What this distributor gives the ECU
MSD (Holley) part number 2357 is a Chevy distributor with Hall sync. Inside it are two sensors. An 8-tooth reluctor with a magnetic (variable reluctance) pickup produces the trigger signal, one pulse per cylinder on a V8. A single-window Hall effect sensor produces one sync pulse per cam turn. That sync is what lets the ECU know which cylinder is which, so it can run sequential injection. Haltech doesn't sell this distributor, but it can be wired straight to a Haltech ECU as shown below.
Wiring
| Sensor | MSD wire | Haltech cable and wire |
|---|---|---|
| Trigger (reluctor) | Orange/black | Trigger 4-core, yellow (Trigger +) |
| Trigger (reluctor) | Orange/violet | Trigger 4-core, green (Trigger -) |
| Home (Hall sync) | Red | Home 4-core, red (12V+) |
| Home (Hall sync) | Green | Home 4-core, yellow (Home +) |
| Home (Hall sync) | Black | Home 4-core, blue (signal ground) |
The Hall sensor is powered, so feeding it backwards can damage it. On the reluctor side, reversed polarity won't hurt anything but can shift or corrupt the trigger edge. Check both before first start.
Software settings
Haltech publishes a screenshot of the trigger settings for this distributor. Need this diagram? Ask us and we'll send it over with advice for your build. After it's set up, confirm timing with a timing light and verify the rotor lines up with the cap terminals. Our pages on distributor rotor phasing and verifying TDC offset with a dual pickup distributor cover both. See also the MSD cam sync sensor and engine trigger systems explained.
