Engine: 3.2: XC90 Misfire

[seandodwell]

Hi All,

I'm trying to get to the bottom of a misfire on Cylinder no. 6.

I have swapped plug, coil pack, and cleaned all injectors, and added a new one to no. 6.

Does anyone know if new injectors are plug and play or do they need coding in VIDA? I used FOMOCO ones matching the ext.

Any other ideas, fuel rail pressure is good, fuel pressure switch is good, new fuel filter fitted. My local garage drew a blank say I need to go to Volvo Main Dealer, earliest appointment is late April...HELP!!

Or anyone know mobile Volvo mechanic in west London??

2007 SE Sport 3.2 petrol

[Carlosos]

Are you getting a spark at the spark plug? Harness?

[seandodwell]

Yes all electrics check out, they did say they checked compression on 1-5 but could'nt check 6 as the spark plug was slightly threaded, so I've ordered a re-threader and compression tester will report back on that. Still want to know if injectors are plug and play or need coding?? Help>..!

[seandodwell]

Anyone do these injectors need coding once replaced? Thanks.

[ommony]

Did you ever manage to figure this out?
Mine has just developed a misfire on cylinder 6 as well. Haven't had a chance to dig into it properly or plug the laptop in to see what's going on, but in my case I know it's not injector-related as I have the same misfire on petrol or LPG. I've swapped coils/plugs quickly and didn't make any difference. Hoping and praying it's just something simple like damaged wiring and not a dead cylinder with low/no compression. I'm on 260k miles, so anything is possible.

[seandodwell]

Originally Posted by ommony

Did you ever manage to figure this out?
Mine has just developed a misfire on cylinder 6 as well. Haven't had a chance to dig into it properly or plug the laptop in to see what's going on, but in my case I know it's not injector-related as I have the same misfire on petrol or LPG. I've swapped coils/plugs quickly and didn't make any difference. Hoping and praying it's just something simple like damaged wiring and not a dead cylinder with low/no compression. I'm on 260k miles, so anything is possible.

ommony - sadly yes finally got a confirmed diagnosis. - Burnt valve, who knows the cause, but its head off and rebuild. Options were second hand engine (unknown beast) or scrap the car, it's 2007 SE Sport, but I love it and have done quite a bit to it, this is the first engine issue. I figure I can strip out the head myself, (a special Cam tool set required but readily available -£100), plus about £800 for a complete back to new head rebuild by a very helpful chap in Par Cornwall, I'm in London, but my brother lives near by. the gasket set is about another £150 plus consumables, the garage wanted £2.5k +, defo not in my budget. Since these 3.2's are getting rarer I think I'm going to do this and keep it.

I have two general questions for anyone who has an opinion.

1. Should I replace the timing chain & tensioners whilst I'm in there, &..

2. If I'm replacing the chain is it wise to replace the sprockets(Both cams inc. VVT and lower smaller drive unit sprocket (very expensive option!! about £800 extra for a full chain and sprocket set!!!).

3. Does anyone have any good recommendations for gasket sets for this little job!! & or Timing chains, Although I'd probably go original fro that if I change it.

Any comments welcome thank you.