I have a 2000 volvo s40--it wasn't idling and you had to drive with your foot on the gas or it would stall-I thought maybe idle air valve but i took it in and they are saying the mass air flow sen

SOURCE: 01 s40 idle air control valve- hard to replace?

your IAC valve, idle air control valve is under the black plastic cover on the front right corner on the engine, remove cover undo valve, renew gasket and re install. ade 13 years volvo tech

SOURCE: replaced Idle Air Valve and EGR Valve. Car still runs rough.

There is an *awful lot* of stuff that can cause a car to have hesitation on acceleration.
Have a *good* mechanic read the codes from your vehicle and do the diagnosis.

You might also suspect a crappy or clogged EGR valve.

Like the other post said, you could try buying some MAF cleaner and carefully spray the element inside of the MAF sensor with it according to directions ... that's pretty easy to do. But this only works for the "hot wire" type of MAF sensor. The cold-wire or any other type this will not be possible for.

On the chance that the MAF is contributing to the problem ... here's something you might try.

MAF sensors are very very VERY sensative. Any, and I mean ANY crack or air infiltration in the duct or housing that goes from your MAF sensor to the plenum will cause your car to have problems.
(that is, the section of the air ducting that is *behind* the MAF sensor... in other words, the section of black plastic or rubber ducting that is between the MAF sensor housing and your engine.)

Disconnect the negative battery terminal.
Clean the whole outside of the housing, ducting etc with hot water and something to cut the grease a bit like dishsoap , maybe a couple squirts of carb cleaner and rinse - dry it off with a towel (make it pretty)... this means the whole outside of the rubber or plastic tube or duct between the MAF sensor and the plenum (air intake) on the engine. Then, check that every band-clamp (hose clamp) or any other fastener on that ducting is properly tight ... tighten any that are not. Now get a big roll of duct tape or electrical tape and wrap tape around any and all areas of that run of ducting that has any possibility of being loose or cracked including at any joints ... wrap it as if you were trying to stop a leak from a hose ... round-and-round.

Importantly, if any of the ducting is the hard rubber type that has a sort of "accordion" appearance, duct tape that section where those ridges are really well ... this is a notorious place for hairline cracks.

Finally, hook the battery back up and restart the car ... make sure to drive it for a good 20 or so minutes so that the engine can make any accomodations to it's electronic controls.

If this does not help and you decide to go back to spray your MAF sensor off, you will obviously have to unseal/untape at the joints necessary to access the MAF sensor. (But FIRST make sure you have the hot-wire style MAF that this will work on, eh?)

You may in fact end up taking your tape job back off if it turns out not to be the problem ... but hey it's a shot.

SOURCE: engine idles to low and stalls

Very similar problem, my car does not idle when i first start it. I have to keep my foot on the accelerator otherwise the RPM's drop to low and the motor stalls. I had a local Volvo dealer run a diagnostic (about $100 varies by shop). They said that it was the idle control valve motor.

The car has been robbed of the torque it once had and my MPG dropped from 28 to 21. You can find the part for around $170 on the web. The extra fuel costs were significantly higher than fixing the problem.

Prior to replacing this part I was able to manually adjust the trottle cable under the hood which helped with the car stalling. Be very careful when doing this, you can check your RPm gauge after making hte adjustment, I wouldn't adjust the throttle cable to the extent that the car idles over 1200 RPM, you'll still have to manually keep pressure on the accelerator for 2-3 minutes but after that the car should idle on it's own.

Hope this helps. Also, I love my volvo and there's nothing like a couple bottles of Octane Boost on top of a tank of premium. These motors are built for performance, try a high flow intake filter too, you'd be amazed how a few small changes like this dramatically improves the already great driving experience.

Have Fun, Joe.

Johnny Brown

• 5763 Answers
• Posted on Oct 10, 2009

SOURCE: I have a 2000 volvo 240 that idles and stalls.

before replacing any parts, check for vaccum leaks, volvo is pron for vaccum leak on left side of intake close to bottom of intake. also may have a bad o2 sensor. im surprised tech didnt give adefinate answer.good luck.

SOURCE: I HAVE A 1998 VOLVO V70 THAT KEEPS STALLING. TWO

I had a similar problem that stalling when slowing down to stop and removing the foot from accelerator pedal. This had been ongoing for almost 6 months. I have taken it to the big service companies who spent hours changing lambda sensors etc....After doing a bit of investiagtion seen that other owners of same car had the throttle valve cleaned (apparently this is required every 30K). I took it to our local one man garage. He reported that he fiddled around with throttle valve using solvent cleaner and general poke around for approx 10 minutes. Since then the car has worked perfectly and has not stalled since. RECOMMEND - MUST CHECK THROTTLE VALVE CLEANED.