Hi

When I drive the engine can sometimes suddenly cut off ( I think it cuts off but it might be another reason for the sudden stop) and when I release the gas pedal and gives gas again it runs again. This seems to happen more often when I drive under more heavy load uphill or when I have a trailer behind the car. I can also drive for many miles without that this happens. The cut off is not as I have tested by turning off the ignition key during driving it is more sudden than that, it feels as if the whole car stops for a milli second. So have started to believe that it might have something to do with the valve between the manifold and the brake servo because sometimes when I brake something under the hood will sceem like a pig and as teflon tom mentioned if this valve is not working ok it can increase idle speed which I have noticed sometimes as well. Can it be possible that the valve suddenly opens by itself ( if it is broken) and the vaccum from the manifold activates the brakeservo and the brakes for a millisecond which causes the sudden stop. Should I notice that the brakepedal would go down to the " floor" in this case or can the brake servo move against the main brake cylinder without moving the brake pedal. I do not know if they are linked togather or if they are free from each other?

I know that others have described the same problem but I have not yet find an sucessful answer to this problem.

Regards

Svisse16

I do not think the servo works the way you seem to think it does.

AIUI the servo acts to multiply the force you're applying to the brake pedal, so unless the pedal is moving down for some other reason then the vacumn level is irrelevant.

Yeah, the servo just multiplies the force you're putting into the brakes, it doesn't do anything like you've said. While the valve or hose may be broken, they wouldn't apply the brakes.

the valve between the manifold and brake servo is just a non-return valve, they can cause an increased idle speed if they are broken yes,

the running issues you have are more likely to be throttle body related tbh

Hi

Thanks for answers from all of you. I will check the throttle and buy a new hose and valve( it is one spare part cost 60 Euro) between inlet manifold and brake servo so I hopefully will get rid of the noise from "the screeming pig under the hood" when I brake.

Regards

Svisse16