interchangable distributors

General Bellett, Gemini 75-98, Piazza 81-93, Bellel, Florian, 117 Coupe, Minx, Aska technical discussion.
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Rodeobob
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Post by Rodeobob »

rodavo wrote:Bob,

Seeing as though you know heaps about Rodeo's.....

I am about to install a Motec M4 in my Piazza using the 4ZE1 dizzy for the ref and sync signals. What I am trying to work out is what ignition setup the Rodeo's ran and how the Rodeo computers sensed the engines exact position (if at all) using the slots as shown in the pic above. On many Nissan motors, the slots towards the centre of the disc would have 1 slot that is different in size to the others so that when this slot was 'read' the computer would know exactly where the engine position was each revolution. Looking at the 4ZE1 disc, the 4 slots in the middle are all the same. I am guessing that the rodeo ecu runs a batch fire injection setup with the rotor button and cap being in charge of the distribution of spark. Is this correct?

If so, looks like I will have to make my own disc so that the computer can reference the engines exact position.

Thanks

Dave
Yeah i know a little about Rodeos, i know dick about MT4's. lol.

Its Photoelectric. Photo meaning light which is converted to an electric signal. Theres an LED on one side of the disc and something that turns on and off as the light shines thru the slots and turns it into a wave signal for the ecu to read (lets call it a thingy, im not an electronics whizz. lol). I think theres two LED's one for each ring of slots. In the case of the nissan one mentioned with the one larger slot the ECU would read that as a longer wave.

Because the E1 is batch fire the ECU doesnt need to know what exact cyl is at TDC. Like nick and you said the cap and rotor sort that out. It only needs to know whats going on with load etc to vary the timing and fuel. This is the early type, the High Torque setups could have a different disk. I dont have enough data on them to know if they were sequential or not.

I would talk to an MT4 expert and be sure and know what your ECU actually needs. It would have to be a pretty flash bit of kit to be sequential injection. If it does need the No1 signal the disc would be easy enough to modify if your careful. If your after a known quantity you could try putting a Nissan style disc/internals in the E1 housing.
If your doing this remember that the 4Z timing marks for the belt (the ones on the dizzy for insertion too) all line up for TDC fire on No 4 Cyl. So you would want to fiddle with the slot opposite the one the timing marks line up for. If its 180deg out you cant just swap the leads because the ECU will be confused as to where the camshft is.

If you get your hands on a dizzy the RB30 has the same plug on the dizzy as the E1 does. Ditto the AFM and the TB and a few other things.

Cheers. Bob.
Too many Piazzas to little money.

Currently unemployed. Watch this space.
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rodavo
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Post by rodavo »

Thanks guys, that answered all my questions.

I am using a Motec M4 not a Microtech MT4 so yeah, its a good computer and can do sequential injection.

I've got a E1 dizzy already, so I may be able to elongate one of the slots, that will probably be the easiest way out of it.

Thanks

Dave
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Rodeobob
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Post by Rodeobob »

rodavo wrote: I've got a E1 dizzy already, so I may be able to elongate one of the slots, that will probably be the easiest way out of it.

Thanks

Dave
To be safe id run that idea past someone who knows about the ECU and also possibly someone who knows a lot about distributors just to make sure it will work properly.

If you do it right you might be able to ditch the dizzy cap and rotor and just put a cover of the distributor. If the ECU is capable of sequential injection it should have the capability of firing more than one coil.

If you do it wrong, well you will end up with a stuffed CAS disc.
Might be an idea to go grab a Nissan or similar 4cly dissy thats got the CAS disc in it. Maybe the Pintara's CA20 would be right, even if its not it would be cheap.


Bob.
Too many Piazzas to little money.

Currently unemployed. Watch this space.
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