- Joined
- Jul 2, 2007
- Messages
- 5,294
Changed out the plugs on my Forester last month or so, used the factory type NGK FR5AP-11. Service manual says gap to be between 0.39 - 0.43, they showed 0.44 out of the box so I set them to 0.41. After several weeks of the idle dropping almost to stall upon downshift clutch engagement (manual trans) and actually worse fuel economy than before, I finally had the epiphany to perform the idle re-learn procedure recommended on some subaru forums, since I had removed the battery to get to the driver side plugs. Well, I can tell you that the procedure is for real because it solved the momentary idle dropouts on down shift and fuel economy returned to normal. But, the idle is still lumpier than before. Before, there was very little if any shake, now there persists some shake that wasn't there and I can hear a random miss at the exhaust tips that clears up once some rpm's are added.
Does this sound like ignition wires? I had to tug like [censored] to get the boots off the plugs, they hadn't been touched since the factory put them on in 2008. They're those deep reach type about 6" long and stretched a lot as I pulled them off. The wires are Packard which is usually carbon core. I'm wondering if the boots stretching during removal upset the conductive material enough to cause the random idle chuggle.
Probably replace the wires, yes? Coil (waste spark type) is fairly new only about 7000 miles (failed and threw misfire codes, replaced no charge by Subaru under a TSB).
Does this sound like ignition wires? I had to tug like [censored] to get the boots off the plugs, they hadn't been touched since the factory put them on in 2008. They're those deep reach type about 6" long and stretched a lot as I pulled them off. The wires are Packard which is usually carbon core. I'm wondering if the boots stretching during removal upset the conductive material enough to cause the random idle chuggle.
Probably replace the wires, yes? Coil (waste spark type) is fairly new only about 7000 miles (failed and threw misfire codes, replaced no charge by Subaru under a TSB).