Hello

I have a 93 volkswagon passat GLS VR6. i'm having problems with a rough idle and and occasional stalling on hills when starting from a complete stop or sometimes when i push the brakes to stop it will shut off. especially when its cold. The Abs light is always on...The red one on the left side and the orange one flickers on and off when pressing the brakes. i took out the brake relay which makes a clicking noise when pushing the brake to try and eliminate the abs but then it seemed like the power booster wasn't working at all then so i didn't want to take it for a test drive...Any ideas or things i could try with this

also i tested the spark with a spark tester and the spark is good on every wire but seems a little weak...changed the coil and it didn't do anything. but also whats really weird is when cranking the engine there is no spark at all. And the engine actually won't start until you let go of the key. then the spark kicks in and because the engine is still spinning it starts.
Any ideas about this or suggestions?...previous similar experiences?...someone suggested replacing the ignition module

any help appreciated
thx