carb issues after ultrasonic clean and soda blast

[jonnyshaw49]

hi guys ive finally got my gt on the road after 5 years in the barn. I took it to scoff to be set up on the rolling road as im running a bigger turbo etc. when we got it on the rollers the carb was playing up and wouldnt idle and was very lean. scoff said it would be best to get the carb ultrasonic cleaned as all the calcifying in the bowl could have been blocking the passageways and idle jet and making it lean. so i sent the carb off last week to be cleaned and soda blasted as the build up of calcium was bad. now i have the carb back and rebuilt and back on the car but having serious afr issues. i have got the car to idle at 13's but as soon as i apply any throttle the afs shoot to 10's and the car sounds like its missing. which is seriously rich.when i drop off the throttle the afrs shoot to 17's and engine sounds lumpy. Then after 10 or so seconds returns to the 13's. i have tried allsorts such as trying a new main jet and a different enrichment side of the carb which has the second stage. ive tried resetting the pump jet with 7mm drill bit, tried changing the other jet in the bottom of the bowl as the rubber was split. none of this made a difference. when i sent the carb for cleaning i removed the emulsion tube with the m4 bolt and i have put it back. i was unsure of which way the tube went in but looked on another spare carb i have and copied it but still unsure is its the right way. i put the tube in with the little notch at the top facing towards the front of the car. is this the right way? sorry for the essay but i am absolutely baffled now! appreciate any help thanks

[Wallace]

To start with, the emulsion tube will basically only go in 1 way....and I don't understand what u mean by M4

There is a red fibre washer that you put in first to seal the emulsion tube, if this isn't there that it could be a reason for the 10's as fuel can leak through it so to speak

When the cars running give the throttle a little blip,with the lobster off, look down the carb and make 100% sure it isn't leaking around there.....

[jonnyshaw49]

hi mate the bit i meant by emulsion tube is the brass tube that the air corrector sits in. to remove it you have to srew an m4 bolt in and use a puller to remove it. im not sure if i have this the right way round. i have checked the emulsion tube and the red fibre washer is in place and fuel isnt leaking down the venturi. when i apply throttle and look down the venturi fuel absolutely gushes down the centre of the carb like a tap and i can see it puddling on the butterfly at the bottom. fuel just seams to be pouring out which i dont think is right. i have taken the carb in bits again today to check everything i can and i found 2 things the pump jet spring was in the wrong way and the throttle screw had snapped off but i dont think these are the problem. the guy from the ultrasonic place said the carb could have gone porous or that something is still blocked and recommends an acid clean but im not sure.any ideas? appreciate the help as im puzzled now!

[Wallace]

Nope no ideas of real help, bit above my knowledge of the carb

Just the basics which it sounds like u have covered, but the bits u say are broken will obviously all effect the overal functioning so should absolutely be dealt with

Post up what you find

[casper]

Check the needle valve is sealing.Check for splits in the diagphram in the enrichment block.

[dangerous dave]

Alan123 put about 4 carbs through his ultrasonic and had issues, it's difficult to tell if its from before, because of the ultrasonic or just because carbs always play up after you touch them..

We came to the conclusion that the carbs are getting so old the insides are likely to be shafted after all these years and not they just get blocked, choked, clogged, then you clean them and they open up to much.. The other problem might be the cleaner breaks the dirt/grime/deposits free but can't quite get it all out (on the home kit he has) and the. Clogs up again..

In the end he got a workin carb off another car and we all still wonder why none of them ran right..

[michael tierney]

u still might have soda/grit behind the venturi ....there's a small hole in it to transfer the idle to the venturi on open throttle!! u can press/pull the venturi out using a nut and bolt M12 and a suitable washer to make sure!

[jonnyshaw49]

hi mate ill have a go at that! i think my problem has just become much worse! i had put 10 w 40 oil in the other week before the run down to scoffs and everything seemed fine but now the car is smoking at idle and on a run it seems to clear. its gradually getting worse.This could be why my afrs are going so rich as the oil is burnt though the exhaust and passes the afrs sensor in the downpipe. i noticed oil seeping from the joint on the manifold to the turbo and also the rear of the turbo to the turbo elbow. i thought it could of been the oil too thin and coming from the engine through the turbo. i changed the 10w 40 for 10w 60 to see if it was just thin oil. i took the car for a good run to burn off the old oil but it still seems the same. ive taken the turbo off and inside the manifold seems dry as a bone just sooty. i took the elbow of the turbo and that also seems clean but looking through the turbine fins i can see oil residue! do you think this turbo has gone? if it is im gutted because got it off here brandnew and its never been on the road except for the hour drive to scoffs. its just been run in the garage but maybe the seals could have gone dry being stood for 3 year and only run every now and again

[Adam 005]

10/40 is fine for a GT.

[Fordy]

Check your oil return pipe is free flowing and not blocked, if its ok then it seems it could be a fault with the turbo

[jonnyshaw49]

hi thanks for the reply. i had a closer inspection of the turbo today and there seems to be a bit of play in the rear turbine. side to side and in and out. i can virtually touch the turbo housing with the turbine if i move it side to side. Think its definately the turbo. shame as the car has only done about 100 miles since the turbo was brand new! The front wheel doesnt seem to have much play in it though. Any recommend any good turbo builders? if a turbo only needs a seal do you still pay the full cost of a rebuilt . same as if the turbo needs loads of parts? do they balance the wheel as they build them or something?

[michael tierney]

the turbo probably needs an exhaust housing....they crack and make contact with the turbine a kit is fairly handy to fit....just mark everything up!! http://www.ebay.co.uk/sch/i.html?_tr...at=0&_from=R40

[jonnyshaw49]

hi mate mine is a hybrid turbo so not sure what housing i would need. i know where you mean on the exhaust side where they normally crack but mine isnt cracked. the turbo still looks like new! just going to send it off to get checked over i think!