I have a 02 Ep3, bone stock besides SRI and suspension. I started getting a misfire in cyl number 1. I pulled the plugs and number was fouled black. The other 3 were good. Compression is 180 across. I checked for spark with different coils on different cylinders and they're all good. Tested resistance across the injectors and #1 was 1.5ohm compared to 11.2-11.3 ohm for the test. 12v at all injectors and coils. Replaced that injector and plugs. Its still missing. I can unplug the number one coil while its running with no change. Any ideas?

 

So I found something, The ground signal on the #1 injector harness is leaking to ground. Where can I find some wire diagrams try to follow this thing.

 

So the ground leak is coming straight out of the ecu.

 

what do you mean by ground leak? You mean bad ground? Sorry I'm no noob just never heard someone say ground leak

 

Ok, correct me if I'm wrong.. at the ecu, Connector B pins 2-5 are your injector wires. You injector get a constant 12v. The Ecu then pulses the ground closing the circuit making the injector spray for how ever long the ECU tells it to. When I take Connector B out of the ECU, turn car to ON position and measure resistance to ground on pins B2-4 (Cyl 2-4 injectors) I get Infinity, meaning no ground. Pin B5 (cyl 1 injector) I am reading like 1200 ohms. Meaning something is wrong with the ecu because it should be infinity like the rest. This is causing my injector to be partially spraying all the time causing the misfire, fouled plug, and eventually the injector going bad. So I probably need a new ecu right?