Need some help with a vacuum hose connection

[AJ_Spider]

Hi all,

My Beta Spider has been off the road since last September, after having had some work carried out by a pro mechanic, looking at the fuel management and starting/stalling issues (it was reluctant to fire up after attempting to re-start after a run of about 20 miles, and it kept stalling when coming to a stop at red lights etc.). It seemed to be driving okay soon after the work had been done (plugs checked, carb repaired and fuel tank pressure was sorted among other issues), but I noticed when it was back in the garage (I have been working on the seat belts as they need to be replaced, but that's another story) that there was a leak underneath, since confirmed as coolant.

So off the road all winter while trying to find the source of the leak (the 'dash coolant low' light was showing all this time when the key was in ignition). I have topped it up with water for now to see if I can trace the leak, and the coolant light went off. However, when I have tried to start the car it will only crank and is very reluctant to fire again, and eventually I only get the red battery symbol on the dash, with the starter silent. I can go back the next day and it may start up after a few tries but I have to keep my foot touching the accelerator pedal to keep it turning over, otherwise it stalls. I think the starting issue is an electrical one, as the starter shows no signs of malfunction, like 'clicking' etc. and it will start-up after a few tries when using the engine start function on my battery charger (however with the same stalling issue when foot level accelerator).

On examining the hoses for the coolant leak, I also noticed that one thin hose was just hanging down (the mechanic never pointed this out to me, or forgot to re-attach after working on the carb or it just became unattached later?), so after a consultation with a friend a bit more mechanically-minded than myself, he concluded that this must be the vacuum hose and was contributing to the constant stalling of the engine. I have attached a photo I took yesterday with some labelling with what we think is the issue and the connection point where eat those should go. Would someone be able to confirm that this is correct, and if so what type of connector I will need?

Any suggestions gratefully received!

Cheers,

Andrew

[JohnFol]

Just taken a photo of mine and I have a vacuum pipe attached where you have an arrow saying "Should the hose. .  .."
On mine, the pipe you can see goes to a T-piece and one end connects to the bottom of the air filter box, the other to the vacuum advance.

That said, you say yours comes from "underneath the carb". Do you mean "carb" or "Air filter box"?

[AJ_Spider]

Hi John,

Thanks for replying so quickly and I've just been out to check and the pipe connects to that bolted connection directly below where the unconnected pipe is on the photo, which I assume is the air filter box? If this is the case, it seems like I am getting nearer to a solution with your advice.

Will the connector I need to source be threaded one end (to fit the hole in the vacuum advance, the diameter of which I'n unsure of)) and the other tapered to fit the end of the pipe (which has a 4mm internal diameter)?

Thanks again,

Andrew

[JohnFol]

Worth getting a few other comments as I hear some people block it off to improve running, others don't have a vacuum advance . . . .

[AJ_Spider]

Thanks John, I will keep checking in.

[peteracs]

Hi

As John says the connection on the carb is often blanked off. Originally it goes to the air filter housing situated above the carb. However the pipe you have shown in the photo does not look correct for that connection as it is normally a simple rubber hose as per the John’s photo. So….

Given you say it is connected at one end below the carb, it looks to me like one of the hoses connected to the inlet manifold. There should be either one or two hoses attached to this point, one goes to the brake servo via a one way valve, the other someone with a later car will have to confirm, but either way it should not be left open ended as this will negate the vacuum.

One quick question are your brakes working ok? If the vacuum is not being made to the brake servo they will take a huge effort to operate.

Hope this helps…….

Peter

[AJ_Spider]

Hi Peter,

Thanks for the information – so not what I thought then. As you mentioned it is coming off the inlet manifold, below the carb. I can't see where the open end should be fitted to comfortably, however (apart from that connection on the carb)? So I'll have to do a bit more delving, and hopefully someone with a later model like mine may be able to help and advise where it should go.

I didn't detect any problems with the brakes last time used last September, but take your point and it may have come loose since last used, so important to confirm I think.

Cheers,

Andrew

[JohnFol]

My 79 plate is at Peter described. Inlet manifold beneath carb has a 90 degree connecter to servo via valve...

[JohnFol]

This is the inlet manifold connection  that goes to brake servo.

[Neil-yaj396]

What is your loose pipe attached to at the other end?

[AJ_Spider]

Sorry, I've been away all weekend on a jolly!

The braided pipe in the foreground of the photo I attached is connected to the bolted attachment right below the unattached end in the photo, on the inlet manifold. The pipe is about 30cm in length and the logical place where the other end would connect to would be where I have indicated – I can't find any other place where it would go to comfortably, but as Peter pointed put, it should be a rubber hose, not a braided one?

In my Haynes manual, there is a photo on page 78 (Fig 6. of the petrol feed and return hoses, both of which are braided, and the return is of a similar diameter to the unconnected one on mine, so I'm just wondering if it is this, as I can't report that there were any issues with the brakes last time it was driven. Would this also indicate the reason why when I get the engine to start it will only keep running if I keep touching the accelerator pedal, otherwise it stalls quickly?

[JohnFol]

I think this is what you are describing. Braided hose, from inlet manifold, just beneath carb . . .
Other end should go to your brake servo via a 1-way valve

[peteracs]

Hi Andrew

To save us all getting too confused (I am at least), can you do a photo of where the pipe is actually attached to the inlet/carb etc?

Also what is the diameter in mm of the pipe. The fuel lines should be approx 8mm the vacuum is normally 12mm.

Thanks

Peter

[SanRemo78]

Don’t know if this’ll help (or hinder) but I have a carb/inlet manifold on the bench. To me the end fitting and overbraid screams fuel line. There are two feeds, inlet and outlet, pointing down from the top plate. Different internal diameters so you shouldn’t be able to assemble incorrectly. If the car runs it’s not the feed to the tank but maybe the return pipe? Trace the line back to the other end (air cleaner off to make that easier?)

[peteracs]

Hi

If it was a fuel line I would expect buckets of fuel to be coming out when the engine runs?

Peter

[SanRemo78]

Just noted the comment about a coolant leak. Is it the pipe that goes from the auto choke mechanism to the side of the inlet manifold? The leak  may not have been apparent when cold if there was no flow until the thermostat opened?
Guy

[AJ_Spider]

Hi all,

I've been doing some investigating this afternoon following all of your helpful suggestions. My conclusions are that the vacuum inlet line (from the intake manifold, just behind where I've marked the connection point of the braided line) is already connected to the servo unit – it is also a much wider diameter hose than the unconnected one in question (which has an internal diameter of 4mm John, so much narrower). So, Guy's answer that it is a return pipe seems to be the most likely explanation as to where the unconnected end fits, but I've not established where this is yet. The braiding is also looking a bit broken at the connection to the inlet manifold, so will probably need replacing soon as well. I've attached another photo for reference. I've already taken the air cleaner off, but would appreciate another pointer as to where the connection point for the return pipe would be.

I've also attached a photo of where the coolant leak seems to be coming from. I think it is at a joint rather than a hose fracture. As mentioned previously, I didn't experience any problems when out on the road i.e. overheating when engine was running, but only noticed the leaking when it was back in the garage laid up for some other cabin work.

Cheers again

[AJ_Spider]

Sorry, the first photo didn't attach, so here it is.

[peteracs]

Hi Andrew

Ok, the coolant leak photo shows the thermostat from what I can make out.

The mystery pipe is attached to the inlet manifold just a short distance from the servo take off vacuum line, so will be some sort of vacuum take off as well most likely, does your distributor have a vacuum adjust and does it have a hose going to it?

Lastly do I see the fuel lines being the old braided rubber hoses? (there most likely are two going to the carb, one from the mechanical fuel pump and one the return line going to the right hand front chassis rail, also one from the fuel pump to the same point on the right chassis rail). If so please get them all replaced as well as the ones coming from the tank fuel takeoff. The reason is simple, these old rubber hoses crack and leak fuel, especially now with the ethanol and you run the very real risk of a fire or a very strong smell of petrol at the very least. You need to use E9 rated hoses from a reputable manufacturer.

Peter

[AJ_Spider]

Hi Andrew

Ok, the coolant leak photo shows the thermostat from what I can make out.

The mystery pipe is attached to the inlet manifold just a short distance from the servo take off vacuum line, so will be some sort of vacuum take off as well most likely, does your distributor have a vacuum adjust and does it have a hose going to it?

Lastly do I see the fuel lines being the old braided rubber hoses? (there most likely are two going to the carb, one from the mechanical fuel pump and one the return line going to the right hand front chassis rail, also one from the fuel pump to the same point on the right chassis rail). If so please get them all replaced as well as the ones coming from the tank fuel takeoff. The reason is simple, these old rubber hoses crack and leak fuel, especially now with the ethanol and you run the very real risk of a fire or a very strong smell of petrol at the very least. You need to use E9 rated hoses from a reputable manufacturer.

Peter

Thanks Peter,

I'll look into the distributor query in the morning and check back in.

Andrew