The Illusive "Bonus" Port

[Elanlover]

A bunch of years ago our beloved co-founder Doug made a recommendation to me. He suggested that I plumb the vacuum hose from my blowoff valve to the back of the plenum where a "bonus" port existed - one that was not in use, presumably capped or simply available to splice into. As it stands now my hose is spliced into the boost transducer like most other people's installations. I figured I'd get to it one day but with Doug having moved along I haven't a clue where this port might be.

Anyone have any ideas?????

[dapinky]

Yes thanks - it's where mine is plumbed in

[Enright]

Yeah, it's just next to the throttle body.

[dapinky]

Oh, alright then - I'll even show you where it is.....


(Blue arrow shows the rubber blanking plug/cover)

Vacuum Pipe.jpg

[Elanlover]

Thanks but you're going to have to better than that Dave (especially since you posted such a low res pic!)

What are the blue and red arrows and where is your valves plumbed into????

[dapinky]

Blair,

I suggest you visit your local opticians - there's nowt wrong with the pic size

But for a bit of clarity, I attach an old picture of the engine bay....

The blue arrows show the start and end points of the 3mm silicone vacuum hose (routed underneath the big inlet hose, and mainly out of view) between the dump valve and the inlet manifold.

In the previous pic, the red arrow just happens to have been on the pic I found already, and is for the heater vacuum, the blue one I added just for you to indicate where the 'extra' take-off is situated, but covered with a rubber 'cap'.

123.jpg

[Elanlover]

Well this is interesting. The first pic you posted appears to have 3 "ports" next to the sensor. 2 that are being used and the ne in the middle. On my car I have only 2 ports and both are being used. Strange................going in for another look.


And yes, my eyesight IS crappy now.

[dapinky]

Well this is interesting. The first pic you posted appears to have 3 "ports" next to the sensor. 2 that are being used and the ne in the middle. On my car I have only 2 ports and both are being used. Strange................going in for another look.


And yes, my eyesight IS crappy now.

Both the red and blue cars had the third port - and my spare engine also has the third port....

...perhaps yours doesn't have one (as it isn't used as standard) which is why you cant find it?????? Who knows with the 'parts bin' mentality as used?

[Elanlover]

Well, after sticking the boroscope back there for a good look I can definitely say that there's only 2 ports on my car. I had a good feel around back there and it seems like the ports are part of a "plate" that is mounted to the back of the plenum. I suspect that, since Lotus simply ordered engines from Isuzu (and didn't build them) that they either starting getting them without the superfluous port or they eliminated it as part of the modifications they made onsite. I split one of the hoses (possibly heater controls?) and spliced it into that one to clean up the bay a bit.

The good news is that my failing eyesight was NOT the reason for my inability to find it. Other "ports", yes. But not this one.

[GeoffSmith]

I've only got 2 - added lightness.