Minimum hookups to get spark?
 

I finally got my Turbo project spinning...

With the starter anyways. I'm seeing 3 positive strokes on the rear rotor and 2 on the front.

I would like to fire her up and try to get the side/corner/whatever seal to free up and give me solid compression on all 3 faces on the front.

Anyways, I have a minimal amount of electronics and other gadgets hooked up (I have a Megasquirt v2 that I plan to use, just haven't installed). These include:

1. Battery posi to fuses and posi to starter
2. Main ground to block (from battery)
3. Coils (both coils "plugged" in)
4. CAS
5. Plugs and Wires

Do I need to hook up the alternator to get spark? The water pump is not yet installed... (I have no plans to run the motor beyond a few quick startups using starting fluid, the fuel pump is currently disconnected).

Any help is greatly appreciated.

Thanks,

Josh

No, you don't need the alternator to make spark, The cas has to be plugged into the m/s, and map set up, and of course duh coils.

I just want her to fire up and run for 3-5 seconds on the stock NA ECU (No megasquirt, yet).

So I finally found my digital meter and started taking Voltage readings...

All 4 connections (1 white connector) to CAS = ~12V
Both wires (B/Y, G/Y) to lead coil = ~.3V (when i turn the CAS, there is no voltage jump?) yes, that's 3 tenths. (all tested with key in ON position)

After doing some searching, I feel like the issue is a grounding issue at the ECU, . I will have to check the rest of it this evening.

Grounds connected:
Bat negative hooked up to long starter bolt on engine side.
also grounded to fender wall
Ground under UIM, grounded to UIM temporarily (Voltage tested good)

All fuses are good. (engine bay fuses all good, engine fuse in car good).

This is an S4 w/ NA harness btw.

I guess my question is: Is it almost 99% likely it's at the ECU or an issue with my harness based on the info above?

If so, I'll just order the DIYAutoTune harness and run new grounds and everything for the MS. Which means I'll have a Megasquirt S4 harness adapter available FS ;)

Thanks,

Josh

B/Y should have battery voltage w/key to on. G/Y would have no voltage and then spikes to 5 volts then back to zero. Is your main relay operating properly? The B/G wire at the engine fuse box (40 amp fuse) would have constant voltage so check this wire and respective fuse, and its voltage would be passed onto the B/Y wire w/key to on. Main relay might not be grounded properly. Two wire plug connected to it houses the B/W wire (15 amp engine fuse) which is to supply voltage to the relay when key is to on and the Black wire provides the ground which is found grounded to a metal adapter w/multiple ground wires located under the trailing coil. Also, spinning the CAS might be to quick for the multimeter to register a proper value so you could manually crank the main pulley and this will provide you with an accurate reading of what's going on with respect to the G/Y wire.

Thanks, Satch.

I'm out of the office in 15. Plan to go out to the shop and sniff this out.

I might not even have the "main relay" hooked up. I gutted the entire engine bay before moving 2 years ago. Rebuilt the motor, then had to move. Lost ALOT of parts in the process =(.

The other wire coming out of the main relay which would be the B/W wire provides voltage to the emission components and eventually ends at pin 3I (main relay) of the ECU and this is how the ECU is powered up I do believe.

take a spare CAS and plug it into the harness (Key in run position). Spin it by hand and see if you get spark. or pull the one out if you don't have a spare.

It was totally the set of ground wires under the coil.

I painted over the "bracket/plug" when I did the engine bay. Just figured that loose plug as one of MANY.

Thanks alot, satch!

Good to hear. Send me that bag in your avatar and we'll be even.