classic car forum header
Classic cars forum & vehicle restoration.
 FAQFAQ   SearchSearch   MemberlistMemberlist   UsergroupsUsergroups 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 
Register     Posting Photographs     Privacy     F/book OCC Facebook     OCC on Patreon

carburettor set up / lumpy running
Goto page Previous  1, 2, 3
Post new topic   Reply to topic    Classic cars forum & vehicle restoration. Forum Index -> Mechanical Restoration
Author Message
1935Hillman



Joined: 06 Apr 2010
Posts: 257
Location: Hampshire

PostPosted: Sat Oct 15, 2011 5:41 pm    Post subject: Reply with quote

New regulator fitted.
Hell of a job in itself. The old one was fitted upside-down which I did not want to repeat but fitting the new one up the right way meant all sorts of issues with wires not reaching terminals etc. Oh boy, two hours to rewire nine terminals! Eventually found a position whereby the wires reach but had to move the klaxon!
Anyway, all fitted and the engine fired OK and as usual ran nicely on tickover. Ignition light dimmed but did not go out, revving dimmed it further but still did not go out. Out for a ten minute drive and sadly still stalling at road junctions (now VERY annoying) but on getting back home, light gone out and ammeter needle over to CHARGE hoo-flippin-ray!

Is this to be expected, I dont know. Do you?

Put her away now as it is getting dark but still poor running and stalling, got to be back to fuel surely. Think I am going to go for the carb rebuild

Look forward to hearing from anyone who wants to tell me something
Cheers,
Tim
Back to top
View user's profile Send private message
peter scott



Joined: 18 Dec 2007
Posts: 7113
Location: Edinburgh

PostPosted: Sat Oct 15, 2011 6:14 pm    Post subject: Reply with quote

Hi Tim,

Dredging the bottom of the barrel but you're not by any chance using a NEW black rotor arm?

See: http://www.oldclassiccar.co.uk/forum/phpbb/phpBB2/viewtopic.php?t=8225&highlight=humber+rotor+arm

Peter
_________________
http://www.nostalgiatech.co.uk
1939 SS Jaguar 2 1/2 litre saloon
Back to top
View user's profile Send private message Visit poster's website
1935Hillman



Joined: 06 Apr 2010
Posts: 257
Location: Hampshire

PostPosted: Sun Oct 16, 2011 8:33 am    Post subject: Reply with quote

Hi Peter,
Thanks for your comments and the link. The distributor was completely rebuilt by Distributor Doctor about a year ago complete with red rotor so it is something I am pretty confident about. The more interesting part of the story is that I have replaced or rewired almost everything now so it is possible that, just like the black rotor arm in the link story, something new that I have already attended to is in fact to blame for the problem.
Finding it is the tricky bit
Tim
Back to top
View user's profile Send private message
Kelsham



Joined: 18 Jan 2009
Posts: 349
Location: Llandrindod Wells Powys

PostPosted: Sun Oct 16, 2011 10:00 am    Post subject: carburretor/lumpy running Reply with quote

Buy an ignition tester from Frosts, a simple pair of calipers that you open to observe the spark whilst running the engine.
This will help eliminate the plugs, wires, distibutor etc.

What you describe sounds like blocked jets or an air leak, Might be time to have a second look at the carb, including a straight edge against the flanges.


Regards Kels.
Back to top
View user's profile Send private message
1935Hillman



Joined: 06 Apr 2010
Posts: 257
Location: Hampshire

PostPosted: Sun Oct 16, 2011 11:57 am    Post subject: Reply with quote

I think that is right. I am going to whip the carb off and send it off for rebuilding properly. I found a small company called Chatsworth Motor Spares who will do a total rebuild to 'as new' condition for a couple of hundred pounds. A new one of the same type costs the same but this way I get mine back.
Back to top
View user's profile Send private message
1935Hillman



Joined: 06 Apr 2010
Posts: 257
Location: Hampshire

PostPosted: Tue Nov 01, 2011 10:20 am    Post subject: Reply with quote

Sent the carb off to the experts for rebuild (I'll withhold their name until the results are in) Gentleman there says there isn't much actually right with the carburettor which is a bit of a shock but also encouraging in one way. Should be back at the beginning of next week when I will get it fitted and all will be well (?) Let you know how it goes.
Back to top
View user's profile Send private message
1935Hillman



Joined: 06 Apr 2010
Posts: 257
Location: Hampshire

PostPosted: Sat Nov 19, 2011 6:25 pm    Post subject: Reply with quote

Carb back from rebuilder, fitted and engine running well until I go for a test drive when the throttle sticks wide open and I have to switch her off before she blows up! I can only get home by switching the ignition on and off to accelerate and then coast as I cant push the clutch in.
Eventually return home and remove the carb. In the hand the throttle opens and returns nicely twenty or so times until it suddenly doesn't. A few more flicks of the throttle lever and every tenth time or so it sticks half open. I've just spend £££ having it rebuilt so reluctant to start messing about with it I ring the chap who says, naturally enough, it was perfect on the test bed and he can't understand it. I convince him that it is not only doing it on the car and we agree that he will have it back. He calls me a couple of days later to say that after examining it several times he found a small bristle-like hair in the piston spring preventing it from returning properly. Just got it back and re fitted. Ran well again and no sticking, no stalling and no fluffing! - SO FAR!
I will try to run her as much as possible tomorrow if I can before making a final judgement and reporting back.
Back to top
View user's profile Send private message
victor 101



Joined: 03 Apr 2009
Posts: 446
Location: East Yorkshire

PostPosted: Sat Nov 19, 2011 9:06 pm    Post subject: Reply with quote

Fingers crossed for a successful outcome.
Back to top
View user's profile Send private message
1935Hillman



Joined: 06 Apr 2010
Posts: 257
Location: Hampshire

PostPosted: Tue Dec 20, 2011 10:48 am    Post subject: Reply with quote

Well, after all that!
the problem began all over again despite now almost everything being replaced or refurbished. took the car for a spin and on returning home she spluttered and stopped. Slightly exasperated and clutching at straws I opened the bonnet and in desperation fiddled with the carb again. Got her running (poorly) and fiddled some more. It was during fiddling that my hand rested against the distributor and she ran perfectly. A quick fiddle with the distributor and it was glaringly obvious that applying a slight pressure to the side of the dist in one direction and all was well. Spoke to martin Jay at Distributor Doctor who rebuilt the unit and he asked for it back right away. Sure enough the main body had become loose on the shaft since the rebuild (possibly even in transit, who knows) causing a massive variation in contact gap causing the intermittent problem. All now fixed and back on the car and several runs have been blissfully trouble free. The moral here is: Dont take it for granted that a new or refurbished unit is 'perfect' check EVERYTHING twice. Thanks to Martin Jay for providing a prompt and thorough service.
Back to top
View user's profile Send private message
Kelsham



Joined: 18 Jan 2009
Posts: 349
Location: Llandrindod Wells Powys

PostPosted: Tue Dec 20, 2011 5:49 pm    Post subject: 1935 hillman Reply with quote

Good news, it always turns out to be something simple.
I had a problem of missfiring with my 1968 Morris 1800. After much teeth gnashing and new parts, found the nut securing the points connection was slightly loose.

My late Uncle used to run a 1930s Hillman in the 1950s. We lived in South Africa near Durban.
For some time he ran with only the rear brakes connected. Lack of parts availability.
It was very reliable, and often his car was running when later American cars failed.
If you can buy copies of the Light Car from the period, seems Rootes had some influence as there are lots of road tests and mentions of Hillman cars.

regards Kels.
Back to top
View user's profile Send private message
1935Hillman



Joined: 06 Apr 2010
Posts: 257
Location: Hampshire

PostPosted: Tue May 01, 2012 8:55 am    Post subject: Back to square one Reply with quote

Well looks like we are back to where we began with this post. The car will not run now again. Splutters on the drive and splutters worse when driving. Had some help from an MG specialist of my acquaintance but he is an SU man through and through. He got her to idle and run but even with the mixture screw almost wound right in she still puts an inordinate quantity of fuel into the inlet manifold and after a few minutes of trying to start her the manifold is literally awash with petrol. Plugs are always black and sooty and tailpipe residue the same. I now have two identical carburettors, both rebuilt using factory jets and settings and both behaving the same way.

Does anyone out there know anything about downdraft carbs?

A couple of oddities which may have a bearing but I am not sure. My car does not have the correct Aero Minx inlet or exhaust manifolds. I think they are standard Minx ones. I do have a correct inlet manifold and there are two distinctive differences (1)The correct one is taller, i.e. the part that you bolt the carb to is stretched up quite high (2) From old pictures I have of the correct one it seems to have a copper fuel type line going into (or out of) the manifold at its base where the manifold branches out to go to the engine. What could this be for? and what is it connected to? I am beginning to see now why so many Aero Minxes have SU and Zenith carbs fitted. Maybe the Stromberg carb just wasnt very good!

Answers please ladies and gentlemen
Back to top
View user's profile Send private message
peter scott



Joined: 18 Dec 2007
Posts: 7113
Location: Edinburgh

PostPosted: Tue May 01, 2012 9:46 am    Post subject: Reply with quote

Hi Tim,

I think you've found the problem. You say that petrol is pouring into the manifold regardless of what setting you have for the slow running adjustment.

Clearly this is not right. I don't know what carburettor type you have but most control an air bleed with the mixture screw (others control a small petrol flow).

I suspect you'll have an air bleed. Can you see where the petrol is coming from? I would suspect that your float level is too high and it's just pouring out of the main jet. There should be some method for lowering the float level.

HTH

Peter
_________________
http://www.nostalgiatech.co.uk
1939 SS Jaguar 2 1/2 litre saloon
Back to top
View user's profile Send private message Visit poster's website
Roger-hatchy



Joined: 07 Dec 2007
Posts: 2135
Location: Tiptree, Essex

PostPosted: Tue May 01, 2012 11:06 am    Post subject: Reply with quote

Clutching at straws here.

I don't know your carb float set up.

I run a twin SU (MS2) set up

On my SU's I had to replace one of the float chamber covers as it had a hairline crack and was always damp,

I had the same problem with flooding, could set up the correct fuel venturi to jet level, float hight, but when the cap was replaced, and tightened down, it would flood.

I changed the float chamber caps over only to find the second carb flooding.

I Finlay discovered that the replacement cover is softer then the original, well that's my theory, when the cap was replaced and tightened down the needle/jet set up was somehow altered.

I managed to cure the problem by only just pinching the bold down hand tight plus 1/8th of a turn, (one flat).
Any more and it floods again.

Just a thought
Roger
Back to top
View user's profile Send private message AIM Address
Display posts from previous:   
Post new topic   Reply to topic    Classic cars forum & vehicle restoration. Forum Index -> Mechanical Restoration All times are GMT + 1 Hour
Goto page Previous  1, 2, 3
Page 3 of 3

 
Jump to:  
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
OCC Merch link
Forum T&C


php BB powered © php BB Grp.