2006 XC90 2.5T - couple things...

[bfry]

Mileage ~170k

Started car other morning - running very rough - CEL = P0300, P0304& P0305.

Started checking coils - 1&2 sparking fine - then and I don't know why I didn't finish checking the other coils, decided to do a compression test.

1-3 = 150
4 = 135
5 = 120

Go back out today to finish checking coils 3-5 and not getting a spark. Checked 1&2, which were good yesterday, but no spark this morning. What am I missing? Did I blow all the coils when doing the compression test because I didn't disconnect them?

Silly question, but plugs (all very corroded btw, picking up new ones right now) don't need to be in cylinder when doing a spark test right - not some kind of fail safe where computer detects no plugs so doesn't bother sending electricity to coils?

Thank you.

[bfry]

To check any coil - try disconnecting the injector rather than the coil itself www.youtube.com/watch?v=nDwtZCWU7u8

I think they are made by Bosch

You'll need to replace the spark plugs - when worn they cause the coils to fail

[bfry]

For coil pack, Bosch PN 0221604008 is the OEM version of the Volvo PN 30713416 at about 60% of the price.

[bfry]

Thanks for the reply’s above - so I picked up new plugs and new coil packs.

Turns over, sounds like it’s gonna start but no go.

Checked fuse to fuel pump - it’s fine.

Any thoughts?

[wanderdüne]

Check to see if you are getting fuel pressure at the rail. Use a rag to catch spray/excess fuel and depress the shrader valve on the fuel rail.

[bfry]

fuse 10 was blown - replaced and gtg - somehow musta blown when doing the compression test yesterday and would explain why no spark today. Running smooth now...

Thank you for the responses.

[bfry]

Fuse 10 in engine bay to be precise = ignition coils, ecm

[bfry]

Good fix! May look at the wires to the coils, sometimes the insulation may crack and touch the metal, or may get crushed under the black cover. Also good to look at the engine ground wire, I believe somewhere behind the top of the engine, close to the timing belt side