Stick figure

Different ignition

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EFI, ECU, microprocessor, "computer", "control",,,  there are a lot of words being battered about here.  The control algorithms coded in to the microprocessor circuitry would tell how much "computer control" was happening.  Just because there's a microprocessor in the ECU doesn't mean it was "controlling" the whole system.  It could be doing one small part, like handing the O2 sensor data.  Response speed would be important for its role in the system.

The original question was about the distributor being "computer controlled".  Even if there is a microprocessor in one of the EFI ECU's, it wasn't used to control the ignition system. 

Just trying to keep things clear.

 

Don't want to get in to this guys world - https://www.performancechiptuning.com/nissan/240z/

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4 minutes ago, Stick figure said:

I kinda thought about 80s computers and today's technology. Atari vs Xbox 

Your's is Atari at best. The ECU controls the fuel injection. The computer tells that you left your lights on, if you want to call it a computer.

Seems to me you want a Japanese car to to behave as a SBC. It doesn't from all I've read. They're different but we'll help as much as we can. Don't get tunnel vision or blinders on. So many options for your car.

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19 hours ago, Captain Obvious said:

And take a pic of the microcontroller.

That would be nice to see!  and a copy of the circuit diagram too!  Very interesting..

19 hours ago, Captain Obvious said:

6802 is just a processor.

Yep!  Just like the 6810!  That was the processor found in the commodore 64!  ( in 1985 i builded a plotter that was controlled by the commodore 64!)

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So we're clearing into the academic portion of the thread, but I got some pics...

Here's the ECU that I took out of an 83 NA with an auto trans:
P1160131.JPG

Here's a pic of the inside:
P1160132.JPG

And here's a close-up of the microcontroller. Hitachi  HD6801VOP. Also note that you can see the 4MHz crystal in the lower left corner of the pic. Now granted... Just because there's a 4MHz oscillator doesn't guarantee that the microcontroller is actually running at 4MHz. I don't know if they are dividing that down or PLL looping it up. But my assumption is that the microcontroller is running at 4MHz  :
P1160133.JPG

And since I had the camera out... Here's the ECU out of an 82 NA with a 5-speed trans:
P1160135.JPG

And the internals are still analog voodoo:
P1160137.JPG

So my (one and only) data point seems to indicate that they went to computer control in 1983.

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So is there only one circuit board in the microprocessor ECU?  Not a board sandwich like the early ones.  Did they shrink the package down, the processor replacing a whole board's worth of components?

Would be interesting to see what is connected to the processor.  Might also be interesting to compare it to an ECCS ECU.  See if it's a step on the progression.

Somewhere out there is a list of what some of the components inside the early ECU's do, their functions.  Resistors, capacitors, etc.  superlen has seen it, I think. @superlen

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20 hours ago, Captain Obvious said:

But my assumption is that the microcontroller is running at 4MHz

In 1985 a commodore 64 ran on 1 Mhz..  It could be possible that this 6801 ran on 4..  take a scope and find out! 🤣

I once opened an '79 280zx "ecu" and it had a few round 10-12 wire (in a circle) "integrated circuits", the precursor of the integrated circuit as we know them today.?

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16 hours ago, dutchzcarguy said:

 take a scope and find out! 

I once opened an '79 280zx "ecu" and it had a few round 10-12 wire (in a circle) "integrated circuits"

Lol. I could do that. But it would be waaaaaay down on my priority list!

Those metal can circular integrated circuits were used starting in 75. The pins were identified with letters "A", "B", "C", etc instead of pin numbers 1, 2 , 3.

Precursors to the plastic DIP. This one is from 77:
P1060898.JPG

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5 hours ago, Captain Obvious said:

This one is from 77:

It looks simular to the '79 i saw..  Funny those cooling devises on the "IC's"..

Btw... we talked about the 6801 and 6802...  I made a mistake.. i learned to program 6502 not 6802 and the commodore64 had a processor that was close to that one, the 6510!  But the 6802 probably has the 6502 processor in it..(?) besides rom and ram..  (I think i start a thread pure about the different controll units in a 280zx one of these days..) 

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Where I've only been interested in simple carbureted engines, I've never felt the need to learn anything else, points ignition, one wire alternator and a starter was all I needed or wanted. It took me forever to even use a hei distributor. It's only ever been 50s 60s and early 70s cars and trucks, but I absolutely love this rotted out datsun. I've owned some awesome prostreet cars, hot rods, rat rods, but I've seriously connected with this car. I feel like a new student in an advanced calculus class that had a D- in basic math.

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Stick, Yes... We have clearly veered into a purely academic avenue on your thread, but we're good clean fun.  LOL  We'll help with the math.

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Well, the weather is half way decent today so I decided to start cutting out some rust out of the passenger side floor and so called frame, I have nothing left. I have the seat brace left. I know there is a rust section somewhere on this site, I don't want to be posting where I shouldn't. I watched b is for build 240z project where he built a full frame. I'm considering cutting the whole front off and doing a subframe. Anyone ever do this here?

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With the unibodies sometimes the pieces you think are important aren't so much.  Don't think that you need big solid frame rails for the car to be solid.  The car is a steel box, with a few reinforcing pieces attached strategically.

Many members here have cut away large sections of their cars to repair the rust.

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On 11/17/2019 at 8:16 PM, Stick figure said:

the weather is half way decent today so I decided to start cutting out some rust out of the passenger side floor and so called frame, I have nothing left.

Sorry, but i had to laugh at that sentense..    I also once had a (ex)car like that… it was a Dutch Original car.. these are mostly all rotted away..  I had 2 giant holes sawn in the floor.. If you do that look if you have to brace it.. there is nothing so bad as finding out the door won't fit after you welded a new floor in a car.  (never had that myself luckely)

Pic. 2 looks not scary.. the 3th.. does a bit... If i were you i would look for a clean chassis.. they must be around for not to much "Dinero" ? as we overhere say: Pegels!  hahaha..

Edited by dutchzcarguy
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I'm sure you know but a lot of us have found it's best not to cut out all the rust at once, it makes the body flexy and sag if you're not careful.  Better to repair the P/S floor first then onto the D/S floor pan then the dog legs and so on.

That is certainly true for the 240z's and maybe not so much for the ZX's because they are a little stronger but just thought I would mention it, as dutchcarguy says, you don't want to weld in permanent errors.

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I thought of that beforehand and blocked it up but surprisingly it didn't move at all. I guess they are pretty strong little cars. I can piece in 1/8 inch plate where everything is cut out. The only thing that worries me are the metal lines running down by the transmission tunnel. I hate welding that close to them. I hope after I unbolt them, they will pull out of the way some. I still have a few spots to cut out. I want this car 99 percent rust free. The rear of the car underneath isn't that bad. Getting the undercoating off is the hard part. If all fails on the patch work, I'll do the car like kamikaze garage did voodoo.

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9 hours ago, Stick figure said:

I hate welding that close to them

Haha.. remember an old friend.. he was welding with acetylene under a Mercedes S class..  welded through the fuel lines ones.. (on one spot they had a sort of plastic part in the line he did'nt know about.)  The fuel came out at very small amounts and every time the line catched fire he blew it out !  Haha.. yes with his mouth! 🤣

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