WTB. - 1986 Holden Piazza WATER PUMP & VACUUM ADVANCE UN

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sbs
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WTB. - 1986 Holden Piazza WATER PUMP & VACUUM ADVANCE UN

Post by sbs » Fri Dec 24, 2010 8:04 am

Hi there Folks,

I am redoing the head on my '86 Holden Piazza and while things are getting done I urgently need a near new or reconditioned Water Pump and a good working Vacuum Advance Unit for the distributor.
Does anyone know if the diaphragm alone is available for the vac. adv. unit?
Is the American 1986 Isuzu Impulse 2.0 litre turbocharged water pump interchangable with our Holden one?
Thanks as always for help in keeping our cars running. sbs.

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Post by wedgenut » Thu Dec 30, 2010 8:50 pm

Watch what you get from the US, they had g200z engine non turbo cars (1.9 litre) same as we did in NZ. The two engines use different pumps. Your engines were the 4zc1 as are all the 2.0 litre turbos, the 4zd1 (2.3L) certainly has the same pump and i think the 4ze1 (2.6L)as well but don't quote me on that.
I have a good used pump and may have a new one as well, need to check. I don't know if our Vac units are the same as yours though as you may have a different dizzy. Put up some piccies and I will check
So many cars, so little cash

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Post by sbs » Sat Jan 01, 2011 2:00 am

Hi there Wedgie,
Thanks for the advice on the pump. What are you after for your spare one incase I cannot find another? I will see about running off a couple of photos, or a part number or something, off of the dizzie tomorrow and get back to you. Cheers mate, sbs.

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Post by wedgenut » Sat Jan 01, 2011 9:51 am

New Pump complete with gasket (not an overhauled one) $120 AUD INCLUDING postage airmail to Australia (3-10 days) Isuzu part number 8-94131-330-2

I have two used pumps, one is known to be in good order and one is unknown but no sign of leakage and bearings feel good.

Good used $70 AUD delivered as above

Unknown used $50 AUD delivered
So many cars, so little cash

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Post by IZU069 » Sun Jan 02, 2011 8:23 pm

My neighbour has my vac advance (in his Toyota!). I'm waiting to get to a wreckers to get the proper one (instead of $70 or $170 whatever for a new one - that's called "get a Jaycar electronic timing kit instead"!).

Keep the Jaycar kit in mind = ~$99 for 11-step progammable vac & speed advance, though it requires a hand programmer (~$65?).
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Vacuum advance unit

Post by sbs » Mon Jan 03, 2011 2:25 am

Hey there Izu,

I am hopeful that I might be able to get a vacuum advance unit but, just in case the lead is a dud, would you have any idea of the Isuzu part number for the appropriate unit? Failing that I might have a look into the electronic ignition.
Thanks, sbs.

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Post by wedgenut » Mon Jan 03, 2011 7:20 am

Vac advance part numbers are:

March 1985 - August 1985 = 8-94248-519-0
September 1985 - July 1987 = 8-94152-892-0

don't have part numbers for earlier or later models but deep in my memory I think the left hand drive g200's MAY have had the same vac unit even though they had a different dizzy. So the septics might be worth asking.

Don't forget a visit to your friendly Holden Rodeo or Jackaroo wrecker might be a solution. All the 4zc1 and probably 4zd1 and 4ze1 engines would have had the same set up I would think.
So many cars, so little cash

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Post by eyecon » Mon Jan 03, 2011 9:18 am

IZU069 wrote:My neighbour has my vac advance (in his Toyota!). I'm waiting to get to a wreckers to get the proper one (instead of $70 or $170 whatever for a new one - that's called "get a Jaycar electronic timing kit instead"!).

Keep the Jaycar kit in mind = ~$99 for 11-step progammable vac & speed advance, though it requires a hand programmer (~$65?).
The Jaycar kit sounds good m8, but does that mean you have to continually adjust the the thing whilst driving? That would be a nuisance. Or is it something that requires the car to be put on the dyno for tuning and final setting up?

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Post by IZU069 » Mon Jan 03, 2011 4:04 pm

Nah - you set & forget.
You can load with standard curve figures. (And tweak from there.)
It can be used to replace or modify any dizzy etc.

Considering a dizzy rebuild & curve usually costs $200-$300... and that's only a single- or dual-slope curve for each (speed & vacuum)...
And THEN you modify something....

The kit has an optional knock sensor too - handy for tuning purposes. (But as SiliconChip says, should not be used for to keep in "max performance".)


Then again, a $40 Arduino might be easy enough to program... then add "smart" sequential (no CAS required)... and self tuning....
Oh no - here I go again!

[ FYI - when I got "revolutionised" into web forums circa 2005, I was being told by "experts" and new graduates what could NOT be done with electronic ignitions etc. I tried to convince them otherwise, and I even started updating an old 1980's project (electronic ignition with self learning/tuning) for EFI. Then I found out that what I said had been happening with OEM since ~1990. Since then, the "expert ignoramus" count has steadily increased.
Isn't it fun being out of something for over 20 years and finding the "world" is sill way behind? (NOT!!!) ]



PS - the Jaycar/SillyChip kit is single input/output and not suited for sequential. (Ok for wasted bank & spark though.)
But I think I figured out how to use it for a wasted spark (2 bank) or sequential etc.
That was back when I considered a multi-fire CDI (a DC PSU plus about $2 per input/output) but then found the "primitive" (LOL) RB Gemini etc reluctor ignition system. Since fitting that, I haven't bothered with CDI & programmable ignitions. (And since finding Delco, I haven't bothered with my EFI system.)
Oh the arguments come back to mind - "reluctors" are "inaccurate" (because they are AC LOL! In fact the opposite is true - they are the most accurate - not that the difference matters!), or that you MUST have a mechanical "CAS" for sequential ignition, or even that you must have a CAS for EFI (eg, suckers that spent fortunes putting Camira dizzy tops on Geminis etc when the Camira is the same as an RB Gemini dizzy except the RB is newer & superior!).
But that is now all so last decade....
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Post by eyecon » Mon Jan 03, 2011 4:27 pm

Love the idea of self learning/tuning electronics. Always thought the standard dizzys were a hindrance to real performance gains. Can't recall there was any of this stuff on the market when I had my car, otherwise I would have gone that route.

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Post by IZU069 » Mon Jan 03, 2011 5:03 pm

LOL! The Aussie Piazza release was around the time designed my ignition - the 20 year old Bellett dizzies were getting a bit worn (and no way was I gonna spend $hundreds for dizzy rebuilds!). It was a distributorless flywheel timed thing with an auto-learning/tuning mode (albeit semi-operator else mode dependent since I didn't know (enough?) about knock sensors back then.

The only thing that changed since the mid-1980s was figuring out how to not require dismantling for a flywheel reference mark (I was going to use an embedded magnet). Oh - and upgrading from a 6511 or 68HC11 to a 32-bit MPU for cheapness & power (esp for EFI learning) as well as voice control etc.


Anyhow, the SillyChip system and its Jaycar links....
You need the base module, plus a way to program it (a modified hand controller). Then there is optional ignitor (too expensive!!) and knock sensor circuit.
Separate to that is the vacuum sensor and knock sensor.

It was the hand controller that made me think of the Audrino - that's a full CPU (not a space-limited PIC like the SillyChip kit) with USB interface. Program whatever you want (once you know how!).
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Post by eyecon » Mon Jan 03, 2011 5:48 pm

Man if I do go that route I think I will just ask you to make up one of these Audrino's. Pay you of course. LOL would that come with warranty?

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Post by IZU069 » Mon Jan 03, 2011 6:47 pm

Warranty? What for? My programming is bug free!
(That's not as stupid as it sounds - even at assembler level)


I actually got the Arduinos because I was modifying a Gemini dizzy for sequential & wasted ignition (for Belletts, twincams etc).
Despite being EASY in principle - ie, a $4 hall-effect chip & a magnet, a CD4017 chip and jumper or switch to select whether one output to a dizzy, or wasted 2x2, or sequential 4x1 output - it was mechanically tricky.

As usual I ended up with a software solution - the quarter-century old "smart" CAS (you know, the one that can't be done these days for some reason... Ah - the forgotten art of software solutions and the smarts that used to go with that! Ain't greed a bitch?!).

But since the external interest was minimal, the Arduinos made it to my mantel shelf. (One of those recent religious cards may have knocked them off - the mantel piece uses a FIFO system.)
Alas since I use a LIFO system - and programmable ignition was last touched a few years back (with a "demo" mockup system touted in 2006, and the original ~1986 design with EFI Design planned for my trip in 2005 (which has yet to occur...)....) ... yeah, one day.

I haven't even gotten around to sussing the Arduino architecture (memory map etc) as opposed to the ATmega328 chip it uses. I did look at the ATmega instruction set, but decided it's better doing the coding rather than pre-learning (ie, my usual tactical research & solutions, aka JIT etc).
Alas new processors etc involve a learning threshold, and I'll do that when I have the need...
And when I think about that, I start thinking how much easier it would be developing my own EMS instead of using other restrictive systems.... That's put me back 6 years to 2005...., so maybe in 2016...?
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Post by eyecon » Mon Jan 03, 2011 7:10 pm

Dude you're doing my head in with some of that crazy voodoo talk :) At least you know what you're doing. I'll need someone like you to to get it working. Way out my league. All I want to know is whether it will run better than the original setup. That and how much better and reliable it will be.

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Post by IZU069 » Mon Jan 03, 2011 8:43 pm

The way I see it, it can't be worse.

IE - get the original vacuum and speed (aka mechanical advance) from the book.
Program them into the ~$99 ignition kit.

That will not change as springs weaken, diaphragms soften, movements seize & get sloppy.


The bonus is that you can tweak it for the humps and dips that the mechanical mechanism does not cater for.
But that might be for those that set timing by ear - others are happy with "un=wearing" book values. (I never set timing by the book since that is a retarded (no pun!) safe setting which does not vary with engine age & changes, fuel, temperature etc. I instead set for max efficiency/power.)

Just lock the dizzy and go. (Lock - as in disconnect or block the vacuum advance & seize/glue the central shaft or lock the flyweights with a big washer with 2 holes (to hold the flyweight spring pins.)

Not that the dizzy needs locking - it can be programmed to replace the flyweights, or the vacuum advance, or to modify either or both. (EG - keep the speed advance and only program the vac advance.) But the dizzy's timing can't just randomly bounce around.


You should be able to use the Piazza's ignitor, but some checking is needed...
Since the 4ZC1-t Piazza is (presumably) some recalcitrant design, it uses mechanical dizzy advance with an ECU-controlled knock retard, hence the ignitor isn't the typical "reluctor" dizzy input and IgCoil output - it also has a digital ECU retard input. (If it were the earlier I-TEC design, it would be a locked dizzy with a "digital" ignitor which gets its spark signal from the ECU.)
But ignitors can be modified for either input type, though reluctor types are usually easiest (a mere capacitor and resistor(s) instead of zero-crossing sensing added to "digital" ignitors.
(Digital ignitors are those that use a square-pulse input from an ECU or optic or hall-effect sensor. Reluctor-fed ignitors have a zero-crossing detector (conventionally on the negative going crossing) that triggers the ignitor.


Save your head. Don't try too hard to understand. You can if you want to, it just takes time. (And written is tedious - a 5 minute verbal kills days of ping-writing-pong, and the need for codeine.)


But there are lots of ignition options. The 4Z dizzy is common and it shares main components with other vehicles. The G-series dizzy components are the same except they rotate in the other direction.
And IMO, there are other springs and vacuum advances that are "close enough". (Weights are usually all the same.)
And as I found, a standard uncurved Gemini dizzy with RB guts (aka "the RG dizzy") is superior to most Bellett/Wasp/Florian dizzies being used today (as measured by fuel economy & performance).

[ FYI- A Gemini electronic dizzy that recently sold for $170+ on eGay used 4Z reluctor guts or similar - ie, a sensor and internal ignitor for a clockwise rotating dizzy instead of the Gemini T- & RB-series counter-clockwise rotation (ie, G-series and whatever FWD RB series engines). The joke was the dizzy had been listed for years at $150. It finally re-listed for $170 and had 2 bidders! Most convert their Gemini dizzies for free, else ~$35-$45 for an (early) RB dizzy. ]


Whilst I've been waiting for "specials" on the Jaycar ignition kits, I now suspect instead that they will soon cease to exist. As I found when offering "superior" solutions - and ironically cheaper and often with "standard" parts - people seem happier to spend $hundreds reinventing old technology or "their own" new solutions. (Just look at EFI dizzies, or $600 Pertronix ignitions, or older Isuzus with crappy old twincam & G-series "plate" dizzies or Gemini points, or Delcos and others with Nissan N13 or Camira reluctors! Or the SiliconChip multispark CDI for $150 - people still preferred $300 for a plan MSD or $600 for the MSD+ whatever; though that SillyChip CDI is now way outdated with the advent of cheap dc-dc converter chips.)


If enough interest exists, it'd be worth tailoring that Jaycar solution for the Piazza(s). (I have the original articles.) And "grouping" together for shared programmers etc. (I'd rather have 2 ign units than one unit plus a programmer...)

But I can imagine a $40 Arduino to which people plug in their ignition interface, and can program thru email thru USB etc.
Oh no - that reminded me of another project - Piazza digi-dash repairs. (Hello Bob!)
2 stages:
1 - PSU replacement.
2 - "guts" replacement - keep the displays & drivers but scrap the rest & replace with a CPU. Again - 2 stages - 2a mimics original dash functionality; 2b adds extra functions ... whatever - like new alarms; speed alerts; average, trip, historical readings; etc - anything the standard dash could display; plus a USB etc interface for external PCs or displays and setting user preferences.
That 1980-vintage dash multi-level(PCB) circuitry can be largely replaced with one MPU. (They remind me of the old ~1976 G180W EFI "analog" controllers - twin PCBs with round metal Op-Amps etc.)

But that's all Bob's fault - he got me a Jackaroo so I don't have to worry about my Piazza's. Hence my Piazza interest is now academic only, or if my mum needs a fallback vehicle. (She too loves style. Besides, she has Isuzu rallying credentials.)


Alas my vintage OP Bundy is getting to me.
Point is, you probably needn't worry.
Points are, I tend not to do, but teach instead. Hence if you can solder... or want to learn, and can then catch your own fish....
But maybe I should "go pro". I'm now on the dole (workcare? newfart? or something...) and it ain't covering rent AND bills and food....
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