240: stalling when pressing brake pedal

[volvo]

So, here's what happened this morning:
-got in, inserted key.
-cranked and started...idles very rough like it was just about to stall but did not.
-gave it just a little throttle, and it seemed to settle on a steady idle.
-pressed the brake pedal and pumped 3 times and car stalled.


My wife told me that yesterday the car stalled on her 3 times, each time right after pressing the brake pedal.


What could this be?
Do I need a new brake booster or that little white valve that's on the booster with a hose attached to it?


The plugs, cap, rotor have about 10,000 miles.

[TrickMick]

pull the vac line at the manifold and plug the nipple on the manifold....
does it die the same way??
if NO....carefully remove the "valve" from the booster and apply vacuum to
"booster side" of valve (it's a ONE WAY VALVE..if it passes vac *(BOTH
WAYS* it's due for retirement)

connect the vac line back to the manifold...partner in crime starts engine whilst
YOU hold thumb over valve opening - modulate thumb (listen for HISS indicating
valve is allowing "vacuum" to pass can you make the engine die as noted??

while yer out there under the bonnet *LISTEN* for the tell tale HISSSSS of a
vacuum leak....I stuff a small diameter 3 foot length of hose NEAR my ear
and wave it about poking at injectors bases / accordian hose to Throttle Body
Idle Air Control motor / Flametrap / etc....wave it over the BOOSTER CAN
and listen for a CONSTANT HISS (the booster will reach it's "low pressure state"
fairly quickly) - if it has a CONSTANT HISS the diaphragm is faulty (sometimes you
can eve hear the "hisss" INSIDE THE CABIN (under the dash near the brake pedal
"rod" that goes into the booster / master cylinder)

the "stalling / dying" may be related to brake boost use *OR* it may just be the "straw
that broke the camels back" and there is ANOTHER VAC LEAK you need to address...

booster valve is *$ALTY* at $25 USFRN:
http://www.fcpgroton.com/product-exe...category_id/45
this is one part I get irritated when I have to replace --- it's freakin PLASTIC dammit!

[volvo]

Originally Posted by TrickMick

pull the vac line at the manifold and plug the nipple on the manifold....
does it die the same way??

The vac line that comes out of the plastic valve on the booster, correct?

[TrickMick]

Originally Posted by volvo

The vac line that comes out of the plastic valve on the booster, correct?

* YES *

[volvo]

ok...i'm going to look into soon then, and will report back.

[volvo]

So things seem to be repaired and all good.

I removed the booster check valve and blew into it and drew air from it and it definately allowing air flow one way...from the booster to the manifold. I hooked everything up again and started the car...it idled very inconsistently and i had to open the throttle just slightly to keep it smooth.

Then I looked at the ISV. I tapped it with my screwdriver handle and it idled smooth again. I went and pulled the ISV and cleaned it out...all the stores were closed and all i had was seafoam and carb cleaner so I dribbled a little seafoam into the ISV and let it all drain out. cleaned both in and out tubes on it, reinstalled and it idled like a dream. went for a test drive and pulled over a few times to shut it down and restart the car...no issues. pumped the hell out of the brake pedal...no issues.

im guessing the ISV just needed a cleaning? will the seafoam cause problems in the future?

For peace of mind i may get another ISV and put it in there amd the xar will stay ok for a day or two until i get the new.

[TrickMick]

Originally Posted by volvo

So things seem to be repaired and all good.
I removed the booster check valve and blew into it and drew air from it and it definately allowing air flow one way...from the booster to the manifold. I hooked everything up again and started the car...it idled very inconsistently and i had to open the throttle just slightly to keep it smooth.
Then I looked at the ISV. I tapped it with my screwdriver handle and it idled smooth again. I went and pulled the ISV and cleaned it out...all the stores were closed and all i had was seafoam and carb cleaner so I dribbled a little seafoam into the ISV and let it all drain out. cleaned both in and out tubes on it, reinstalled and it idled like a dream. went for a test drive and pulled over a few times to shut it down and restart the car...no issues. pumped the hell out of the brake pedal...no issues
im guessing the ISV just needed a cleaning? will the seafoam cause problems in the future
For peace of mind i may get another ISV and put it in there amd the xar will stay ok for a day or two until i get the new.

*Idle Air Control* Motor...wil live to fight another day as long as you
didn't cook the insulation off the motor itself....I've had to replace
TWO of them since Moby Dick was a guppy...you'll be fine...
save yer do$h for other bits (a j/y part will suffice if you feel the need)...
clean it w/the "Mass Air Flow" stuff (working to keep the liquid out of
the motor part) and then pack yer "freshened up" part in a bag w/a
bit of the "rust proofing paper" that lots of things come with these days
(it's the brown sheet that you "wonder whutinell is THIS")

http://shop.advanceautoparts.com/web..._T|GRP2030C___

GOOD JOB (looking elsewhere *and* FIXING IT!)