cut off with air condition

[adri 2nr]

when a/c is on and car running hard andi gear down till second the idel level drops and the car cut offs...what can be the cause of this?

i figure it can be something to do with the timing

anyone know what can be the cause of this? ur input will be helpful

[~Vēġó~]

how's the idle when the car is at rest with a/c on????

[adri 2nr]

everything normal till a/c is on

[Hook]

I feel ur problem is the "step-up"....basically it's made up of an electrically actuated pressure switch and a diaphragm...there's usually two wires and two vacuum lines coming from the switch, one end is connected to ur intake manifold and the other line goes to the diaphragm...

the electrical trigger for the switch is connected to the a/c compressor clutch so that when a/c is off, the switch is closed, but when ur a/c comes on, the clutch pulls in and turns the compressor (robbing some engine power and dropping ur revs)

at the same time it activates the switch and opens the connection between the intake manifold and the diaphragm, causing the vacuum within the intake to pull the diaphragm....the pull if the diaphragm moves a lever which is positioned to barely touch the end of ur throttle valve so that it pushed (or pulled in some cases) the valve open a just little touch just to give u that extra 100rpm or so to run the system without causing the extra load of turning the compressor to make u r engine stall

ur problem can either be with the wires to the switch, the switch itself, the vacuum lines or the diaphragm....that's in order of easiest to check and find replacements

I suggest u take it to any reliable auto a/c ppl to get it fixed, but if u feel up to it u can check it and replace it urself

[adri 2nr]

thanks hook

[TurboDrive]

Hook you is ah real Scientist !!!

[Hook]

lol...nah saddis...I jus like to dig up and take tings apart

[fly]

which is more or less the same thing a scientist does...

[cheese pie]

^^^^^^TRUE

[X2]

Great info there.

Some cars, particularly newer ones can also have idle control valves that perform the same task, but bypass air around the TB. If your car has that setup and the valve sticks (in need of service) ... the cutoff will start happening.

[Xman]

Yuh know that show "gone in sixty seconds" when d big mortician man pretended to be dumb for the whole show...and in the end he belt out some vocabulary that would make ah librarian get wet........hook yuh like dat boy

[adri 2nr]

hook dropped the car by the mech today to check it out will keep u informed if ur right

[mini me AWD]

yuh doh need a mech to confirm that.

if is not that, yuh have ghost in yuh car meng.

[MISHI]

question...Doesn't the step up apply to carb cars generally? I think the ISC is supposed to handle that...

[Iceman]

Had a similar problem and it was a combination of the idle too low and a few vacuum lines dry rot. Hook have it right.