electronic distributor

[sireland67]

Is there a way to bench test a factory hall type distributor.
Getting ready to build 2 out of one and have no history on the parts I am getting ready to use.

 

[TrailBeast]

Is there a way to bench test a factory hall type distributor.
Getting ready to build 2 out of one and have no history on the parts I am getting ready to use.

To check the sensor output, turn the DVOM to AC Volts. Rotate the wheel or whatever speed you are measuring. Place the meter leads across the sensor and measure the AC voltage output. Typically, if the shaft is rotated at about one turn every 2 seconds the output should be around .7 to 1.0 Volts AC.

 

[sireland67]

Sounds easy enough, but AC?

 

[67Dart273]

The Mopar 2 wire breakerless are NOT "hall effect." They are nothing more than a magnet driven pickup, and yes, they output AC spikes

 

[BillGrissom]

The Mopar 2 wire breakerless are NOT "hall effect." ...

True. I think Mopar changed to Hall-effect pickups around 1982. I think my Dodge Aries 2.5L had that. A Hall-effect would have 3 wires - supply, signal, gnd though they might have used the body for ground. Supply is ~8 V (at least in my 1996). We are all guessing what distributor you have. Why not state a year (or at least decade) and post a photo.

 

[RustyRatRod]

Chuck the shaft up in a cordless drill and stick your tongue to the wires. If you hit the floor, it's good. If not, throw it in the ditch.

 

[67Dart273]

True. I think Mopar changed to Hall-effect pickups around 1982.

Maybe the 4 whangers I don't know. None of the V8s or V6s (or slants) used Hall effect except the Magnums use it for cam sensor (in the distributor), these are crank triggered EFI/ ignition

 

[sireland67]

It’s just a stock 2 wire electronic.
I think it came out of my old 77 ramcharger, not sure I just picked the best looking one I had out of a box of them, sitting on the shelf for years.

 

[BillGrissom]

Then it is a simple 2-wire "variable reluctance" pickup. That is a permanent magnet w/ coil. It will trigger a GM HEI module or the Mopar 1970's ECU. A GM module is easier wiring (no ballast), unless your car was wired for the Mopar ECU (~1971+, why not tell us?). The 8-pin module is simplest and best. Grab the GM coil and cable that connects to it, and the pickup connector (2 pins you connect to your Mopar distributor), also has a "tach" output wire. Any 85-95 GM V-8 truck. Many youtubes of spark test setups and results. Read megasquirt site for pickup info. BTW, in current cars (at least 1995-2005), Ford's use VR crank pickups and Mopars use Hall-effect. The later gives a cleaner signal, but don't work if the 8 V supply is lost.

 

[sireland67]

I am doing a hei set up with the design to drive bracket, pentronix rev limiter hei module, 4seconds flat limiter plate.
Distributor will be used in a 70 Challenger with a 174 b&m supercharger, Small 150 shot of NOS.
5.38 gears, trans most likely will be auto, but also have a complete 4-speed set up.
Just trying to use some parts up.

 

[67Dart273]

Pay attention to pickup coil polarity and check "rotor phasing." Google it...........

The nice HEI diagram someone on here drew shows you, and you should check it anyhow

 

[sireland67]

67Dart, thanks for the pictorial, I always have to look it up, just to double check myself.

I have been running HEI set ups in mopars for at least 15 years now, they just work.
Its a no brainer for a cheap ignition.
I have 4 mopars now running the system, found the instructions years ago when running a slant in my old 71 d100.

This thread was basicaly, how to bench test an old unknown distributor that I had, to actually see if it works.
I sold the old truck it came out of 30 years ago, but it still tested good.

 

[KitCarlson]

You have to be careful about lean burn distributors. I think 1977 is lean burn era. Here are variations, but I don't know years, or application: locked rotor no advance, two pickups, limited advance, with and without vacuum pod. In testing I have done the VR signals, amplitude variations exist, resulting in timing timing among cylinders. The worst from dual pickup units were the signals mix due to flux leakage. The other variation on rotation angle due to runout, and remnant magnetism, from pickup magnet setting spot on reluctor.
If you DIY, using a Sharp optical vane switch, and Mercruiser reluctor works well. Points distributors good for core. I also like vintage Mallory Uni-Lite.