Lancia Beta Forum

Technical stuff => Fuel System Carb => Topic started by: AJ_Spider on June 30, 2023, 12:03:25 PM



Title: Need some help with a vacuum hose connection
Post by: AJ_Spider on June 30, 2023, 12:03:25 PM
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


Title: Re: Need some help with a vacuum hose connection
Post by: JohnFol on June 30, 2023, 01:00:59 PM
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"?


Title: Re: Need some help with a vacuum hose connection
Post by: AJ_Spider on June 30, 2023, 02:06:55 PM
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


Title: Re: Need some help with a vacuum hose connection
Post by: JohnFol on June 30, 2023, 02:10:57 PM
Worth getting a few other comments as I hear some people block it off to improve running, others don't have a vacuum advance . . . .


Title: Re: Need some help with a vacuum hose connection
Post by: AJ_Spider on June 30, 2023, 02:18:23 PM
Thanks John, I will keep checking in.


Title: Re: Need some help with a vacuum hose connection
Post by: peteracs on June 30, 2023, 04:47:23 PM
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


Title: Re: Need some help with a vacuum hose connection
Post by: AJ_Spider on June 30, 2023, 05:06:31 PM
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


Title: Re: Need some help with a vacuum hose connection
Post by: JohnFol on June 30, 2023, 06:19:27 PM
My 79 plate is at Peter described. Inlet manifold beneath carb has a 90 degree connecter to servo via valve...


Title: Re: Need some help with a vacuum hose connection
Post by: JohnFol on June 30, 2023, 06:21:05 PM
This is the inlet manifold connection  that goes to brake servo.


Title: Re: Need some help with a vacuum hose connection
Post by: Neil-yaj396 on July 02, 2023, 11:15:01 AM
What is your loose pipe attached to at the other end?


Title: Re: Need some help with a vacuum hose connection
Post by: AJ_Spider on July 03, 2023, 10:48:04 AM
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 6.8) 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?


Title: Re: Need some help with a vacuum hose connection
Post by: JohnFol on July 03, 2023, 11:54:27 AM
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


Title: Re: Need some help with a vacuum hose connection
Post by: peteracs on July 03, 2023, 12:22:46 PM
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


Title: Re: Need some help with a vacuum hose connection
Post by: SanRemo78 on July 03, 2023, 12:25:54 PM
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?)


Title: Re: Need some help with a vacuum hose connection
Post by: peteracs on July 03, 2023, 12:28:37 PM
Hi

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

Peter


Title: Re: Need some help with a vacuum hose connection
Post by: SanRemo78 on July 03, 2023, 12:31:47 PM
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


Title: Re: Need some help with a vacuum hose connection
Post by: AJ_Spider on July 03, 2023, 04:01:33 PM
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


Title: Re: Need some help with a vacuum hose connection
Post by: AJ_Spider on July 03, 2023, 04:24:54 PM
Sorry, the first photo didn't attach, so here it is.


Title: Re: Need some help with a vacuum hose connection
Post by: peteracs on July 03, 2023, 06:06:03 PM
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


Title: Re: Need some help with a vacuum hose connection
Post by: AJ_Spider on July 03, 2023, 06:14:18 PM
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


Title: Re: Need some help with a vacuum hose connection
Post by: AJ_Spider on July 04, 2023, 12:22:25 PM
Hi Peter,

Yes, that is the thermostat in the coolant photo.

I have checked the distributor and it is a normal one without a vacuum advance. So I think we are back to square one in regard to the unattached pipe. Can we definitely rule out the possibility of attaching to the carb in the photo from my first post?

On checking the fuel lines they all seem to be in a reasonably good condition but I take your point and I will check them further in due course.

Andrew


Title: Re: Need some help with a vacuum hose connection
Post by: SanRemo78 on July 04, 2023, 01:21:56 PM
One daft question from me - are you still running the mechanical fuel pump? If the car has been converted to an electric pump the original may not have been removed. Should the pipe turn out to be a vacuum pipe and a potential cause of poor running I'd suggest blocking it to see if that makes any difference to the engine. Finally, a lack of start with only the battery warning light but no starter noises might indicate either a weak battery (charge fully or replace) or a poor earth from the battery to the earth point on the battery tray and/or poor earth from that point to the engine?

Keep at it, you'll get there!


Title: Re: Need some help with a vacuum hose connection
Post by: AJ_Spider on July 04, 2023, 06:16:01 PM
One daft question from me - are you still running the mechanical fuel pump? If the car has been converted to an electric pump the original may not have been removed. Should the pipe turn out to be a vacuum pipe and a potential cause of poor running I'd suggest blocking it to see if that makes any difference to the engine. Finally, a lack of start with only the battery warning light but no starter noises might indicate either a weak battery (charge fully or replace) or a poor earth from the battery to the earth point on the battery tray and/or poor earth from that point to the engine?

Keep at it, you'll get there!


I've checked and compared with the photo in my Haynes and it's the original mechanical fuel pump. Food for thought on blocking the vacuum pipe, if it is as such. Maybe I should give it a go, if it definitely doesn't go to the carb?

I did charge the battery a couple of weeks ago and although it started straight after, in the next few days it goes back to struggling to start as usual. Only when I use the engine start on my battery charger will the engine start up after a few goes (but obviously still the issue with it stalling after taking foot off accelerator pedal). So maybe there is a drain somewhere as well, but I've not been able to trace it yet? If there was an earth issue it was something I asked the pro mechanic to look at last year, and I don't re-call him having any concerns about this. But who knows? There seems to multiple issues going on, each one maybe affecting the next one along, so a bit despondent to be honest  :(


Title: Re: Need some help with a vacuum hose connection
Post by: peteracs on July 04, 2023, 07:19:18 PM
Hi Andrew

You showed the mystery pipe coming from the inlet manifold, so plugging it will only be a positive thing, give it a go.

As to battery, if it holds charge initially after a charge and starts the car, then disconnect it and leave for a period (24 hours?) and then reconnect and see if it still starts the same way. You can also use a multimeter to measure the volts at each occasion. If it does not start the same way then you have a poor battery. You may also look at the date on the battery to give you an idea how old it is. If the battery still starts the car as originally when just charged up, then you should look for a current leak, removing fuses in turn can often help, though direct connection to alternator can also be an issue. You just have to be methodical and patient……. This can be frustrating, but worth it in the end.

Peter


Title: Re: Need some help with a vacuum hose connection
Post by: AJ_Spider on July 05, 2023, 10:16:18 AM
Hi Andrew

You showed the mystery pipe coming from the inlet manifold, so plugging it will only be a positive thing, give it a go.

As to battery, if it holds charge initially after a charge and starts the car, then disconnect it and leave for a period (24 hours?) and then reconnect and see if it still starts the same way. You can also use a multimeter to measure the volts at each occasion. If it does not start the same way then you have a poor battery. You may also look at the date on the battery to give you an idea how old it is. If the battery still starts the car as originally when just charged up, then you should look for a current leak, removing fuses in turn can often help, though direct connection to alternator can also be an issue. You just have to be methodical and patient……. This can be frustrating, but worth it in the end.

Peter


Hi Peter,

Yes I will plug the vacuum pipe and see if there's an improvement!

The original battery was replaced with a Yuasa not long after I purchased the car (in May 2019), so in theory it should still be holding charge. I have noticed on testing with a multimeter recently that it has gone from 12.5 v after a charge to around 11.3 v weeks later, so something is definitely going on there as well. I have looked at removing fuses in turn in the past but not been able to locate a faulty one as yet. As you say it's a case of being methodical, so I'll give it another charge today and start from scratch with the plugged vacuum pipe and possible fuse issue see how it goes.

Thanks again for all your help with this and I'll report back soon.

Cheers,

Andrew


Title: Re: Need some help with a vacuum hose connection
Post by: JohnFol on July 05, 2023, 11:24:13 AM
Does this shed some light on it??

http://www.fiatspider.com/f15/viewtopic.php?t=28033 (http://www.fiatspider.com/f15/viewtopic.php?t=28033)



Title: Re: Need some help with a vacuum hose connection
Post by: AJ_Spider on July 06, 2023, 04:48:40 PM
I've put the air filter back on, charged the battery (it was about half charged on the battery charger scale before this) and plugged the pipe. This morning it started after a few ignition key turns, but unfortunately I'm still getting the stalling issue if I take my foot off the accelerator. After a few attempts when it does re-start after a few stalls it will then turn over but won't fire up, so no progress really. I can only conclude that the pipe was connected to something, as if it had been plugged in the past this would still be the case? Maybe if I keep the vacuum pipe plugged, the connection hole in the carb where I thought it should go in my first photo attachment should be plugged as well?

I'm going to check the battery with my multimeter next and report back.


Title: Re: Need some help with a vacuum hose connection
Post by: JohnFol on July 06, 2023, 04:55:47 PM
If you have auto-choke, press accelerator to floor twice before starting so choke is fully engaged.
Start engine as best you can. Put your finger over any hole or pipe that you think is a vacuum and see if there is suction. If so, just block pipe (for now). Get some carb cleaner and squirt it around gaskets, manifold etc. For example I found an increase in revs when squirting near inlet manifold, meaning I had an air leak. Squirt it in air intake and if revs increase then look at fuel supply / mixture


BTW where in the country are you?


Title: Re: Need some help with a vacuum hose connection
Post by: AJ_Spider on July 06, 2023, 07:57:00 PM
If you have auto-choke, press accelerator to floor twice before starting so choke is fully engaged.
Start engine as best you can. Put your finger over any hole or pipe that you think is a vacuum and see if there is suction. If so, just block pipe (for now). Get some carb cleaner and squirt it around gaskets, manifold etc. For example I found an increase in revs when squirting near inlet manifold, meaning I had an air leak. Squirt it in air intake and if revs increase then look at fuel supply / mixture


BTW where in the country are you?



Thanks, I'll give the auto-choke suggestion a go tomorrow.

I checked the battery with a multimeter and it was showing 12.45v consistently and also with lights turned on it was above 12v. To me this indicates that the battery is giving good charge or am I mistaken?

I'm also checking the distributor cap cable connections – I'm sure I labelled them correctly and marked the cap position the last time I took the cap off to check the condition of the distributor (which was like new), but just wondering if anyone has the sequence for cross checking, just in case I was an idiot when putting them back in?

John, I am over in Cardiff :)


Title: Re: Need some help with a vacuum hose connection
Post by: JohnFol on July 19, 2023, 04:27:53 PM
12.3v to 12v is a good sign (assuming the engine is off). Look for something higher than 14v when engine is running.



Title: Re: Need some help with a vacuum hose connection
Post by: AJ_Spider on July 19, 2023, 05:19:08 PM
12.3v to 12v is a good sign (assuming the engine is off). Look for something higher than 14v when engine is running.




I've had the battery disconnected all week and it's still showing around 12.35v on the multimeter. However I'm going to get a mobile auto electrician in tomorrow afternoon, to get to the bottom of this, as I'm not really making any headway. Wish me luck!


Title: Re: Need some help with a vacuum hose connection
Post by: AJ_Spider on July 21, 2023, 04:02:24 PM
Just a quick update. I had an auto electrician around yesterday and we started going through everything. I think we did find a place for that disconnected vacuum hose – it seems to fit nicely into a connection in the bottom of the air box, so that's where it is for now (I also cut a bit off the existing connection from the inlet manifold as it had fractured at the base). The battery was checked and was fully charged and in a good state, so that has been eliminated. The car did start up but we had the same issue with stalling after taking foot off the accelerator pedal. The spark plugs (which were new last year) were checked and they have sooted up and there was residual traces of petrol in their holes. Also the gaps hadn't been set properly in any of the plugs, they were too wide. Once gaps were re-set we were also struggling to get a spark when testing no. 1 plug.

I have lent him my Haynes manual and he is going to study the relevant electrical diagram and do some more research and come back next week when we'll give it another go.


Title: Re: Need some help with a vacuum hose connection
Post by: peteracs on July 21, 2023, 04:56:12 PM
Hi

This of course is a bit of a rabbit hole, once you start hard to know when to stop, but if over fuelling, it maybe the carb is flooding, has it had a refurb kit? Float can go bad and valve can leak, also assume return from carb to tank is connected and not blocked?

Poor spark on one plug may be bad lead, should be able to move leads around to check?

I assume the choke flaps are closed when engine cold?

Just my thought process.

Peter


Title: Re: Need some help with a vacuum hose connection
Post by: AJ_Spider on July 26, 2023, 04:14:49 PM
Hi

This of course is a bit of a rabbit hole, once you start hard to know when to stop, but if over fuelling, it maybe the carb is flooding, has it had a refurb kit? Float can go bad and valve can leak, also assume return from carb to tank is connected and not blocked?

Poor spark on one plug may be bad lead, should be able to move leads around to check?

I assume the choke flaps are closed when engine cold?

Just my thought process.

Peter



Hi Peter,

I take your point about it being a rabbit hole, but I thought to be methodical and check everything from battery through to ignition and beyond. The auto electrician is coming back at the end of the week and he's bringing some spark testing equipment, so we should know more after that, but I will ask him to check the leads as well. There does seem to be a collection of fuel underneath where the carb is, but I thought the mechanic who worked on it last year had addressed this, but maybe not well enough? I will check the choke flaps as well, thanks for pointing this out.

I'll report back once we've checked everything further.

Andrew


Title: Re: Need some help with a vacuum hose connection
Post by: peteracs on July 26, 2023, 05:03:28 PM
Hi

You do have to be methodical if you want to get to the bottom of it. I really meant you end up replacing loads of parts, some will be sensible/necessary others less so. This can amount to significant cost unfortunately.

Best of luck when your guy returns!

Peter


Title: Re: Need some help with a vacuum hose connection
Post by: AJ_Spider on August 02, 2023, 03:16:40 PM
Hi

You do have to be methodical if you want to get to the bottom of it. I really meant you end up replacing loads of parts, some will be sensible/necessary others less so. This can amount to significant cost unfortunately.

Best of luck when your guy returns!

Peter

Thanks Peter,

He is over tomorrow so fingers crossed we achieve something!

Yes, I'm shooting in the dark with some of the items I've recently purchased, but they can't do any harm I'm sure.

I will report back in due course.

Andrew


Title: Re: Need some help with a vacuum hose connection
Post by: JohnFol on August 05, 2023, 07:50:57 PM
I was down at BetaBoyz today and Mark had a manifold with the T piece on it.

If I remember correctly, it goes to a vacuum operated heating vent.

I'm sure someone will confirm or correct me...