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Matt, Engineer
Category: Volvo
Satisfied Customers: 21858
Experience:  Mechanical Engineer with 20 years experience in the auto industry, 8 yrs in formula 1 engine testing
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A couple days ago my Volvo xc90 wouldn't start. I eventually

Customer Question

A couple days ago my Volvo xc90 wouldn't start. I eventually got it to start and it ran for about two hours on the highway. Then it is wouldn't accelerate As I push my foot on the gas pedal but the funny thing was the car was still idling. So I pulled to the side of the road and the car won't start again it's been 3 days
JA: Has the vehicle turned into a gas hog? And how does it start -- same as usual?
Customer: Yes, it's a hot. But I can't get it started and when I do it is start and idle but as soon as I press on the gas but RPMs won't even rev
JA: What year is your XC90?
Customer: 2004
JA: Are you fixing your XC90 yourself? What have you tried so far?
Customer: Someone told me it could be the mass air flow sensor but I haven't tried it yet
JA: Anything else you want the mechanic to know before I connect you?
Customer: No
Submitted: 12 months ago.
Category: Volvo
Expert:  Matt replied 12 months ago.


I'd agree that the mass airflow is a possibility but I'd say this sounds like a lack of fuel and could be a lack of fuel pressure from the electrical pump at the tank.

1st thing to try is to remove the fuel filler cap and then flick the ignition on whilst listening for the brief ‘buzz’ of the pump

If the connections to the pump are corroded or damaged then the pump could stop at any time or could not be running at full speed. Check that its relay switches in and out and the relay contacts are clean and bright – replace the relay if in any doubt and do the same for the fuse,

Ideally measure the pressure at the injector rail (should usually be around 3Bar / 45psi +) and if this is low check the pump as described and also consider changing the fuel filter as if this partially blocked this too will reduce pressure.

You can also get this issue with contaminated fuel , if there’s water or dirt in the tank then either the petrol floats on top of the water or the filter sock on the pump is choked up – so if the other things check out then I’d consider pulling out the fuel pump and cleaning the filter sock

Expert:  Matt replied 12 months ago.

Ok I see that you've opened another question, its best to reply just on this one as you're charged per question

if the fuel pump fuses are burned then I'd replace them and use some contact cleaner spray on the fuse box sockets to clean things up

Expert:  Matt replied 12 months ago.


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