Herald Stromberg 150

[karl1]

Hi all!

I have a Herald 1965 1200 with the horrible Solex carb.

When I got this car the car had the electronic ignition fitted to it.

So this is the story.  

Car when brought was not running due to a fuel leak ( float problem ).

Car would run but had very poor idle and pick up ( Just on take off).

So I manage to find a new for old solex carb which made no difference to the runing what so ever! 😲


I then read about fitting a single Stromberg CD 150 carb to the car.

I was unable to find an inlet manifold but found a home made jobbie that was told worked fine ( 🤔 )

With a lot of messing around I sorted of fitted but having to leave to mainfold bolts off.

I have only at this time found how to wire up the choke cable. The throttle is going to be another story!!!!

NOW!!!! It runs on the choke when fully open but dies if I try to shut off the choke even when hot.

I have noticed a lot of black soot on the wall from the exhaust (Rich  of course as im on choke) !

I have been around with the good old break cleaner for vacuum leaks and all seems well.

So short of beating it with a hammer im at a loss?

Oh yes I have checked the timing!!!!

I thought old cars were simple ie air/ fuel / timing????

[poppyman]

Hi Karl,
First of all i would ditch the stromberg
Get the solex stripped and clean out all the jets and passages with an airline.
Then fit it back on making sure the accelerater pump jet is working. It is unlikely that two carbs will give the same problem.
Cheers,
Tony.  

[karl1]

Moring Tony and thanks for your reply.

Well I have had two Solex  carbs and the second was a New old stock and yes both were cleaned and new parts fitted to the first carb.

I have read that members dont like the Solex and like the Stromberg conversion ? 🤔  

I went out there again to try the car, it starts fine on the choke and will rev using the throttle leaver ( As I dont have a cable fitted as yet ?

Then sort of fades the comes back to life etc.

Im wondering if it could be the fuel pump????

[poppyman]

It is possible, try reving the car until it stops.  Then check if you have fuel in the carb......
If not sounds like pump? Have you checked if the pump is full of crap? and any fuel filters if fitted? Also was it running ok prior to this? Or have you just got the car?

Cheers,
Tony.  

[karl1]

I have only just got the car say maybe 2 or 3 months ago but as said had problems from the start with the Solex carbs.

I have opened the top of the fuel pump and there was no filter in it ( unless I have to open the lower part of it?)  

If I use the throttle on the carb it wont die not with the choke open.

What happens is then after 15 seconds or so the revs begin to fade and just as you think it will cut out it revs back into life again 🤔

So am I right in thinking that if it was the fuel pump it would idle ok but as soon as you rev it ( ask for fuel) it would die?

I know that the head etc is fine as it had the top end rebuilt as well.

Too note that the symptoms are different with the stomberg than the that of the solex.

The solex would hesitate on first pick up. Swan neck was checked cleaned etc and was working but still no good hence the conversion to a stromberg.

[poppyman]

Well, that sounds like an air leak Have you checked all the vacuum hoses? It could be the pump........ They are not to expensive to replace.
It's very difficult to tell without being there......  From memory the pump should have a filter when you take the top off.
Cheers,
Tony.

[karl1]

Yes Tony I have checked for a vacuum leak with the brake cleaner and no changed in engine note.

Wont a fuel pump have problems under load and not idle?

No there was no filter strangely.  

Cars cars cars ay? 😀

[glang]

Hi Karl, the pump would have to be very poor or blocked to not even supply enough fuel for no load running. Usually a pump problem shows itself when driving as you go faster the fuel flow is insufficient and it starts to misfire. However its easy to test by disconnecting the fuel line to the carb and carefully operating the pump either manually (if it has a manual lever) or on starter motor (with engine ignition disabled) to see if squirts fuel into a container....
I too like the idea of perservering with the original carb, at least initially to get it running, because by changing it youre introducing another unknown so making things even more complicated

[Mark Hammond]

I'd check that isn't old and stale petrol in the tank first.  That will make it run badly.  The slow running jet is notorious for blocking on the Solex, otherwise it is a good match for the 6 port 1200 engine.  The Stromberg isn't the best choice of alternative, I'd consider a Weber or twin SUs before that choice.  There really isn't anything wrong with the Solex if well sorted and set up properly unless you are after more performance, and then there are a whole host of other considerations as well.

Mark

[poppyman]

Hi Karl,
I am glad others think the solex is the best option They dont usually give a lot of problems apart from a bit of poo in the jets.  I had not thought of old fuel!! That wont help, if the fuel smells of turps or white spirit it has gone off
Cheers,
Tony.

[karl1]

Wow thanks for your replies.

I was in the Toyota forum and would have to wait days for one or two replies 😀

Well you chaps know much more than I do, so weather permitting  I will fit the solex back on tomorrow.

I have cleaned and cleaned and replaced what I can on the solex with this running problem still persisting.

I would love a pair of SU but they dont come cheap.

By the way the fuel isnt old as I put fuel in the car maybe 4 weeks ago.  

So im at a loss still.  


Things done! Timing done. Checked  vacuum for leaks. Carb cleaned. Fuel supply checked!

Yet still no lift  off  

[Mark Hammond]

It might be ignition related but I’d try substituting the Petrol pump with a known good one to eliminate it first.  Just as an afterthought, it should have a guaze filter in the top so it’s likely that someone has been at it.  Check that the pump is operating and is the correct pump and that it is correctly locating on the cam.  Some pumps require a block or spacer between the engine and the pump and it’s possible it is missing or equally it requires one.

Mark

[Pete Lewis]

Apart from is there any idea the stromberg is the right spec to use on the 1200 does it have the correct needle spring and damper ring weight for this engine ??

pulsing can be its base setting is seriously too weak, and one favoirite is the rubber slivers off the fuel hoses which float and block the  back of the float needle input  
Pete

[karl1]

Mark

I was just thinking!!!! 😎

I did noting that when I start the car from under the bonnet I sometimes see a spark or arch???

But it disappears as soon as the car starts.

And yes your right there is no mesh filter in the top part of the pump for some strange reason?


What about if I rig up a bottle of fuel and hang it onto the bonnet and directly into the carb and see if that makes any difference?

That would rule out blockages or pump problems?


Thank you all very  much for your help and support.

I will keep you posted.

Regards Karl

[karl1]

Hi Pete

Well I think that I read on this forum some time ago that it was said that a single CD 150 was a good replacement for the solex carb?

I havent changed anything in the carb???

I didnt understand what you meant about this pulsing problem and solution?



If I fit the solex carb on then im back to the same mess as I was in the first place!!! 🤔

When I try to pull away the car holds back and kicks.

As said I have checked to see if the swan neck is squirting fuel and it is!

Also pump diaphragm is fine with no holes.

When the car goes past the first stage then the car drives fine.

It makes me look like a learner lol as the car bucks

[Mark Hammond]

To my thinking this is ignition related.  Most running issues are.  I’d put it back to plugs, points, condenser and coil.  Yes, first ring up a gravity fed temporary fuel supply obviously don’t drive it like that but isolate a weakness with the fuel pump first.  It will be something simple, most breakdowns or running issues on older cars are ignition related rather than fuel related.

Mark

[karl1]

Hi Mark

The weather down here in East Sussex is pretty grim today so I have had chance to do anything.

Im also worried about this electronic ignition that has been fitted and was wondering if the advance and retard system was functioning as it should be.

Am I right in believing that this advance retard works mainly on the first part of the acceleration? 🤔

[Clive]

Have you got a timing light? If so use that, as you rev the engine it should get more advance.
What have you set the timing to? about 10 degrees BTDC?

[Pete Lewis]

What i was tyring to establish is there are vastly differing specifications of CD150  that just  a  family of carb designs , was this carb suppose to be set up for a 1147 herald ???
The pulse or surging when you try to drive off can be so many things from wrong needles to fuel starvations,  and much more
We need to know just what you have fitted or guesswork wont solve anything
Is there a brass tag  with a number on one of the top camber screws?

[willows40]

Is the electronic ignition just a module in orginal dizzy or complete dizzy?
If complete dizzy that could be the problem if curves etc are wrong for that engine.
I have an mgbgt with replacement dizzy and that causes some weird running issues but on that only at higher revs so not a major problem

[karl1]

Hi all and again thank you for your support! 🙂

Well i am back to a good square one.

I have refitted the solex carb that I was having problems with!

But there is such an improvement to the running compared to the Stromberg CD 150.

I havent had chance to try to tune it again but i am sure that the problem on take off will return when hot ( may be coil )?

Plus because I have the car outside whilst I have been trying to sort the carb out I have now a nice swimming pool in the passengers foot well. (Maybe door seal )?


So, do you all think that I still need to change the fuel pump or electronic ignition too improve this take off problem?  

Thanks Karl

[glang]

Ok Karl, whats the tick over like now? No point yet worrying about pick up etc if the tick over is too erratic.
Youve checked the timing but how did you do it? A timing light is best especially with electronic ignition and as mentioned previously can show you whether the advance retard is working and how reliable the spark is. You said you saw 'a spark in the engine bay' therefore I would concentrate on getting the electrics 100% before moving on to fuel....

[karl1]

Hi, yes I have a timing light but its hard to see the timing marks so I may need to take off the front grill.

I have seen an arch when pressing the starting button from under the bonnet but only sometimes and only on start up..

Yes It seems to idle fine but likes the choke on a little.

The problems shows up  when the engines warmed up.

An other interesting thing is..... the car has been fitted with a brake servo and also some gauge inside to show you how economically you are driving (Not added by me).....

So im wondering if these two extra vacuums that have been fitted maybe taking the vacuum needed by the electronic ignition?

But this wouldn't effect the car when its hot would it????

[glang]

Its normally necessary to paint a thin line on the actual pulley timing mark with correction fluid or white paint so that its easy to see with the strobe. It should be stable and then, as you rev the engine slowly, the mark should move to show increased advance.
If the engine needs choke even when hot its probably running with the fuel mixture too weak but before any adjustments I would make sure the electrics are 100%.
With the vacuum connections they shouldnt actually take anything and you can install as many as you like however if any of them leaks, air will be drawn into the manifold so affecting the fuel mixture which could be related to the previous point....
I would work through things one at a time crossing each off the list whenyoure sure its correct

[Bitumen Boy]

Quoted from karl1

Hi, yes I have a timing light but its hard to see the timing marks so I may need to take off the front grill.

I have seen an arch when pressing the starting button from under the bonnet but only sometimes and only on start up..

Yes It seems to idle fine but likes the choke on a little.

The problems shows up  when the engines warmed up.

An other interesting thing is..... the car has been fitted with a brake servo and also some gauge inside to show you how economically you are driving (Not added by me).....

So im wondering if these two extra vacuums that have been fitted maybe taking the vacuum needed by the electronic ignition?

But this wouldn't effect the car when its hot would it????

The vacuum gauge and servo shouldn't affect the running on their own, however they do give more potential for air leaks to weaken the mixture. The fact that it likes a bit of choke - correcting a weakened mixture - tends to confirm this. I would remove and securely plug both vacuum take-offs at the manifold, then see what happens. If the running improves you can try reinstating one at a time to isolate the problem, might be the servo, gauge or the vacuum hose to either unit at fault. If no different I would still be inclined to leave them isolated until you've found the fault, the simpler things are for fault finding the better.