Good to know. As for the age of my fuel filter, I do not know. I did crawl under and look at it some time ago, and it didn't seem like it had too much age. But that could just be because the car was kept super clean. It was owned by a retired service tech of the dealer I bought it from and maintained there from new, they even had few records to prove. So IF they followed the correct service schedule, I'd assume it was done. It didn't sit either as far as I know. 118k miles on it right now and I have put very close to 20k miles on it since I purchased it.mrbrian200 wrote: ↑Tue Mar 28, 2017 8:36 pmLooking at the plugs is a good start. I seem to recall experiencing some similar though not quite as severe symptoms on mine a year ago, and went down the same path (initially suspected a failed pressure damper but then determined there isn't one).
In my case with new plugs ran it ran slightly better but noticeably rough/uneven idle quality persisted. Couldn't trace to a specific cylinder I bought two new coils and switched them out with the originals 2 at a time to no avail.
Problem ended up being a combination of ring terminal grounds (grounds the coil packs primaries - the terminal wire crimps are prone to oil contamination if you have a leaky oil filler cap seal) and a couple wonky injectors that I suspect was due to contamination from POs neglecting to change the fuel filter. At 85k it was still had original filter, which should have been changed at least once by that mileage. Or from mostly sitting for about a year before I bought it. I have read somewhere Bosch gen 3s don't like that. One of the reconditioned injectors I got hold of was leaky and caused hard starting/long crank time/black puff of smoke at startup. The injectors I got were sold/listed for a GM 8cyl (same injectors) so with 3 spares in the box the leaker was off/replaced within a couple hours, and because it was switched quick for no additional $ I practically forgot about that.
Should you end up venturing down the reconditioned injector path there's a bit of roulette inherent to used injectors. I highly recommend acquiring more than you actually need. More often a set of 6 or 8 listed for some other make/model will be the same price or less than 5 listed specifically for your Volvo...because it seems the second you 'say' you own a Volvo the price goes up but mostly So long as the Bosch PN matches you're good. Bosch gen 3 injectors are a common upgrade on many older cars for people looking for better WOT performance and/or a finer atomized spray pattern/ improved fuel economy and emissions on vehicles originally equipped with Bosch gen 2's. I didn't beat up the seller over it for $70 or $80 I ended up with 5 perfectly good ones on the car + 2 spares out of 8 and was still happy.
My oil cap is a little leaky, I had the same problem when I had my 850 and it would fill all of the plug galleys between oil changes . This one gets a very very small amount of oil in it from the cap, so I'll pop the cover off tonight and take a look at the coils. Oddly enough, after getting home yesterday from a work and driving about an hour, mostly highway, I pulled the oil cap to see what it looked like in there. I did get a small amount of smoke for about 15 seconds, then it was fine. Pulled the dip stick and the same thing. Just a tiny puff. I know this can point to PCV which could cause starting issues, but I would think after being very warm and highway driven, a small amount is normal. I did idle for about 2 mins in my driveway too, and none of the hoses are hard, they're all like new, the ones I could reach anyway.
As for injectors, I would probably just go new with the Bosch on FCP. $50 each isn't too bad if I have to get them, just don't want to waste the money if I don't. I don't want to mess with refurb and have more issues. If it wasn't my daily and I didn't travel 300 miles a week, I would go with refurb. I simply drive too much and need reliability.