Vacuum 3

[RodJ]

I have 2 vacuum hoses running off the intake manifold.  The back one naturally suppliers vacuum to the brake booster, but the front 1 is a bit of a mystery as the light pop up is operated by electric. I have been chasing vacuum leaks. The hose looks like 3/8 then at the front of the bonnet there is a plastic pipe fitted into it with a hose clamp holding them together. What is the purpose of this hose. I have pinced the pipe off with a clamp and the lights still work. It has also slightly decreased idle revs. Thinking about disconecting and blanking off manifold port.

 

[exeterjeep]

I see you have an early Excel from other posts,

sounds similar to one of my previous early cars had the same sort of thing, the pipe at the front was only a few inches long and had a bolt in the end of it, so went no further. I just assumed that Lotus had not revised the intake area design/casting from what  used for the elite/eclat with the vacuum pods. Can't actually recall if this was my elite s2.2 (they had electric lights) or my 84 excel. I know that the elite s2 was said to have a development engine.

[drdoom]

On Esprit there are vacuum actuators for operating the flaps within the HVAC unit. Check your Service Parts Manual for that area.

Cheers

[soldave]

On 23/01/2023 at 16:29, drdoom said:

On Esprit there are vacuum actuators for operating the flaps within the HVAC unit. Check your Service Parts Manual for that area.

Cheers

Yup, I think it's that on the Elite and Eclat.

[jonwat]

Here's a diagram of the Esprit heater controls, it may give you an idea of what you're looking for 

[RodJ]

Thanks for your reply John, but my car is an Excel and are pretty sure heater controls are cable controlled. Will check again

[jonwat]

13 minutes ago, RodJ said:

my car is an Excel and are pretty sure heater controls are cable controlled. Will check again

As the Esprit & Excel were both in production together I'd be surprised if Lotus used two different systems, also Soldave in his post above states that the Elite & Eclat had vacuum operated controls.

[Escape]

The recirculation flap and face level vent flaps in the (early) Excel are vacuum operated, similar to the Esprit. It is clearly detailed in the manual.
On my RHD car the front vacuum line goes to a NRV just in front of the bonnet, from there the line goes inside the body over the LH wheel arch and into the dash area.

[RodJ]

On 05/02/2023 at 22:48, jonwat said:

As the Esprit & Excel were both in production together I'd be surprised if Lotus used two different systems, also Soldave in his post above states that the Elite & Eclat had vacuum operated controls.

John 

You are correct. Consulted my workshop manual and some flaps are activated by vacuum and one is activated by cable. Replaced a piece of vacuum hose that was previously just slipped over the end of the original plastic pipe with the correct size so cured the original problem of air leaking in.

Rod