Unexpected problem!
Posted: Sun Jul 09, 2017 3:36 am
I've recently been suffering from misfires under load and traced the problem back to water inside the power loom. Some of the 12v and grounds were corroding quite badly so I pulled the whole power loom out and replaced around 50% of the wiring. Whilst I was replacing things I decided to upgrade the the two main ground's coming from pins 13 and 14 on the ecu connector as they were only 0.5mm wire, I upgraded to 0.75mm wire.
I installed the loom back in the car and the engine fired up no problem, but I have constant rpm drop outs, every 1-2 seconds rpm will drop to 150 and back up to 1000 again.
The sensor loom hasn't been touched and I find it hard to to believe that a crank sensor has failed but I won't rule it out.
My gut feeling is electrical interference from the coils, maybe the wiring was holding them back and now they're producing a stronger spark with more interference. I'm not ruling out water in the sensor loom either but that crank sensor is one continuous shielded cable all the way to the ecu so I think it's unlikely.
The ignition system has coils mounted on the bulkhead with long ht leads to the engine, the leads are copper! (been copper for years). The plug boots have about 5kohm resistance and i run ngk Resistor plugs. My first thoughts are to change the leads for resistance type.
Anyway it's very strange and It's got me baffled, for now
I installed the loom back in the car and the engine fired up no problem, but I have constant rpm drop outs, every 1-2 seconds rpm will drop to 150 and back up to 1000 again.
The sensor loom hasn't been touched and I find it hard to to believe that a crank sensor has failed but I won't rule it out.
My gut feeling is electrical interference from the coils, maybe the wiring was holding them back and now they're producing a stronger spark with more interference. I'm not ruling out water in the sensor loom either but that crank sensor is one continuous shielded cable all the way to the ecu so I think it's unlikely.
The ignition system has coils mounted on the bulkhead with long ht leads to the engine, the leads are copper! (been copper for years). The plug boots have about 5kohm resistance and i run ngk Resistor plugs. My first thoughts are to change the leads for resistance type.
Anyway it's very strange and It's got me baffled, for now