for "eXperimental" and the number was for the series. Rotary eXperimantal series 7 = RX-7?

 

Sort of but not quite, Eunos Cosmo was called the Rx5 in Europe so I suppose that does count but not all rotary powered cars had the designation RX in them, such as mazda's B2000 pickup. That being said there have been years and years of debate over at that god forsaken forum on the meaning of the letters but its all the same as this threads questions.