I have a '97 mark with 120k and an engine misfire that I've been chasing for 6+ months. The biggest problem is no misfire codes for this last bout. I replaced 2 coils a few years ago (Autozone coils) and had codes then, then I replaced all 8 coils with Summit coils -they talked me out of buying Accel coils stating they had a high failure rate. Since then I have reinstalled one of the Autozone coils I saved when the first Summit coil failed. I noticed all of Summits were cracking around the flat pad on the bottom, the stock and Autozone coils never cracked. I put liquid elect. tape on the cracks hoping to delay the inevitable. Now with no misfire codes I'm swapping the other Autozone coil around trying to find the miss.
Recent work -fuel filter, seafoamed 2x, then sparkplugs, cleaned and inspected the boots inside and out (no cracks) and shrinktubed them from the mid-lip down. Then with eng. running unplugged and removed each coil, attached it onto a ground-wired sparkplug and plugged it in again to watch the spark (I should have bought an adj. spark tester) on all 8 coils. I took my best guess based on color and put the other Autozone coil in. THIS test thru no misfire codes! With 6 cracked Summit coils to change out it would be nice to do them one at a time as they fail but it's a total pain when the car isn't sayng which one anymore.
I have changed no eng. sensors since I bought the car 11/03 with 52k on it.
The car ran right for one day (each) when I did the plugs, the boot clean up and the last coil change.
My manual mentions "Failure Mode Effects Management" portion of the PCM can allow the emg. to run with a bad CKP or CMP (crank or cam sensors).
Which sensor would cause no misfire codes? I'm thinking the CKP sensor.
Recent work -fuel filter, seafoamed 2x, then sparkplugs, cleaned and inspected the boots inside and out (no cracks) and shrinktubed them from the mid-lip down. Then with eng. running unplugged and removed each coil, attached it onto a ground-wired sparkplug and plugged it in again to watch the spark (I should have bought an adj. spark tester) on all 8 coils. I took my best guess based on color and put the other Autozone coil in. THIS test thru no misfire codes! With 6 cracked Summit coils to change out it would be nice to do them one at a time as they fail but it's a total pain when the car isn't sayng which one anymore.
I have changed no eng. sensors since I bought the car 11/03 with 52k on it.
The car ran right for one day (each) when I did the plugs, the boot clean up and the last coil change.
My manual mentions "Failure Mode Effects Management" portion of the PCM can allow the emg. to run with a bad CKP or CMP (crank or cam sensors).
Which sensor would cause no misfire codes? I'm thinking the CKP sensor.
