A vacuum fitting everyone should look at....

[Paul93Lotus]

I had this occur on my 1993 Esprit and thought it might be an isolated incident, but finding both of these vacuum elbows with serious cracks, this could be a source of many driveability issues and might be overlooked unless you actually pulled them off to examine.For me I am 3 for 3 as defective and cracked. On my SE the cracking allowed it to blow off under boost. On my S4s there is considerable oil residue around the fitting which leads me to believe it was venting to atmosphere.

On the SE version, I believe there is only one at the intake manifold. On S4,S4s, there is an additional one that hook into a tee. These are both related to the very small diamter plastic vacuum tubing that runs to the MAP sensor. They are rubber elbows that adapt the tiny plastic tubing to regular rubber vacuum line diameter. I have attached pictures for location as well as what my rubber vacuum elbows looked like

This is the little bastard.....

The manifold one can lead to inaccurate map sensor readings which will affect your fuel mixture.

This one tees into the vaccum pump/ebpv valve fittings....so this one could kill your vacuum pump if it leaks.

Edited October 16, 2007 by Paul93Lotus

[s4simon]

Interesting...

Although I currently have no issues, I shall check mine and report back later.

[DanR]

There's another one on the electric vacuum pump. Since replacing mine that pump is rarely working, indicative of no other leaks. I had also disabled the feed to the EBPV so it only operates the heater controls now.

[esprits4de]

Good point, I think if the vacc-pump is working frequently it is worth checking. If you rarely hear it, chances are there are no leaks....

[OwenGT3]

Hi,

Replaced these while I was fixing the squashed vacuum pump tubing. Mine were all cracked so replaced them with ones purchased from my local motor store, about

[Paula&Marcus]

Olaf,

As mentioned and outlined many times before .... the vacum pump system (either machanical or electrical) is ONLY operating the heater-controls and the EBPV and the throttle jacking capsule. NOTHING ELSE !

What can be seen on the pictures has NOTHING to do with the vacuum system !

It actually is the manifold pressure system (= MAP) which leads to he MAP-sensor and to the wastegate solenoid and to the c/coal-canister and ....

The Esprit is a Turbo car thats why it is different to other N/A cars !

If you look at the sticker inside your rear hatch you will see the all the routing of the hoses.

Cheers

Marcus

Good point, I think if the vacc-pump is working frequently it is worth checking. If you rarely hear it, chances are there are no leaks....

Edited October 17, 2007 by Paula&Marcus

[Vulcan Grey]

As mentioned and outlined many times before .... the vacum pump system (either mechanical or electrical) is ONLY operating the heater-controls and the EBPV and the throttle jacking capsule. NOTHING ELSE !

Cheers

Marcus

Marcus,

You forgot the brakes on the pre ABS cars... The 88-90 Esprits, use the vacuum to boost the brakes. Your first sign of a loss of vacuum will often be very hard and ineffective brakes.

When checking these "vacuum" lines also make sure to check the pressure line from the manifold to the one way valve and then to the fuel pressure regulator. This is all under the chargecooler on SE's-S4s & GT3's.

[Simon350S]

Mine are tossed on the vacuum chamber.......

Will need to replace them when I start rebuilding her....

Simon

[rocket63]

Checked mine a few months ago. All cracked. Will replace now I have the engine out.

[Paul C]

What can be seen on the pictures has NOTHING to do with the vacuum system !

It actually is the manifold pressure system (= MAP) ..

That would figure.

That very same little pipe came off on my car, the result was

it would not hold idle and stalled. Once connected back up it

was fine.

[Paul93Lotus]

What can be seen on the pictures has NOTHING to do with the vacuum system !

It actually is the manifold pressure system (= MAP) which leads to he MAP-sensor and to the wastegate solenoid and to the c/coal-canister and ....

Actually, the third picture is the one that does have to do with the vacuum system....that tee hooks into the vacuum pump, ebpv, and throttle jack.

[esprits4de]

Olaf,

As mentioned and outlined many times before .... the vacum pump system (either machanical or electrical) is ONLY operating the heater-controls and the EBPV and the throttle jacking capsule. NOTHING ELSE !

What can be seen on the pictures has NOTHING to do with the vacuum system !

It actually is the manifold pressure system (= MAP) which leads to he MAP-sensor and to the wastegate solenoid and to the c/coal-canister and ....

The Esprit is a Turbo car thats why it is different to other N/A cars !

If you look at the sticker inside your rear hatch you will see the all the routing of the hoses.

Cheers

Marcus

Yup,..., placed this on the board before my first cup of coffee!

Sorry, I was NOT THINKING.....

Then again this will be exactly what I will be looking at over the weekend, either my FPR or vac.system has a leak.....

See other thread about coughing....

cheers,

[Paul93Lotus]

Yet another culprit in the pillar where the map sensor is mounted near the fuel door, that's three for three cracked!

[lotusshaney]

Incase you need them there Advance/Retard elbows used on lots of older British cars. My motor factor sells them for 10p each !!!

[Riddlemr2]

Olaf,

As mentioned and outlined many times before .... the vacum pump system (either machanical or electrical) is ONLY operating the heater-controls and the EBPV and the throttle jacking capsule. NOTHING ELSE !

What can be seen on the pictures has NOTHING to do with the vacuum system !

It actually is the manifold pressure system (= MAP) which leads to he MAP-sensor and to the wastegate solenoid and to the c/coal-canister and ....

The Esprit is a Turbo car thats why it is different to other N/A cars !

If you look at the sticker inside your rear hatch you will see the all the routing of the hoses.

Cheers

Marcus

What might a Throttle Jacking Capsule be/do?

[Artie]

What might a Throttle Jacking Capsule be/do?

Accelerates the throttle on cold start to warm up the catalytic converter(if still equipped).

Artie

[DanR]

Works in conjunction with the exhaust backpressure valve to stop stalling while that valve blocks the exhaust pipe.

[Autocross7]

Not sure what cars other than K-Jet fuel system cars have a throttle jacking capsule... but...

The throttle jacking holds (or in my case "held" as I have disconnected it) the throttle open from cold start for the initial bit of time that the car needs to warm up. At the other end so to speak, the EBPV is closed - so the exhaust pipe is closed - for this period of time, so more throttle was required to run the motor to run. My car is running with 3 inch Tubi now and the EBPV has been removed - so as stated I disconnected thethrottle jacking. No need to run up to 3200ish RPM from a cold start!. It seems that the reason for this set up gets back to emmissions on start up or some non-sence (since from a cold start very few in the 80's cars would easily pass inspection anyway).

Drive topless!!!

Cameron

[esprits4de]

I got to second Paul on the urge of everyone looking at these items.

My Esprit is 94 MY, the two elbows are brittle on the outside, cracks all over. Funny enough they hold pressure, probably the cracks did not make it all the way yet....

I think it would be a good idea to generate a full list of "must" exchange rubber/plastic parts on these cars as they become more than 10 years of age...usual make'em breake'em age for rubber parts. As a spare part wholesaler I have the gudeline of a 7 year shelf life maximum for sale....so 10 years is actually already pushing it....

I will go through the parts list next weekend and see what I can come up with......