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<x-charset iso-8859-1>Jason wrote: >Your problem is likely a vacuum leak. When you rebuilt the carbs, did you >lightly plane the top and bottom halves on a flat surface with 220 or 400 >grit wet/dry sandpaper? This will let you know if you have any "high" or >"low" spots, which indicates that your carbs may be warped from engine heat. >Yes, you might also look for slack in the throttle shaft bushings. ANY >slack is too much. I sanded down the bottom of the main carb body where it joins the throttle plate- it was very bowed but I think from overtightening of the mounting nuts rather than heat. The Throttle bodies themselves looked fine. I did notice a fair amount of slack in the throttle shafts which was worrying. I reckon that this is the most likely source of an air leak but I've found a great company here in UK who will rebush the throttle shaft with PTFE lined bushes, line reamed to fit the shaft snuggly for just 15GBP per carb. This sounds very reasonable to me and would probably last a lot longer than the original steel on alloy bearing. They charge 159GBP for a complete refurb of both carbs, way more than I want to pay, and anyway the rest of the carbs looked fine. They specialise in restoring vintage carbs to concourse cond. and had listed T3 PDSITs NOS for 50GBP each- they don't have any left ;-( I have to check if they can supply me some new idle mixture screws- I read someone say that these should come to a sharp point- mine don't. The RHS one is more truncated than the LHS, but I checked the tip under a microscope and it didn't look broken. It came to a turned looking flat end about .5mm dia. which appeared to be plated the same as the rest of the screw. How sharp a point did these really come to? Dave Hall wrote: >Can you check the CO level? > I find about 3% CO works OK on my Twin Carb. Could be yours is fine and > there's air getting in - at tick-over speed there is quite a big suction in > the manifold to screw up the mixture. > 20 mp(imp)g seems a bit low, > but maybe not far off for slow cold short journeys. > Timing and valves are also important - are these OK on yours, Mark? I've checked and re-checked the valves and timing- they seem fine. The weird thing is that when I first got the car, the valves had next to zero clearance and the ignition was way too advanced-like 30 deg at idle! Yet I'm pretty sure that it ran at least as well as it doesn't now! If I increase the advance it does seem to pick up. I'm contemplating removing the pulley wheel to check that has its woodruff key- maybe I'm really retarded after all 8--o I haven't had the CO level checked yet- when I'm happy that everything in my control is as it should be, I guess I should- I'm sure it would tell me a lot. I am still getting misfiring for a while at start up but that lessened when I enriched the mixture 1/4 turn and changed one of the leads for a fat silicon one. I think I need new HT leads and am in the process of (trying) to get some really nice Beru leads and connectors. With that sorted, rebuilt throttle bodies, and Jim's uni-syn to get the balance right, I'm really hopeful that things will tune up nicely. So what do others get with "healthy" stock (carbed or FI) engines in town driving- would be interesting to get an average. SIR.LANCE wrote: >that or they dont have the idle set proporly and are useing the mixture >screws as idle? >so to get a good running motor u run more fuel than air? kinda like a cholk? >rather than letting more air in via the butterfly valves? I don't think this would work as if you keep riching it up, the engine idle slows and runs uneven again- it needs air as well, Its not running THAT bad- your engine doesn't run as well cold with choke as it does when its warmed up- it just shouldn't stall all the time. Thanks all for all the input- Bryan if I discover the secret I'll let you know Mark Seaton Orange '73 1600TA London ------------------------------------------------------------------- Search old messages on the Web! Visit http://www.vwtype3.org/list/ </x-charset>