Red Turbo Esprit recommission project

[910Esprit]

That sounds pretty good to me for an LC 910  

[top-plumber]

8 hours ago, 910Esprit said:

That sounds pretty good to me for an LC 910  

The engine is rebuilt and everything is new so compression and consequently vacuum should be at optimum levels. 

[Andyww]

I finished fitting the pump but ran into an issue. The vacuum switch I used does not have enough hysterisis so when the pump reaches the set pressure the switch and relay starts chattering which is obviously not good. Maybe fitting some kind of restrictor in line to the switch might prevent this.

[top-plumber]

39 minutes ago, Andyww said:

I finished fitting the pump but ran into an issue. The vacuum switch I used does not have enough hysterisis so when the pump reaches the set pressure the switch and relay starts chattering which is obviously not good. Maybe fitting some kind of restrictor in line to the switch might prevent this.

I’m having the same problem. I think it’s a leak on my system as when I had the switch set at 25hg it wasn’t doing this. What’s your solution Andy?

smaller pipe work?

accumulator?

[Andyww]

I think the correct solution would be a switch with a bigger difference between on and off pressures. No idea where to get one with this spec. A restrictor in line with the switch might work, currently experimenting. 

I dont have a leak. What happens when you turn on from empty is the pump runs, then starts chattering like a machine gun when the pressure is reached as the switch is turning it off and on continually. Eventually it stops when the pump has been on enough time to reach past the switch on point. Is that what you have? Its a simple matter of no hysterisys (play) in the switch but maybe not that easy to cure.

[Andyww]

Well I tried a restriction in the switch line but no go. The fact is, the switch I am using is simply the wrong type. Its too precise. So I will have to do some more searching.

Edit: Found one and have ordered it. 

[Chillidoggy]

@top-plumber I don’t think your problem is anything to do with the switch hysteresis.

[top-plumber]

It’s definitely a Leak that’s causing the problem. I have just disconnected the servo pipe and blanked the end to leak test. When it comes upto vacuum it shuts of solid and holds. I even by passed the relay and same . The smallest leak is what’s causing the chatter. Maybe even the servo leaking. I’m convinced this is the problem. Leaking. I’m going to run a new pipe outside the car upto the servo and check again. If it’s the servo I will be able to tell immediately.if not then it may be a joint somewhere. Either way, I may just ditch the intake connection as the more joints the more chance of leaks. 

[Barrykearley]

Take a look at the elbow into the servo

[Chillidoggy]

51 minutes ago, top-plumber said:

It’s definitely a Leak that’s causing the problem. I have just disconnected the servo pipe and blanked the end to leak test. When it comes upto vacuum it shuts of solid and holds. I even by passed the relay and same . The smallest leak is what’s causing the chatter. Maybe even the servo leaking. I’m convinced this is the problem. Leaking. I’m going to run a new pipe outside the car upto the servo and check again. If it’s the servo I will be able to tell immediately.if not then it may be a joint somewhere. Either way, I may just ditch the intake connection as the more joints the more chance of leaks. 

Absolutely, you must cure any leaks first and see how you get on. For your application, that model of switch should work just fine. You might however want to think about its position in the vacuum system, as I suspect it could well be too close to the inlet manifold vacuum pulses which could upset it, and give the chattering you describe. If however you decide you want an alternative, higher specification vac switch then let me know.

[top-plumber]

1 hour ago, Chillidoggy said:

Absolutely, you must cure any leaks first and see how you get on. For your application, that model of switch should work just fine. You might however want to think about its position in the vacuum system, as I suspect it could well be too close to the inlet manifold vacuum pulses which could upset it, and give the chattering you describe. If however you decide you want an alternative, higher specification vac switch then let me know.

This is all without the engine running. I’m going to put another valve in behind the tee piece to stop any effect coming back from the inlet manifold into the vac pump manifold. 

Barry I have checked the servo elbow and it’s good. 

When the engine is running it should continually top up the vacuum leak at the servo and the pump will come on when demand is high.. that’s  my theory anyway. 

[pete]

2 hours ago, top-plumber said:

It’s definitely a Leak that’s causing the problem. I have just disconnected the servo pipe and blanked the end to leak test. When it comes upto vacuum it shuts of solid and holds. I even by passed the relay and same . The smallest leak is what’s causing the chatter. Maybe even the servo leaking. I’m convinced this is the problem. Leaking. I’m going to run a new pipe outside the car upto the servo and check again. If it’s the servo I will be able to tell immediately.if not then it may be a joint somewhere. Either way, I may just ditch the intake connection as the more joints the more chance of leaks. 

Plumber got a leak don't believe it👹

[top-plumber]

3 hours ago, pete said:

Plumber got a leak don't believe it👹

Anything constructive to say mate?

feel free...🤨

[Chillidoggy]

Don't remove the engine inlet vacuum connection whatever you do, unless it's solely for test purposes, that's your back-up in case the electric pump system fails. I seem to remember sending you a diagram which includes a check valve between the inlet and switch, is that in place?

[Sparky]

Wayne, have you used any kind of sealant on the unions?  Not RTV, naturally...

[Andyww]

This is how I connected mine. Thin lines are wiring, thick are hoses.

 

[top-plumber]

1 hour ago, Andyww said:

This is how I connected mine. Thin lines are wiring, thick are hoses.

 

I think we may need a nrv between the vac switch and the vac rail as this may have some effect on the switch when the rail is pulling vacuum? Direction facing the switch obviously. 

2 hours ago, Chillidoggy said:

Don't remove the engine inlet vacuum connection whatever you do, unless it's solely for test purposes, that's your back-up in case the electric pump system fails. I seem to remember sending you a diagram which includes a check valve between the inlet and switch, is that in place?

Yes but I think we need one after the tee piece protecting the switch from the rail vac? Maybe move the pump nrv to before the switch to achieve the same outcome?

[Chillidoggy]

20 minutes ago, top-plumber said:

I think we may need a nrv between the vac switch and the vac rail as this may have some effect on the switch when the rail is pulling vacuum? Direction facing the switch obviously. 

Yes but I think we need one after the tee piece protecting the switch from the rail vac? 

Have a look back at the diagram I sent you a while ago, there's one shown in-between the vacuum manifold and the T-piece. I was in Brentwood on Saturday, I could have swung by to take a look, which would have saved me from a Mother's Day experience.

Right, just had another look - there should be a non-return valve between the pump and the vacuum manifold. Otherwise, there's nothing to stop vacuum leaking out past the pump, because it doesn't have a non-return valve fitted inside it. Try that and let me know how you get on, but you still need to fix all the leaks, too!

[Andyww]

50 minutes ago, top-plumber said:

I think we may need a nrv between the vac switch and the vac rail as this may have some effect on the switch when the rail is pulling vacuum? Direction facing the switch obviously. 

Yes but I think we need one after the tee piece protecting the switch from the rail vac? Maybe move the pump nrv to before the switch to achieve the same outcome?

There already is one, in my diagram. The way shown is the only way it can go, and would be correct as the vac switch should react to the vacuum being held in the system regardless of whether it comes from the engine or pump.

I had another look at mine and when the vac reaches the switch point, the switch is so sensitive it reacts to vibrations so if you tap it, the pump pulses on then off. So it is also reacting from vibrations and air pulses from the pump and no doubt the engine, when its running. So I am hoping a switch which is intended for this specific application, which I have now ordered, wont do this.

[Chillidoggy]

Andy, I think there's two separate threads running here. My comments relate solely to Wayne's issue, which I've been working on with him from the start. I have no idea what you've done to your car, or what equipment you're using. Might be better if I bow out until it's resolved because it's clear to me things are getting confused.

[top-plumber]

5 hours ago, Chillidoggy said:

Have a look back at the diagram I sent you a while ago, there's one shown in-between the vacuum manifold and the T-piece. I was in Brentwood on Saturday, I could have swung by to take a look, which would have saved me from a Mother's Day experience.

Right, just had another look - there should be a non-return valve between the pump and the vacuum manifold. Otherwise, there's nothing to stop vacuum leaking out past the pump, because it doesn't have a non-return valve fitted inside it. Try that and let me know how you get on, but you still need to fix all the leaks, too!

That’s how I’m set up as your second description. How ever if I move the valve from behind the pump to infront of the switch it will have the same effect as we are looking for but it will stop any vacuum from the rail interfering with the switch inadvertently because the valve is now stopping any reverse pull. 

4 hours ago, Andyww said:

There already is one, in my diagram. The way shown is the only way it can go, and would be correct as the vac switch should react to the vacuum being held in the system regardless of whether it comes from the engine or pump.

I had another look at mine and when the vac reaches the switch point, the switch is so sensitive it reacts to vibrations so if you tap it, the pump pulses on then off. So it is also reacting from vibrations and air pulses from the pump and no doubt the engine, when its running. So I am hoping a switch which is intended for this specific application, which I have now ordered, wont do this.

Yes but where you have the valve behind the pump the rail can reverse pull on the switch. If you move the valve to behind the switch it will stop the rail reverse pull but still allow the pump to build vacuum. 

[Andyww]

4 hours ago, Chillidoggy said:

Andy, I think there's two separate threads running here. My comments relate solely to Wayne's issue, which I've been working on with him from the start. I have no idea what you've done to your car, or what equipment you're using. Might be better if I bow out until it's resolved because it's clear to me things are getting confused.

My apologies, I have hijacked Waynes thread a bit here, causing the confusion. I will not post any more about mine unless I get it working in which case I will create a new thread for my setup. 

[top-plumber]

The valve in this position allows the switch to be pulled in both directions 

On 03/03/2019 at 22:40, ChrisJ said:

@top-plumber - don't forget to keep this thread updated

 

@Andyww already here fella...

[top-plumber]

Ok. I have proved to myself on my car the chattering relay is definitely a leaking servo. When I remove the valve elbow and put a thumb on the end the vacuum builds immediately and shuts off the pump. If you take the relay out of the equation and just run a live through the switch you get the same outcome when pipe is connected to the servo, rapid pump fluctuations. I’m going to leave this alone for a while as when I get the engine running the vacuum rail may take up any vacuum that leaks away hence leaving the pump static until required. 

Question... does a servo have any vacuum pressure loss as a matter of course or should it hold pretty static over a given time period?

[Andyww]

7 minutes ago, top-plumber said:

does a servo have any vacuum pressure loss as a matter of course or should it hold pretty static over a given time period?

It should stay static. On mine once the pump has finished all its chattering which slows down to nothing, and vacuum is fully reached, the pump does not come back on at all if no braking done.