weber carb is stupid

Hi all.

Series 2A with 34 weber on it - it's stupid. refuses to idle half the time - trying to drive in traffic is a total nightmare, i got extremely annoyed with it... caused a frosty silence from the passenger seat :doh:

it's not the idle speed setting 'cos sometimes it's fine. something with the choke maybe? all else carb wise is fine, i had it apart and cleaned it all out and it made no difference. when it's going well I can mess with the idle screw and change it, but it also has a super-low unadjustable idle which I think causes the cutout. might this be a different jet being used instead of the idle jet?

got an SU lying about that's the same size as the Powerplus one - is this the answer? not above making manifold(s)

cheers, an info or advice welcome

Dunno, but my ICH34 never seems to have any problems...should rebuild it at som epoint to make it perfect, but cold starting is never a problem, nor is idle. The only thing it does now and then is freezes up - but only tends to do this at -3 or colder and not all the time. Turning off for 5 minutes to let it warm from the engine heat gets me going again...I dont mind too much

are you sure its the carb at fault? have you checked your ignition system and timing, i have seen countless people throw good carbs off a car just to find their ignition system was at fault

you need to get ontoo the haynes website wich has a manual on setting up webber carbs it is the unadjustable idle jet they dont adjust they simply screw out and the tiny hole in the middle is its only setting the webber manual should tell you what sized jet hole you need for your engine just a question of changeing the little brass jet nut thingy usualy the jet out of a 2.3 ltr sierra or cortina carb will be the right one as they were all webber
i was tought all this by a verry old man in a tuning station bout 10 yrs ago as i was his apprentace for bout 12 months before he died
and dont be scared of the twin choke webbers neither you set one side right and the other will follow with a little tweak of the butterfly valve flaps
if memory serves me right a sierra or cortina crusader carb off a 2l car should run fine on a series 3 2.25 petrol engine no probs
hope this helps
regards john

ps the little idle jet your looking for is in the middle of the main air flow passage bout half way down easier to get at from underneith with the carb off

Autodata Carburador

http://www.scribd.com/doc/15882111/WEBER-CARBURETTORS

erm just a thought but have you checked for airleaks?

cheers chaps

timing is OK - will check again tho

defo no air leaks, was the first thought.

will read some of them things and see if i cant fix it

1396midget said:

defo no air leaks, was the first thought.

Click to expand...

is the carb base and it's mount flat ?

should be, tested fer leaks by squirting stuff about and it didn't change it. seems to be random when it chooses to idle low, might well be heat related, thort it mite be fuel vaporisation?

will have another poke at it this evening, some buggers gone and made it all dark at half 4 now though....

A little trick of the trade is to start the engine up with the air filter off,rev the engine to 2-3000rpm from under the bonnet and put your hand over the top of the carb,it'll feel like it's gonna suck your arm off but don't worry it won't,the engine will start to die and kick black smoke out,keep your hand over the carb untill it nearly cuts out and then take your hand off,it will cough,spit and fart and run like a bag of crap for a few secs then clear.(you will have to rev it to keep it going and clear)Do this a few times and if there's any crap in the jets it'll all be sucked out

certain webers can be setup differently, the choke tube, emulsion tube, main and power jets are all replaceable, if you have the wrong ones that could be the issue.
Emulsion tube and choke tube would be the first to look at with an idle issue.
If the carb is correct which it would be if its an original landy one, then 2 other causes are excess vibration which is unlikely if the idle speed is correct, or a float chamber issue, I seem to recall theres a bleb moulded into the float chamer body to tell you where the level should be, with the float in its usually level with the jet orifice.
Having said all this the fault is most likely a setting issue, the haynes article refered to is well worth the time to read.
Looking at your username you should be no stranger to the SU, they are a veritable carb.