2004 volvo s60 2.4 stalling issue

[jonesg]

does it like the new sensor ?

[cichy1012]

does it like the new sensor ?

no code so it must be working but still problem. still confused about mass air flow sensor though. when car starts acting up i unplug it and it runs good, soon as i plug it in, it stalls.

[jonesg]

i'm not very versed on the maf but i think it goes into a closed loop when unplugged, the engine will run rich....but it will run.

maybe give it a spray with maf cleaner, dont get spray on the o ring.

[chrism]

When you unplug/replug the MAF sensor, is it presenting a fault code? You would think it would.

Also (playing catch-up to this thread) by “brake booster” I was referring to the big vacuum diaphragm unit between the master cylinder and the firewall. Those units can start leaking with age. Can you hear the auxiliary vacuum pump buzzing often?

[cichy1012]

When you unplug/replug the MAF sensor, is it presenting a fault code? You would think it would.

Also (playing catch-up to this thread) by “brake booster” I was referring to the big vacuum diaphragm unit between the master cylinder and the firewall. Those units can start leaking with age. Can you hear the auxiliary vacuum pump buzzing often?

no error code. no codes at all replaced the mass air flow and the car still stalls. when i drive around its fine. when i come to slow down the rpms start jumping up and down like 1000-2000 then boom the car dies. then i start it up and it drives.

swap out the throttle body maybe?
I dont hear any buzzing near the firewall. ill have to look more closely.

[jonesg]

the maf is a problem, your code reader , whatever it is , doesn't seem to be helping.
unplugging the maf will set a code if read with vida.

[cichy1012]

the maf is a problem, your code reader , whatever it is , doesn't seem to be helping.
unplugging the maf will set a code if read with vida.

I replaced the maf sensor. Have not unplugged it since replaced. Replaced based off previous comment about car running better when unplugged and stalling when plugged in.

[jonesg]

the maf is a problem, your code reader , whatever it is , doesn't seem to be helping.
unplugging the maf will set a code if read with vida.

I replaced the maf sensor. Have not unplugged it since replaced. Replaced based off previous comment about car running better when unplugged and stalling when plugged in.

genuine volvo part ?

[chrism]

You say the engine stumbles when you apply the brake pedal. If the car is sitting still and idling smoothly will applying the brake cause it to die or does it only die if you’re driving down the road and apply the brakes?

When it starts to stumble and you quickly release the brake pedal will the engine recover to a smooth idle or does it always die once it starts to stumble? Have you tried pinching shut the hose that provides vacuum to the brake booster?

[xHeart]

I am suspecting the air intake hose between MAF sensor and throttle body has developed a fine crack -- age, engine vibrations, failing mounts, material deterioration -- it will be hard to see without acting like a Hanes Men's Underwear quality officer.

A home-made diagnosis and remedy would be to apply a layer of JB Weld paste along the lip at each end of the pipe and joints, and let it cure overnight. I was successful with high-heat aluminum tape on our 1997 850 to get us home.