Hello I have a really standard carbureretor PICT 34 but it seems to have something weird on the front (or back end of bus) as the engine is a t1 1600 from Brazil. I haven't posted a piccie of it as I haven't got a photo bucket account but I took one of it with my phone. Basically it seems to be some sort of idle compensator/ suppressor thingy with a pipe on it that sucks in air. What it does is delay the throttle cable from hitting the choke step thingy for a couple of seconds once you take your foot off the accelerator. I took the vacuum pipe off and it cures the slight over reving that happens as a result of taking your foot off. But the device still sucks in air. Does anyone have a clue what I'm talking about coz I don't think I've explained myself very well! What I want to know is A, what is it and what is it for. B, is it easily removed/by passed? I know not having a picture isn't helpful. Just hoped someone might know what I'm on about if they'd seen it before. P.
Sounds like a throttle damper If you use the tapatalk app you can upload the pic direct from your phone
Ta very mooch. Is a throttle damper to stop it snapping back too fast/hard. If so mine is damping it too much. Coz when I take my foot off the pedal i sound like Trevor the revver for a couple of seconds.
Does look like a throttle damper. Never seen a vac operated one before - they're usually a springy affair - but if it's a Brazzy bus... You can take it off if it offends you. It's there for emissions purposes to stop the slight puff of over-rich mixture when you take your foot off the throttle. Bung the vacuum pipe up.
Brilliant. Thanks for identifying it and the advice. Makes a lot of sense. Brazilian engine, German bus. Not really sure where the other end goes. I'll have a look tho. Thanks again to all.
I think some 70s US busses had similar. Take your foot off the accelerator, and it would take two seconds for the revs to die down...
My van had one but it was a pressed steel casing and had no vacuum connection. I threw it over a hedge
Good thinking. My Solex had one - I think the damper diaphragm goes after a while, and they just sit there doing nothing. It went over the fence...
I think mine is going to hit some suitable vegetation sometime soon. I just plug the two ends where it had been connected?
Take the whole lot off and plug any vacuum connection to the carb, otherwise it’ll upset your mixture.
Manifold vacuum dump..should only operate at high depression ie sudden release of throttle. Um part of emission control set up....don't remember anymore...
