Trying to help a friend diagnose a problem with an XC90 (was my car until 6 months ago). My friend went to start the car a few days ago but it wouldn't fire up. Turn the key and it'll crank strongly for approx 5 seconds then stops cranking (even with the key still turned on). Feels like the ECU is saying hmmm I've tried long enough now I'm shutting everything down. Current owner called AAA who thought it was a dead fuel pump (he stuck a tube/stethoscope into the gas tank, cranked the engine, but could hear no swirling fuel or noise from the pump. Something makes me think this is more likely an ignition problem than a fuel issue... but I'm not sure how to narrow it down. Does anyone have thoughts on what the cause might be or suggest steps to troubleshoot it?
What I've done so far:
- Used my OBD2 diagnostic tool (OBDWiz) to see if there are any error codes... surprisingly there are none (sadly I don't have a VIDA/Dice)
- Ripped out the back seats/carpets and fitted a spare PEM (fuel pump control module) that I had... no change, engine still won't fire into life
- Fuel pump fuses OK
- General inspection of the wiring in the engine bay... all looks good visually.
- The battery is good and cranks solidly (it was a new battery fitted 5 months ago)
Tomorrow I'll pull a spark plug and see if there is spark (and if there's any fuel getting to the cylinder).
Could be a crank or camshaft position sensor, but I'd have thought that would have shown up as some obscure error code on the OBDWiz... the only way I can think of diagnosing is throwing money at it by fitting new sensors.
Or we bite the bullet and throw $300+ and buy a new fuel pump in the hope that's actually the cause.