So...I messed up..
...I was attempting to reset the "inspection" light on my dashboard and after doing some research I discovered the ol "ground pin 7 on the OBD port" trick... so I did, only to realize that I had grounded pin 7 on the C101 instead of the OBD port.. I've impressed myself with how stupid that move was... now the car won't start..
What I have done so far to diagnose the problem:
-Checked the fuses and replaced any related to the fuel pump/ignition system just for good measure (none were blown)
-Jumped the main power relay and the fuel pump relay independently and simultaneously
-Checked for spark at the plugs, no spark (I should probably jump the relays then check for spark.. just realized that now..)
-Swapped in unimportant relays from my fuse box [like the high beam relay (5 prong, matches the main power relay) and the low beam relay (4 prong, matches the fuel pump relay)] to the little module that holds the three main relays, no hum, no clicks
-Attempted to jump my car's battery with another car's battery (my dad's idea, still not sure why he suggested that.. my E30's battery is new and is giving me power)
After doing some research, pin 7 in the C101 is responsible for the fuel delivery system, and a lot of the ignition system. The car cranks and cranks but it sounds like she isn't getting fuel. I've jumped out the main power relay and the fuel pump relay and when I do I hear a hum and clicks from the engine, as if the fuel pump is giving the engine fuel, but when I turn the key with the relays jumped I still get nothing.. I don't think it's the fusible links because my dashboard still lights up, and my headlights still work. I've heard it been said that basically if I have power to anything, especially interior lights, then my fusible links are fine.
What I suspect it to be:
Fuel pump is either fried or is not receiving power.. if it's not getting/giving power then that could mean there's a short in its power supply or that it's toast..
ECU is fried (possible but not likely, as everything else electrical works on the car)
Crankshaft Position Sensor (CPS) is fried and isn't giving the plugs spark
There's a short somewhere along the lines after the relays/fuses or the relays are shot and I jumped them incorrectly(?)
Distributor cap is blown(?)
I've tried narrowing it down as best I could, my next step is to tear the car apart and test the fuel pump for power, and if it has no power then to examine the lines all the way to the front of the car to check for a short.. I don't have much of a head for electrical stuff and I'm not even sure if incorrectly grounding pin 7 would cause a short somewhere somehow, or even how it has effected the car's electrical system.. Before I disassemble the car I'd like to see if anyone out there smarter than I could help me narrow down what I should be looking for. I've pored over diagrams that trace where the power is distributed starting at the battery and ending in any component that is related to ignition or fuel and I'm a little overwhelmed. I've ordered a main power relay and a fuel pump relay just for the hell of it, but while they're getting shipped here I want to diagnose the problem.. not being able to drive my baby has taken its toll on me..
...On a good note, I found the actual OBD port and grounded pin 7 which successfully reset my dashboard inspection light......
This is my first post here, but I've seen how helpful this community is and I've learned so much just from browsing the forums, so I'd like to preemptively thank you for taking your time to help me out here
I've got an '89 325i auto cabrio
...I was attempting to reset the "inspection" light on my dashboard and after doing some research I discovered the ol "ground pin 7 on the OBD port" trick... so I did, only to realize that I had grounded pin 7 on the C101 instead of the OBD port.. I've impressed myself with how stupid that move was... now the car won't start..
What I have done so far to diagnose the problem:
-Checked the fuses and replaced any related to the fuel pump/ignition system just for good measure (none were blown)
-Jumped the main power relay and the fuel pump relay independently and simultaneously
-Checked for spark at the plugs, no spark (I should probably jump the relays then check for spark.. just realized that now..)
-Swapped in unimportant relays from my fuse box [like the high beam relay (5 prong, matches the main power relay) and the low beam relay (4 prong, matches the fuel pump relay)] to the little module that holds the three main relays, no hum, no clicks
-Attempted to jump my car's battery with another car's battery (my dad's idea, still not sure why he suggested that.. my E30's battery is new and is giving me power)
After doing some research, pin 7 in the C101 is responsible for the fuel delivery system, and a lot of the ignition system. The car cranks and cranks but it sounds like she isn't getting fuel. I've jumped out the main power relay and the fuel pump relay and when I do I hear a hum and clicks from the engine, as if the fuel pump is giving the engine fuel, but when I turn the key with the relays jumped I still get nothing.. I don't think it's the fusible links because my dashboard still lights up, and my headlights still work. I've heard it been said that basically if I have power to anything, especially interior lights, then my fusible links are fine.
What I suspect it to be:
Fuel pump is either fried or is not receiving power.. if it's not getting/giving power then that could mean there's a short in its power supply or that it's toast..
ECU is fried (possible but not likely, as everything else electrical works on the car)
Crankshaft Position Sensor (CPS) is fried and isn't giving the plugs spark
There's a short somewhere along the lines after the relays/fuses or the relays are shot and I jumped them incorrectly(?)
Distributor cap is blown(?)
I've tried narrowing it down as best I could, my next step is to tear the car apart and test the fuel pump for power, and if it has no power then to examine the lines all the way to the front of the car to check for a short.. I don't have much of a head for electrical stuff and I'm not even sure if incorrectly grounding pin 7 would cause a short somewhere somehow, or even how it has effected the car's electrical system.. Before I disassemble the car I'd like to see if anyone out there smarter than I could help me narrow down what I should be looking for. I've pored over diagrams that trace where the power is distributed starting at the battery and ending in any component that is related to ignition or fuel and I'm a little overwhelmed. I've ordered a main power relay and a fuel pump relay just for the hell of it, but while they're getting shipped here I want to diagnose the problem.. not being able to drive my baby has taken its toll on me..
...On a good note, I found the actual OBD port and grounded pin 7 which successfully reset my dashboard inspection light......
This is my first post here, but I've seen how helpful this community is and I've learned so much just from browsing the forums, so I'd like to preemptively thank you for taking your time to help me out here
I've got an '89 325i auto cabrio
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