Weber carb problem

[danny_nelson]

Re: Weber carb problem

Hi Mike to add to the above comments.
I think that if your dizzy timing had slipped you would stand a chance of seeing a different reading on your temp gauge after prolonged running. This is a very difficult problem to pinpoint without having hands on the car. However
there are some useful comments by members. Rule of thumb for uneven idling faults are leaking carb flange or manifold gasket. Loose idling jets or auxiliary venturis.
Throttle spindle worn. Secondary throttle valve partially sticking open. Leaking ignition advance tube. From a performance point of view, being as the engine runs okay when you get going. I would think this points at the fuel side . I would think that if the problem was elect it would be there all the time in some way. I think you are right to consider a new carb because you are obviously not happy with the one you have, and you had trouble with it when you first got the car. I would not worry to much about the spec of your engine, but I would renew the inlet manifold gasket,
and you should get a new carb flange gasket with the carb.
I have always refered to these as the emulsion block.
As far as the prolonged starting I agree with the above comment and it is just the pump cranking up the petrol. Not a bad thing if you thik about it because the last thing you want a pinto to do is to start instantly because the cam is dry! If it needs cranking for a little time at least you know that the crank has a coating of oil. Years ago we use to put a switch on the coil to keep the engine from firing untill we knew that the cam was lubricated. Then throw the switch and start up.A tapping noise told you that another pinto was close by!

[danny_nelson]

Re: Weber carb problem

Sorry about the spelling I have spelt think thik!
Good Luck with the problem

[gouldsborough7]

Re: Weber carb problem

Thanks Danny
I sympathise with the spelling problem, which is not helped by an absence of an auto-spellchecker facility and the small window in which to type the messages.

The more I think about my problem with the Berli, the more convinced I am about the carb being the major problem. During the jam on the M25, the tickover gradually got more & more lumpy and slower, and required lots of prodding on the go-pedal to ensure it pulled forward the 5 yards each time the traffic tried to get moving. So I kept the revs up on the 2nd choke-knob which only deals with the revs.

However, much later in the journey and nearer home on local roads, I was in a small queue at traffic lights and decided that I could push the choke fully in, only to result in the engine dying on me. Re-starting was again a pain, with backfiring through the carb. Needless to say, the choke knob was re-adjusted to keep the tickover revs above 1000rpm until I got home.

I am expecting the new carb to arrive today, so hopefully I will get it fitted over the weekend, and report back the conclusions.

Cheers
Mike

[dogoncrazy]

Re: Weber carb problem

Mike
Good luck with the installation. Much has been said already about the problem you've experienced, all of which could have been the source.
My theory [and that's all it is!] is again a blockage in the idle circuit, pulling the choke out brings up the revs and thereby brings into effect the transition circuit of the carb.This is the reason that when you are setting up the carb to get the best ie smoothest idle you have to be aware of NOT screwing the fast idle screw in to far.
I would make sure that fuel hoses are in good condition as any breakdown of the rubber internally could result in the same thing happening [I speak from experience on that one!!]

[macdonald.dm]

Re: Weber carb problem

While you're swapping the carbs, Mike, I'd take the opportunity to remove the manifold and check the surfaces - very straight-forward job. Your symptoms sound very like mine (tho' not quite as severe - I couldn't get mine to run below 2k rpm!), and it was due to a TINY leak.

(PS. Spell-checks - change your browser to Firefox, and load their checker...)

[danny_nelson]

Re: Weber carb problem

Good point Alan, whatever it is it would seem to be in the idle.

[b_caswell]

Re: Weber carb problem

I would also do a compression check as a dodgy exhaust valve that is sticking or starting to burn away can cause similar symtons especially as you said the engine sounded as if it was running backwards!!!

[b_caswell]

Re: Weber carb problem

Symptons Symptons Symptons must try harder

[terryreed1664]

Re: Weber carb problem

This is very exciting, its like reading a book, cant wait for the final chapter. What will the final out come be!!!! will it work!!!
Terry

[b_caswell]

Re: Weber carb problem

AH another thought... Mike that anti running on valve you fitted recently...is it working properly?????? ie is it shutting correctly and not allowing an air leak.

[KitCarGirl]

Re: Weber carb problem

Hi Mike

Thanks for starting this thread. I have carb problems and am going to get a new one so am following closely with all the advice. Looking forward to the final chapter.

And the spell check jibe was noted. It's been on the wishlist for a long time so I'll try and bring it to the top. Donnie's right though, Firefox spellchecks as you go. It's great!

[lizbillings]

Re: Weber carb problem

I have carb problems as well. Wondering whether to splash out on a new one (is there such a thing) or are they re conditioned or to get an overhaul kit. The common thread is that the donor cars are 30 years old plus and maybe this fuel we are using now is not helping. Regards everyone Liz

[gouldsborough7]

Re: Weber carb problem

Yes Liz, I bought a brand spanking new Weber 28/36 from www.fastroadcars.co.uk in Newport, Monmouthshire. I got their details off an e-Bay auction to start with, but was unsure precisely what Weber carb to go for and rang them direct.

The guy at Fast Road Cars was very helpful and advised me to go for the 28/36, and I opted for the manual choke version. Strangely, an auto-choke version is available at extra cost, but who would willingly want one?

For those who want to follow my route, in round figures the cost was £150 (carb), £8 (flange gasket) & £15 (postage) = £173. This is far cheaper than I had seen elsewhere, and the guy was happy to provide free advice by phone if things did not work out as well as expected.

I fitted the carb without a hitch, but failed to get the engine to run, only to find that I also had a problem with a burnt main HT lead connection between dizzy & coil. So I have just bought a new set of silicone leads, and while hand was in wallet a new dizzy cap and rotor arm - so another £23 total (good price) from a local car shop . No point spoiling the ship for a ha'pence worth of whatever!

On reflection, it is conceivable that my M25 experience was largely the fault of the duff lead, but I had experienced the same symptons in a smaller traffic jam some 5 months ago. So I cannot imagine if the lead was faulty then, that it would have survived this length of time.

I'll log another message in a day or two, with hopefully a successful outcome.

Cheers
Mike

[lizbillings]

Re: Weber carb problem

Hi Mike. Have you kept any money aside for a calendar? £8 including postage. I shall be interested to hear how the car runs. Regards Liz

[Dane_Rescueman]

Re: Weber carb problem

I have recntly changed my engine over to EFi. Up until the change the old engine, despite low compression on N°3 cylinder (knackered bore), ran correctly with my 32/36. The emission figures were very good for the engine. I would be happy to let the carb go in exchange for a suitable number of Bank of England beer vouchers. It has a Webcon conversion to manual choke and has had an overhaul during the last three years. I can let it go complete with manifold, choke cable and little chrome pancake filter.