Hey guys, the story goes, my 92 lego wagon wouldnt start this morning. Crap, ok well no big deal, look at the spark plugs and wire and remember i bought a cheap-o set a couple years ago, ok. Go to the parts store, "New plugs and wires, the best please". Back home we go, installed. No go. Just bit of a chug when i first touch the key then just turns over with no attempt at starting. I dig a bit deeper to check my MIL light, (its been on for some time now) and what do i find but the  black test plug is just left connected under there!! I disconnected it and lo and behold all my problems dissapear and it fires right up.

 

Long story short, does it cause any harm to leave the little black plug just connected all the time? Its not anymore obviously but i have been driving that way for about 2 years now and have had to fix clutch pack issues already. Just curious if that exacerbated the situation maybe, thanks everyone.

Black plugs should just be read memory connectors.

 

Will keep the CEL on....ussually flashing steady if no codes.

 

Should not affect starting.

 

Now the green ones.....that could.....they lock the ECU into an open loop/ static timing/fuel map.