The strange symptom - B230F - V740

I've got strange symptom in my car. I don't know, it's normal or not. When I push the break pedal meny times (it's look like if I pumped by the breaks pedal),when car is stopped, I've observed that the free turns go from

700 RPM to 1500 RPM,...If I don't push the break pedal the free turns are 700 RPM, but only I push this pedal many tims in the moment, the free tuns go to the 1500 RPM.

Is it normal or not? I thnik maybe the breaks-servo id broke....

all the best....

Reply to
sq1euo
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I think the idle adjustment is too high, so the added amount of air the brake servo adds when you cycle it rapidly is beyond the range of the Idle Air Control valve to compensate for.

I recommend you check the vacuum hoses for leaks. If a leak is small enough the idle control can hide it under normal conditions. If not a vacuum leak, your idle probably needs adjustment.

The gurus can post the real way to adjust the idle, but I bet if you screw the knurled black thumbwheel at the bottom of the throttle body in about one turn the symptom will either disappear or be reduced. Do keep track of where it was set originally in case the new setting causes stalling.

Mike

Reply to
Michael Pardee

Could just be the non-return valve at the servo end or it's rubber seal. Worth checking this simple thing first before condemning the servo.

All the best, Peter.

700/900/90 Register Keeper, Volvo Owners Club (UK).
Reply to
Peter K L Milnes

U¿ytkownik "Peter K L Milnes" napisa³ w wiadomo¶ci news:dt5pho$jtf$ snipped-for-privacy@nwrdmz01.dmz.ncs.ea.ibs-infra.bt.com...

How can I check this??

Reply to
sq1euo

U¿ytkownik "Michael Pardee" napisa³ w wiadomo¶ci news:qaWdnSddieIx snipped-for-privacy@sedona.net...

If I good remember, I haven't Idle Air Control, because I've got LH 2.2 system,..and I set the free turn manual by knob.

Reply to
sq1euo

U¿ytkownik "sq1euo" napisa³ w wiadomo¶ci news:dt5m8o$l4a$ snipped-for-privacy@atlantis.news.tpi.pl...

I've observed the second symptoms,..whet I take the hall sensor for the hand and I've moved them, the hall sensor isn't stiff,but I can move it for all sides. It's normal or something is broken??

Reply to
sq1euo

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