'04 XC Engine Misfiring-Further Updated (Moisture ruled out - possible defective coils, bad MAF) Topic is solved

Post by **jonesg** » 21 Jul 2020, 18:28

E Showell wrote: 21 Jul 2020, 15:50 Back from mechanic. Had him install new Volvo TB harness and new XeModex TB. Car is running like a top. Still don't really know what the problem was since it was cheaper to install both components at the same time, I could not do a truly scientific method single variable analysis.

Many dealership techs pigtail a new plug even if they don't replace the TB, just disconnecting it causes come backs.

Post by **abscate** » 21 Jul 2020, 19:27

Did you get old parts back? Would love to look them over

Post by **E Showell** » 21 Jul 2020, 19:39

He didn't disconnect the old harness, but I have the throttle body.

Post by **E Showell** » 22 Jul 2020, 13:47

Thanks to all who offered ideas, insight and suggestions throughout this saga. I appreciate all of the care and consideration.

Post by **- Pete -** » 22 Jul 2020, 20:41

Very glad to see you are back in business & glad it was a simple fix. Congratulations!

jamadams · Post by **jamadams** » 06 Aug 2020, 08:08

In my experience with Coil over Plugs, COP failure is caused by excessive plug gap. this can be the plug gap at the tip and also inside the plug at the built in resistor.
so, If your COP(s) fail, always replace the spark plugs. New COP(s) with worn/defective plugs are doomed to fail again.