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Showing results for tags 'tach'.
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Alrighty, Ive got a stock 1978 280z and I'm currently installing an MSD 6A and Blaster 2 coil into the car. After reading any and all forum posts on the topic I came to the conclusion that I would need an MSD Tach Adapter 8920 in order for the MSD box to Communicate to the EFI by upping it to 12v. All my wires are in place and I'm getting a good strong spark. I put a voltmeter on the purple wire coming out of the MSD tach adapter and I'm getting 12v. Only problem is that I'm getting no fuel. It must not be communicating with the EFI somehow. Here's my Setup. MSD 6A: Heavy Red goes to battery + Heavy Black is going to battery - Red is going to Black wire with white strip (Ignition Key Wire) Orange is connected to blaster 2 coil + Black is connected to blaster 2 coil - White is not being used, I do not have a points system Violet and Green are connected to the Magnetic Pickups (I was told it didn't matter which way, I put green to green and violet to red) MSD Tach Adapter 8920: White goes to Tach Output on MSD 6a box Black is ground wire Red is connected to Black wire with white stripe (so two reds and black with white stripe all connected) Violet is connected to the blueish green wire that was connected to the coil negative terminal. Summary: I don't know what the **** I did wrong. Someone please tell me.
With my seating position, my small-diameter fat-ring steering wheel is blocking my tach view right in the key areas. OK for DD but already at the first autox I had to keep hunching over and was undesireably encumbered. So I'm looking to make a shift light/indicator for my 72 240Z. Still in the concept stages and any suggestions/resources/corrections are greatly appreciated; I've found a surprising lack of any information of this kind. Im aiming at passive electronics, but may consider Arduino. I'm comfortable with either but mostly just would like to figure out how such a shift light indicator would work when fitted to distributor ignitions - ie what that signal looks like coming off the coil, or similarly even just how a tachometer works in that sense. So really the key is confirming that it is a 12V square wave with frequency reflecting that of all spark plugs firing. I have a multimeter but no data collection hardware at my house. I presume its 12V at the positive terminal where the tach connects. I have a 3 ohm coil, no ballast resistor. I have an electronic dizzy but thinking about it as points seems viable and simpler, so my thinking that I'd like to verify (please correct if wrong): voltage builds in coil when the contact is closed then releases into plug when it opens. so i would think there would be 12V at the input terminal when the contactor is closed and goes to zero when it fires - thus spark signal could be considered a falling edge triggered event. Although necessary to make sure I'm thinking correctly, that level of detail isn't really functionally necessary as all we need is frequency of this signal. I could just determine the RPM I would like the light to go off at, then correct to 'revolutions per second' then multiply by 3 (inline 6 = 3 ignitions per revolution) and we have target cutoff frequency to design circuit for. Right? I havent thought through the circuitry too much yet but generally seems like it would just be: high pass filter (tweaked to frequency) --> inverter --> light (?) Arduino may have the advantage of multiple RPM set points without having to reassemble the circuit. Then just use whatever kind of light - maybe even under the windshield vents as a HUD As I said any recommendation / correction / resouce is welcomed. Thanks in advance. Ben