jk fuel valve

[wokinggaz]

when i brought my van it had some mickey mouse carb on it which gave me loads of probs. i have replaced it with a twin choke weber courtsey of martin at webcon( my uncle). Fitted in the fuel line is a regulating valve to restrict the fuel which i found on jk's website. has anybody has any dealings with these, ie: what setting should it be on and how do you determine the setting?
Cheers Gary

[jason k]

what engine?

and i take it you mean a fuel pressure regulator?

[Ian Hulley]

when i brought my van it had some mickey mouse carb on it which gave me loads of probs. i have replaced it with a twin choke weber courtsey of martin at webcon( my uncle). Fitted in the fuel line is a regulating valve to restrict the fuel which i found on jk's website. has anybody has any dealings with these, ie: what setting should it be on and how do you determine the setting?
Cheers Gary

I guess it might help if you told us which engine you have and then we'd know which 'mickey mouse' carb you should have had in the first place, many people have BIG trouble with Weber carbs and they are mega thirsty. As for the valve ... why don't you ask your uncle ?

Ian

[wokinggaz]

good point, its a 2.0 cu. the carb before was a weber copy, it didn't have any manufacturer name or markings on it and had been made to fit, not sure what it was off. It is the pressure regulating valve im talking about which is inline after the pump.
spoke to my uncle about it and he's never really seen one fitted and seems to think there's not any need for it.
thought i'd see what you guys thought?
cheers Gary

[Ian Hulley]

There's normally an inline non-return valve on the return line back to the tank ?

Ian

[wokinggaz]

yeah theres that too. just not sure whether i actually need this pressure valve or not. Main reason i ask is i've got a bit of a flat spot on acceleration. I've checked the timing, set the co2 to 2 1/2 % and idle is at about 900rpm, just wondering if its restricting fuel, not tried adjusting it yet, could try that and see if it makes a difference

[toomanytoys]

Does it have the factory mechanical pump? or an electric one fitted? do you have a fuel return line back to the tanK?

Mech pump must be getting tired now so unlless it looks newish, factor on having to fit an electric pump (mech ones are/were not available), most of the electric pumps can supply too much fuel for the carbs.. hence a press reg, if there is no return to the tank then that will give too much pressure.. I cant remember if the CU originally had a return to tank, but 1.6 CT and all other petrols do..

I'd prob set the thing to half way, see if you get flooding..

[wokinggaz]

its got an electric pump and i think its got a return, will check tomorrow. i,ve set it to half way at the mo. suppose the best thing is to just adjust and try it down the road

[toomanytoys]

Still have the dual vac dizzy? are the correct dual vac points on the carb? (not usually!!)
If only single vac, do you have the vac attached to the outer connection, and then timed up at 7 deg BTDC vac dissconected..

Is the vac advance unit working correctly? a leaky diaphragm will give hessitation when hitting the throttle from idle..

Its also worth ducting a little warm air to the carb body especially in winter..

Now, dont go having a hissy fit about what I am going to say here...
But ....

Most peoples experience of the webber conversion is that the jetting is "generic" and not set up for the engine, this requires a rolling road session by an experienced operator.

Now maybe you can shed some light on this as you have some inside info.. maybe its kits supplied via other sources that cause the issue.. I dont know.. so please dont think I am attacking it/your uncle... I AM NOT.. we realy could do with finding out more info, as it comes up quite a bit..

Have a search on here with "webber", lots have done conversions and lots have had issues and needed to rejet.. thats a fact.. I have a webber I want to use on my engine and it will need jetting for a number of reasons, but thats a different story.. They are a good carb and when set up well work great..

[bigherb]

Pressure regulators should normally be set to 3 psi. Press and turn the knob so the pointer lines up with 3 on the outer ring.

[wokinggaz]

Right firstly no hissy fits, im chilled dont panic . Ok is dual vac dizzy connected to the carb with only 1 vac pipe to the outside point of the vac unit. I actually timed it to 5' with the vac disconected, but gotta be honest it wasn't a steady reading it jumped a bit. plan to pop into work tomorrow and recheck everything, and see what the advance is doing throught out the rev range. autodata gives me readings for set rev ranges for checking advance correctly, will keep you posted on what i find.The only other thing is the other vac take off on the dizzy is unblocked, is this right or should it be blocked?
With regard to weber carbs i think they probably are generic. when i got mine i gave my uncle my old one and he was going to rebuild it until one of his lads got it apart. aparently there are a lot of copies going around with cheap parts inside that have a very short lifespan. these are exact replica's without the weber logo stamped on them being sold as the genuine ones. he's said he seems to be seeing alot more of these from people wanting rebuild kits but it wont work due to different sized seals ect. Im gonna call him tonight and talk about the jetting side of things so i'l hopefully be back with some answers.
3psi on the pressure reg, the answer i was after, many thanks mine was set on 5 so i'll adjust and try

If anybody needs any data ie, timing settings, torque settings, tuning data or diagnostic codes for newer vehicles i can get it from my autodata system.just shout

[toomanytoys]

Ok, phew..... thats fine then..

OK. that would explain a good bit.. webber copies, that is.....

Yeah, leave the inner vac unblocked.. "moving timing would poss be due to the mech advance sticking, so a good clean and spray with light oil should help..
It should advance quite quickly IIRC, and top out around 32-34 degrees above 3000 rpm.. I think... no vac of course... but then you should be able to tell us what the autodata system says

[bigherb]

I actually timed it to 5' with the vac disconected, but gotta be honest it wasn't a steady reading it jumped a bit.

Did you disconnect and connect the plugs together on the digital idling stabiliser otherwise the timing will bounce about trying to compensate.

[toomanytoys]

I actually timed it to 5' with the vac disconected, but gotta be honest it wasn't a steady reading it jumped a bit.

Did you disconnect and connect the plugs together on the digital idling stabiliser otherwise the timing will bounce about trying to compensate.

bugger... I knew I had forgot summat......... Nice one... of course if its still fitted...

[wokinggaz]