Secondary Throttle - Vacuum Take Off is Disconnected

[378S2]

Hello Team,

I have been poking about with my vacuum lines and found one to be split, which was an easy fix. But as I got more curious about what else might be showing signs of age, I found that the 'other end' of the secondary throttle vacuum take off was loose. Maybe I disturbed it when I did the last oil change, but I have not noticed any change in drivability since I have owned it so perhaps it has always been loose.

Questions are:

1. Does anyone have a good diagram of where it goes please? I do not have an endoscope so I will be reattaching it by feel.
2. Should I be excited that I am about to enjoy considerably more power?

Thanks very much
George

[378S2]

Update - I found some good photos on other threads, and I have now managed to get a hand to the point I think it needs to go. Haven't managed to reattach it though!

viewtopic.php?f=31&t=28409&p=364625&hilit=vacuum+leak#p364625

search.php?keywords=vacuum&t=19040&sf=msgonly

I am surprised that I haven't had any low speed running issues though, unless I just knocked it off but I don't think that's very likely. Given the secondary throttle is normally open, and closed when running at low speeds - I think my hopefulness that I am about to discover 20 free HP is misplaced!

If anyone has a top tip on how to reach the bloody thing to put it back on I’d be grateful!

Cheers
George

[378S2]

Ok all done - if anyone reads this because they have the same problem, the solution is to remove the header tank and disconnect the heater hoses from the engine side then move them out the way. Once all that stuff is out of the way you can reach in from the lotus position (kneeling at the left wheel) and reattach it.

I’ve scope creeped in to replacing all the coolant hoses now for the set of Samco hoses so I’ll have to let you know if I have 20 free horses once that’s all done.

[Aoki Magic Pants]

Ok all done - if anyone reads this because they have the same problem, the solution is to remove the header tank and disconnect the heater hoses from the engine side then move them out the way. Once all that stuff is out of the way you can reach in from the lotus position (kneeling at the left wheel) and reattach it.

I’ve scope creeped in to replacing all the coolant hoses now for the set of Samco hoses so I’ll have to let you know if I have 20 free horses once that’s all done.

Just to be clear, is it the pink hose that we're looking at here?

I'm getting idle flare on start up - it revs up to ~1500rpm before settling down a few seconds later & and a drop of boost when I hit full boost so I think I need to check the vacuum hoses for leaks.

[378S2]

Yes that's the one, it's covered pretty well in the WSM. I get both of those symptoms from time to time as well so maybe that's the problem.

If you run your engine and have a look in the middle of the intake inlets you'll see the secondary throttle actuator rod. When below the kick in point it should be down, and when the engine is off it should return up. So that'll help you confirm it is working.

My coolant system is still spread out over the garage so I cannot confirm it is working yet (very frustrating).

[Steve A]

I'm getting idle flare on start up - it revs up to ~1500rpm before settling down a few seconds later & and a drop of boost when I hit full boost so I think I need to check the vacuum hoses for leaks

I'm also getting these symptoms first start up of the day then much less so after that, seems like a common fault.
Is the this not accessible from below looking up ?

[378S2]

I think you would need to remove the starter motor. You’ll be able to tell if your line is disconnected by pulling it from the top. Once you disconnect a couple of cooling hoses to / from the heater and remove the hard line from under the oil separator it’s not so hard to reattach.