starter problem

[hyperman]

After redoing my car and connecting megasquirt my car won't start.
the starter is making a ticking noise but won't spool.
If checked if it was the battery thisi sn't the case cause it bought a new one and the problem stays. Next thing I checked was the starter itself, I replaced it with a second gand one but the same issue occurs.
Then I checked the ground wire of the starter but this wasn't causing the problem either.
Does anyone have a clue what the problem is, I don't have a clue.

[lakersfan1]

There is no ground wire on the starter. There's a main power wire, then a small wire to activate the starter.

The starter is grounded through the body of the starter, which means that the transmission needs a good ground strap to the body for it to work properly.

[nightnic]

The ticking noise probably means starter control cirquit is working, the tickling is from electromagnetic coil moving starter shaft back and forth. Same shaft when moved forth engages motor circuit which provides power to actually spin the flywheel. This indeed might be a grounding problem since motor cirquit requires much more current flow than control circuit.
Also theft-deterrent system might be engaged if operates on starter. As well as ignition switch wiring - I'm not sure whether megasquirt controls that, if yes, might be a good idea to double check megasquirt wiring.

*correction* mx-3 starter does not employ moving shaft, instead it uses clutch mechanism, but it doesnt change much in scope of the question.

[hyperman]

@ lakerfan1: i ment the one on the transmission. I cleaned that on so that can't be the problem.

Today i have tried to start without compression. and the starters works fine. but with compression it doesn't.

[nightnic]

Lacks power. measure the voltage drop on starter power circuit. Might be poor connection.

[hyperman]

I fixed the problem. It was the injector wiring that caused the problem. the starter tried to fire the engine up but the injectors didn't take over