P2 Can someone tell me what this part is? 31400692

[abscate]

This part on my car looks broken. There was a spring in side and it fell out. I dont know what the replacement part is.

Come round to the Albany Volvo club sometime! I spend most mid week up in Bethlehem , just South of the city help fixing stuff.

[Goldchemist]

I am having rough idle and reduced engine performance issues. Initially had MAF codes. (replaced the MAF with a new Bosch but that did not help) I noticed it runs better in the warm months. I checked all air intake, hoses etc for vacuum leaks. It sounds like my brake booster vacuum pump I always running, well, on and off but always going on and off. For example, after I start it, the vacuum pump runs, then shuts off, then runs again, then off for a minute or two, then on, like it's constantly trying to keep the pressure. Sounds like an obvious leak somewhere. I would like to try to test the brake booster vacuum switch. br0dy519: What does it mean to 'jump out the two terminals on the wire pigtail'? I think that means to connect a positive and negative to the two terminals to an electrical source. Can I use the car battery itself? Also, does it sound like that little switch could be causing all of these drivability issues? rough idle etc. Thank you!

[abscate]

If that switch flies apart it puts a vacuum leak onto the motor which will cause poor running.

[Goldchemist]

If it flies apart? I've seen some examples of these that are cracked and broken apart but mine is perfectly intact, do they fail as in stop opening and closing? I'm setting up a good test of the switch tomorrow after work to confirm if it is opening and closing. I see a post from you earlier in the thread about fixing this ASAP if the pump is running all the time. I figure that is what mine is doing, the pump keeps turning on and off, replacing it ASAP. thank you.

[abscate]

They can fail lots of ways. Just noticed you are LI , I’m in Port Jeff area

[br0dy519]

Don’t feed voltage there. The switch is a volt free dry normally open contact. Unplug the connector to the switch and use a wire or paperclip to jump it, and it will send the signal to enable the pump and you shall hear it run.

[Goldchemist]

I see now. oh man I'm like a mad scientist out there. totally messing things up but learning a lot in the process. While trying to take the brake booster vacuum switch out I broke the top off and it 'flew apart'...lol. now I see how it all works. Ordered a new one from FCP Euro. Don't feed voltage there? too late, it was like the 4th of July under my hood. When I did unplug the switch the pump shut right off. Plugged back in, pump switched on. I can confirm a few things: 1. my vacuum pump is running too much. 2. my car is running very rough. sometimes goes into limp mode. 3. everything started with a MAF code P0101. 4. Now I'm getting other codes also.

Waiting for my new switch to arrive. Thanks for all the help.

Yes, I'm in Islip. I am a Petty Officer 3rd Class in sea of estrogen. I have 3 daughters plus 1 grand daughter.