Nissan Hardbody ignition conversion?

[nerdistmonk]

Hello everyone, ive got a bit of a project im trying but its giving me a headache so i figured i would ask for some help.

 

I have a 1986.5 Nissan D21 (hardbody), its been converted to a weber carburetor and has had all its sensors removed,

the truck runs pretty good, but i have been on a mission to remove the computer and make the truck standalone.

 

I was wondering what the best way is to give it a classic ignition system (like what most of the older datsuns have), i was really wanting to give it a magnetic pickup and do away with the ecu + optical sensor setup, (the reason being the transistorized ignition is half dead and is using the exhaust coil to drive the engine, its all i got left)

 

Would the distributor from a datsun 620 fit my truck? I found one on ebay that comes with a magnetic pickup preinstalled, but i am pretty sure the shaft ends are different, then theres the pertronix ignitor which is again designed for the 620 and back, idk if it will fit in my 1986.5's distributor.

 

I am sort of lost as to what i should do, so i am curious what my options are. (i read about the hei conversion and such, but i dont think that applies to this truck)

 

Any help would be appreciated

 

-monk

[datzenmike]

The CAS is far more accurate.  But it can't be working properly if you have a weber on there... the throttle position sensor will be missing and a few other things to generate the proper advance... too bad.

 

 

Just get the 8 plug distributor from an earlier 720. It's a magnetic pick up designed to fire two coils like you have. Similar in function to the even earlier 620 but for dual coils. BTW dual coils are the way to go.

[nerdistmonk]

Ok i found what you were talking about, i found a used one for $50 and man does it look used... will the z22's dist fit in my z24 engine?

 

edit: also im guessing once i have this item (assuming it fits) i do the chevy hei conversion straight to an aftermarket coil with 3.0 ohms resistance (which means no resistor) and bam?

[datzenmike]

Actually the truck runs great as is, as the ecu on the d21 has a alternate method for timing in the event of sensor failure (which im using), the truck drives good but i dont like the computer and i dont like expensive components that are hard to find (like the modules and such), also the dual coils have zero effect on performance and were there for emissions reasons (they fire on the exhaust stroke and only when below a certain rpm)

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Yeah that tale has been around a long time and is not true. Both coils fire together and at all times. Period!

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Also the 720 has the same optical sensor my d21 has (z24 engine), it also has a similar computer,

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The last half or the 720's '86 production year did use the same fuel injection set up as your D-21. Both motors were called the Z24i... earlier 720s were simply called the Z24 and were completely different and ran carburetors. Check your engine compartment tag over on the passenger side inner fender under the hood hinge. It will say the motor is a Z24i not Z24.

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nissan never had a magnetic ignition they went from points to optical.

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Who told you this? All Datsun/Nissan from '78 on used a magnetic pick up and and amplifier to trigger the coils(s). Any Z22 or Z24 distributor from an earlier 720 will fit your Z24i and work both coils. You will have to get and swap the drive spindle too. The Z24i spindle is splined.

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So again i ask what am i supposed to do, the 720 dist wont do much for me it seems. and i do not know about making a 620 dist fit.

You don't want a 620 distributor. It only can work 4 plugs. I highly recommend having all plugs working. Check out drag racing motors. They modify the HEMI motors to run dual plugs. Ask any racer if they would run dual plugs if they could, would they? They would all say yes. Can't be for emission purposes can it? If shortens the burn time, reduces pre ignition allows less timing advance, is more efficient and because of this, it pollutes less.

[nerdistmonk]

Ok i found what you were talking about, i found a used one for $50 and man does it look used... will the z22's dist fit in my z24 engine? (all the z24s had optical sensors i had to go all the way back to 1982 to find the z22 based 720 with your magnetic pickup in it)

also im guessing once i have this item (assuming it fits) i do the chevy hei conversion straight to an aftermarket coil(s) with 3.0 ohms resistance (which means no resistor) and bam?

 

Also how would i go about powering 2 coils with this one dist will it have the wiring there for 2 of them? (im guessing i would need 2 of the chevy hei modules aswell)

 

But the one important thing is will a z22 dist fit on a z24? (ive seen that ends are different on some of these dists depending on the year)

[datzenmike]

The only optical distributor used on the 720 was with the Z24i motor from April '85 and just barely into the '86 production year. ALL before that were electronic ignition.

 

No you do not need to do an HEI 'conversion' to it. It's ready to go as is. There should be 3 wires to it.

 

One is POWER from the ignition. The other two switch to ground and connect to the coil negative terminals. Power from the ignition goes to the positive terminals. Your D-21 should already have the two coils and the power to them.

[nerdistmonk]

The Conversion was a complete success, works like a dream.

 

Please refer to my project thread for details> http://community.ratsun.net/topic/55847-my-datsun-hardbody/