OK heres my situation and i know it was brought on by me but i still need help. I went to change the battery in my 89 CRX Si cuz it was very dead after leaving the light on like a thousand times(stupid civics and their lack of headlight buzzers ). Well anyways i also went to upgrade the negative battery post and wire cuz it was the original one and it was needing some love. Well instead of hooking up the negative post back to the block as Honda designated, for my better lack of knowledge i hooked the wire to a new ground on the frame and prepped it with sandpaper to ensure good contact. Everythings cool as i go to crank up the motor but nothing happens, i get the interior lights and all but no movement from the starter. So i think hmmm....i figured well maybe i should move the negative post back to the block, i do this and it starts, but runs rough and seconds later the map sensor code starts blinking and i get a check engine light, so i start to wonder what the heck? The car smells of gas and shoots gas out the tailpipe. I go to get another map sensor laying around for fear the battery hooked up and fried the map sensor, i plug it up and the same thing happens. I pull the plugs and they are black as coal. I put some plugs i have laying around and start the car back and it runs rough, throws the CEL again , and i give it gas and it hesitates but weakly runs,and i pull each plug wire out of the holes one at a time and they are throwing mad weak sparks(translated=weak occasional spark but still spark none the less). My conclusion is that i fried the ignitor(ICM) but my question before i blow 70 bucks on a new one is why did it do this(technically) and has anyone else experienced this before? And could it be the coil? Actually i am not sure what the coil and the ignitor do i just know the conditions they bring up when they are bad. Thanks for your time, luke

 

You need at least 2 grounds. One for the block you can use the tranny or the engine itselft and also need the battery grounded. Thats what I've done. Put the 2 grounds on and reset you ECU and that should clear all your codes unless the sensors are bad. I'm pretty sure you ECU gound runs off your battery ground.

 

thats a good idea but the thing is that i don't know why it would fry the ignitor, i didn't change anything but the placement of the ground so apparently this had to be the cause of the problem but i guess i will have to test another ignitor and coil in there( iam going to borrow one from a friend tomorrow).