I've been trying to chase down an intermittant engine roughness on my 2006 V70 2.5T. Initially codes suggested ignition issues, but replacement of plugs/coils and fuel filter didn't resolve the problem. I'm uncertain of the best path forward and wanted to get y'all's advice before proceeding.

Engine is smooth for ~5 minutes after the first start of the day. When roughness begins it's present at idle, and most pronounced during acceleration. Roughness stops at about 3k RPM; I can avoid it by manually downshifting to keep RPM that high. There's a smell of gasoline when exiting after a bout of roughness; I haven't been able to localize its source.

Here are the codes that I pulled (link to PDF of the full reader dump)


Should I troubleshoot the Cyl 1 injector, or the pressure regulator, or is there something earlier in the fuel system that I should be thinking about?

Thank y'all for the help. I've read these forums for years and am happy to finally join in!

Everett

 

things to do: 1) test the fuel pressure to see the PSIs at idle and when you rev the engine 2) inspect the J tube in rear by the evap canister and see if there's any fuel leak/smell back there. 3) any signs of gas leaking out of the top of the tank? 4) test injector #1 for connectivity to make sure its not just dumping in fuel - does the plug on #1 look normal? Consider swapping out the injector and installing a new fuel pressure sensor but you may also have an issue with the fuel pump seal on the top of the tank.

 

Outstanding--thanks! I've renewed the fuel tank seal gaskets and verified fuel flow from the pump unit, but haven't checked pressure. Will do that and your other suggestions and report back!