Inlet manifold pressure - advise please

MikeS

On idle my MAP sits around 26 KPA but if i press on the brake pedal quickly the KPA rises to 30 and the throttle position drops from 5.8% to 2.4%,

AM i right in thinking the vacuum servo hose pumps air into Inlet manifold when i press on the brakes ?, bit it wont suck air from the brake servo due to the one way valve

also when the throttle position is at 100% 😛 the KPA in the inlet manifold also reaches around 96 - 98 KPA but wont reach 100

about time some one gave me some info and advise on this forum

I already scared Daz off on msn 😛

JohnnyN

Vocky is your man for this. Neil carried out some research on this IIRC??

sdbutler10

What you need to know this for then mike??

vocky

the servo works on vacuum, so when you press the brakes you increase the pressure inside the servo pipe, this is most likely why the pressure in the inlet changes dunno..

markv

MikeS said:

also when the throttle position is at 100% 😛 the KPA in the inlet manifold also reaches around 96 - 98 KPA but wont reach 100

Don't know what setup you have, but we've seen that happen on all engines with the 2.4 manifold. Guessing at the moment there is a flow restriction,
might be the throttle valve, but not sure..

Mark

MikeS

new 2.2 manifold with blanked off egr pipe

piper manifold
2.5" downpipe 200 cell sports cat
magnex cat back
egr cheater
ported throttle body
k&n panel filter