Other XC90 Problem: Xc90 cranking but not starting

[Xc90Durham]

Xc90 cranking but not starting
So hear we go, I have a Volvo XC90 d5 on a 05,
My problem is she cranks but won’t fire unless jumped or booster pack, where she fires instantly. We have checked battery which is fine, auto electrition confirns nothing draining bat and that all is well on that side of things, the fule is coming through fine and have put clear pipe on from back to front to confirm no air getting in. Have changed crank, camshaft and fule pressur sensors. Have replaces high pressure fule pump and all 5 injectors, the starting motor is working as it shold . Soon as it’s jumped on a morning it will work all day starting and stopping, it’s the time it stands over night that something is happening that we can not figure out. It now has us completely beat.
I have maintained her to a high standard over the years and even though 230.000 on her she has functioned great. Has anyone ever come across this or have any suggestions

[paddy74]

Have you checked your glow plugs (I'm not sure if this is the correct name)? Sounds exactly like these to me.

If it starts with a power pack, they may get a little more power than from the battery and that is enough to start. Have you tried cranking it for for maybe 30 seconds to one minute? Does it fire up?

[mike19691969]

Sounds like you've changed everything but the battery.

My only reason for saying being that I have read numerous posts where the battery was to blame for all sorts of unexplained faults and weird behaviour.

Have you tried trickle charging the battery overnight then try to start with it? Strange that it works from battery during the day.

[Tannaton]

Where are you connecting the booster pack - direct to the battery or to a terminal elsewhere? I would check all connections from the boot to the bonnet...

Is the cranking speed any faster when using a booster?

[Xc90Durham]

Have tried boost on a few different points and all work, cranks allot faster with boost on. Have just tried fresh battery and glow plugs are glowing when put over bat

[Tannaton]

Originally Posted by Xc90Durham

Have tried boost on a few different points and all work, cranks allot faster with boost on.

That's your problem....

Likely corrosion in the connectors on the long lead that runs from the battery to under the bonnet or bad earth in the boot. A cold engine takes more cranking power than a warm one.

Two easy ways to diagnose:

- Crank the engine for 20 seconds or so and carefully feel all the connections to see if any are warm (caution - might get hot).

- Get a multimeter and using a long piece of electrical wire connect the +ve terminal directly to the +ve on the battery in the boot, connect the -ve terminal to the big lead on the starter motor/solenoid. Set range to 20v DC and crank the engine, if you get more than say 1.0v - 1.5v registering then you have a voltage drop on that lead. If so try connecting the -ve lead to the jump start terminal and repeat the test etc. to try and identify where the drop is occurring.

Hope the above makes sense?

[Xc90Durham]

Tannaton thanks for your Response. Unfortunately that’s th first thing tried befor sending it to n auto electrition