nick69 Posted June 9, 2007 Share Posted June 9, 2007 Guys,Im having real trouble here. Im trying to tune the CD150 strombergs on my gt6 at the moment. So far ive got it so the car idles at 900-1000rpm which to me is a bit fast. At random intervals fuel will come out of the float chamber vent holes, well actually only the right hand one. It happens more when the car gets close to normal idle speeds.I replaced the O rings on the jet assembly, new diaphragms, new needle valves.Ive tried turning the distributor and it just made the idle VERY rough going either way.So at the moment the car runs a bit rough, uses a lot of fuel, at an idle speed of 900-1000rpm and the throttle response is pretty poor too.The reason for doing this was because the car ran fast and very rich and used £10 of fuel in just 25 miles. There are no leaks from anywhere btw.Please someone help me with this as im stuck trying to sort a problem I have NO IDEA how to fix. :(Thanks as alwaysNickIve read the manual over and over and it seams to be written in some form of language i dont understand!!! Link to comment Share on other sites More sharing options...
CharlieB Posted June 9, 2007 Share Posted June 9, 2007 [quote by=nick69 link=Blah.pl?b=spit,m=1181401720,s=0 date=1181401720] At random intervals fuel will come out of the float chamber vent holes[/quote]This sounds like the needle valve sticking open. If its anything like an SU needle valve even new ones can stick, I gently sanded the sides of mine to allow them to move freely.I assume you have a fuel filter? Link to comment Share on other sites More sharing options...
nick69 Posted June 9, 2007 Author Share Posted June 9, 2007 The needle valves seem to so incredibly loose I just cant see them sticking???Yes I have a filter just before the first carb. Link to comment Share on other sites More sharing options...
CharlieB Posted June 9, 2007 Share Posted June 9, 2007 Could the float have a hole in it? Link to comment Share on other sites More sharing options...
nick69 Posted June 9, 2007 Author Share Posted June 9, 2007 I didnt see one when I looked at them. Is this an indication that the float is sinking then??Could it be bad flaot level adjustment?? Link to comment Share on other sites More sharing options...
CharlieB Posted June 9, 2007 Share Posted June 9, 2007 Well if the float is full of petrol it wont close the needle valve & you'll get petrol out of the vent hole.Float level adjustment, possibly, not sure? Link to comment Share on other sites More sharing options...
nick69 Posted June 9, 2007 Author Share Posted June 9, 2007 Well im going to have to take them both off the car tmw and start again and see what happens.Does anyone know of someone /where I can get the car tuned in the Southwest? Im located In Wiltshire btw. If I can only get it running without fuel going everywhere ill take it to someone for the final/proper tuning because I cant do it. Link to comment Share on other sites More sharing options...
Deleted User Posted June 9, 2007 Share Posted June 9, 2007 Waaaaaaaaaaaaaiiiiiiiiiiiiittttttttttttt!Fuel leakage is certainly float level adjustment.They each have a tab on, the tab lifts the needle to release the fuel.The valve should be fully down until the float is about 1 thou(!!) from being at the top of its travel.Common trouble with strombs! Link to comment Share on other sites More sharing options...
nick69 Posted June 9, 2007 Author Share Posted June 9, 2007 Ah I see. I thought the valve worked the other way around!!!Ill get on to that tmw then. Then all ive got to do is set the mixtures and balance them somehow! Link to comment Share on other sites More sharing options...
nick69 Posted June 9, 2007 Author Share Posted June 9, 2007 The manual I bought for the carbs only has 2 pages on the CD150s. Crap really. Link to comment Share on other sites More sharing options...
Tryumf Posted June 10, 2007 Share Posted June 10, 2007 In my experience once you start having trouble with strombergs "especially old ones" the best thing you can do with them is remove them and drop them in the nearest dustbin and try and source a new pair, There are plenty of "new" old stock carbs around if you look, you could try contacting Nigel (the carb man) I bought a new pair of him for 45 pounds and never looked back,He has a shop on ebay! could be worth a try.......David http://stores.ebay.co.uk/N-J-WIILLIAMS-CLASSICS Link to comment Share on other sites More sharing options...
Deleted User Posted June 10, 2007 Share Posted June 10, 2007 [quote by=David6958 link=Blah.pl?b=spit,m=1181401720,s=10 date=1181431774]In my experience once you start having trouble with strombergs "especially old ones" the best thing you can do with them is remove them and drop them in the nearest dustbin and try and source a new pair, [/quote]Excuse my french, but that is ballcocks!A rebuild is simple as pie if it come to that, but new diaphragms/valves/floats solve most things. Link to comment Share on other sites More sharing options...
GT6Steve Posted June 10, 2007 Share Posted June 10, 2007 The way to test floats is to immerse them in warm/hot water. The heat will expand the air inside and bubble from cracks too small for the eyes. Link to comment Share on other sites More sharing options...
nick69 Posted June 10, 2007 Author Share Posted June 10, 2007 Well ill test them this morning and see where we are then.Thanks for help guys Link to comment Share on other sites More sharing options...
Steve AKA vitessesteve Posted June 10, 2007 Share Posted June 10, 2007 [quote by=nick69 link=Blah.pl?b=spit,m=1181401720,s=9 date=1181428729]The manual I bought for the carbs only has 2 pages on the CD150s. Crap really.[/quote]Have you seen the Haynes manual on Strombergs? It has 60 pages.I agree with GT6Jim rebuild em - the kit has all the bits and the job is not hard. Link to comment Share on other sites More sharing options...
nick69 Posted June 10, 2007 Author Share Posted June 10, 2007 I have put new diaphragms, needle valves, o rings and gaskets in.The floats have just been tested and they are fine. The needle valve is sitting and working fine. The car runs now but after sitting for 1 min without choke the fuel still comes out of the Float chamber vent holes???? Link to comment Share on other sites More sharing options...
nick69 Posted June 10, 2007 Author Share Posted June 10, 2007 Also could the fuel be coming out due to the car not being taken for a run??All the adjustment has been done by start/stop on the drive!!I just took the car down the road and the fuel hasnt leaked at all!!!!Man I wish I knew what I was doing!! LOL Link to comment Share on other sites More sharing options...
Steve AKA vitessesteve Posted June 10, 2007 Share Posted June 10, 2007 If you are using an electric fuel pump it may be pushing too hard for the needle valves to resist at times. A normal mechanical fuel pump should be OK. Link to comment Share on other sites More sharing options...
nick69 Posted June 10, 2007 Author Share Posted June 10, 2007 Its a new mechanical pump. Link to comment Share on other sites More sharing options...
Deleted User Posted June 10, 2007 Share Posted June 10, 2007 If you need the manual, you're already lost ;D Link to comment Share on other sites More sharing options...
nick69 Posted June 10, 2007 Author Share Posted June 10, 2007 I can tune american carbs all day long but these things are weird!!!!!lol Link to comment Share on other sites More sharing options...
Deleted User Posted June 10, 2007 Share Posted June 10, 2007 The fuel is coming out, due to the needle valves being opened.Keep bending that tab until it doesn't! Link to comment Share on other sites More sharing options...
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