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Jul 26, 2009 21:55:42 GMT
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After a very entertaining, enjoyable but scary drive in the Fugitive earlier, one of the main things that I want to sort ASAP is the carbs. I am pretty darn sure they aren't 'set-up' right which results in lots of stalling at junctions/lights (fuel saving device?? ;D) and LOTS of splutter, popping, hellfire and brimstone when driving! Sounds lovely in a kinda snap, crackle & pop kinda way, but makes the car rather tricky to drive! I have NO idea at all about carbs and just looking at all the various adjusters scares me....so would like to find out how to set these up properly. Even if it means taking the car to a specialist. These are the carbs - there is a set on each side. I don't know what make they are, what model or anything....all I know is they make lots of bizzarre noises and look quite cool. Any advice about where to take them (Bristol ideally) to get them set-up correctly would be awesome. For a brief second or two between flat spots, these things seem to make the buggy fly....but then it's back to splutter pop pop bang etc.... Thanks for any help/advice
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Jul 26, 2009 22:20:22 GMT
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Thats a pair of weber IDF40 downdraft carbs... great fun to set up even when you do have a gas analyzer, rolling road and a selection of jets. Total car porn when they do work tho ;D
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To get a standard A40 this low, you'd have to dig a hole to put it in
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Jul 26, 2009 22:22:39 GMT
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Could be they just need to be balanced, rather than rejetted etc. Balancing the carbs is easy enough, effectivley adjust the throttle stops so each carb is matched, then readjust the throttle linkages to the appropriate lengths. You can sync the carbs with a potentiometer or equally by ear (length of house pipe, pop it down the barrel and listen to the sucking noise and effectivley try and match that sound on the over side). If your stuck I have a potentiometer.
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Listen for the pop-pop-pop-pop noise they make at idle, it's not really a sucking noise. Basically adjust the balance bar until they both sound the same.
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Thanks for the responses guys. I guess my problem is not even knowing the basics....Eightsix mentions throttle stops but I wouldn't even know where that is? Adjusting throttle linkages to the appropriate length? Where do I find out what the appropriate length is? (once I've worked out what the linkage is?) Potentiometer? I always thought that was a rotary switch like a volume control...... Sorry to sound so dumb. Carbs really are a new territory for me! I've owned carb'ed cars before but they were always SU carbs but they were nothing like this!! If any RR peeps living near Bristol fancy giving me a hands on tutorial in exchange for some beer tokens etc....please let me know? I'm usually OK with working on cars, but these things just plain confuse me!
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Carbs sound awesome when they are properly working, but getting them to work properly is something else. ;D I've struggled with some Webers too. I did it like Jonny69, listening and adjusting till they both sound about the same and sound healthy enough.
I always love the sound of cards, beats exhaust-sound everytime when it come to coolness in my book.
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Current: 1983 Volkswagen 1200 Mexico 2021 Kia Niro Hybrid ----- Former: 1989 Volkswagen Jetta 1990 Volkswagen Golf Madison 1996 Volkswagen Golf Wagon Happy Hour 2006 Fiat Panda 100HP 2006 Toyota Avensis Wagon
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Hi Bruce, I am just down the road from you in Hanham and happy to have a look at them. I have an airflow potentiometer so we can check the balance of the carbs to see if that’s the culprit. Hey it’s a cheap option before you have to start spending money at a garage. I just want to say though that my knowledge of carbs is limited to the Mikuni Solex / Weber style DOCE, but I am sure we will be able to suss out the basics with those. Like the throttle stop on your average EFI engined throttle body, you will have one on each carb. If you look at the bottom image you posted, the throttle stop is literally directly to the left of the rubber fuel hose that has a bolt stuck in it (look at the end of the bolt). There isn’t a specified length for the throttle linkages, what you do is disconnect the linkages, measure the airflow between each carb – balance them out with the throttle stops so they are even and then adjust the linkages to fit their new position. This way both carbs are opening and closing the same amount so each bank of cylinders is getting the same amount of air. I ran carbs on my old engine and they fell out of sync and behaved in a similar manner. The garage at Castle Combe will do carb tuning, haven’t used them for that service though.
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^^ Many thanks for the offer ^^ I'll probably take you up on that if you don't mind? ;D I just realised you PM'd me the other day about how local you are. AWESOME! I'll send you my number and an official invite down to Area52 where you will be plied with copious amounts of tea & biscuits (as well as some beer to take home no doubt) in exchange for you helping me with the carbs Tofufi is sourcing a mass of service/overhaul parts for the engine so hopefully somewhere along the way I might be able to get this thing running right lol. Thanks again, Bruce.
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93fxdl
Posted a lot
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Posts: 2,013
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Jul 27, 2009 18:34:46 GMT
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in my murky past i have played with quite a few multi carb toys (mostly motorbike) but here is a few helpfull pointers (hopefully!!!!) those k&n type filters are a pain in the butt when water is about (and you have been out in the rain) they become water logged and choke the engine and also the water is then sucked through into the carb (i remember a kwack triple that only ran on the middle pot when it rained) so drain the carbs in case any water has gotten into them and take the filters of and dry them out other than that before you start on the carbs give the engine a full service (plugs points etc) not forgetting the valve clearances it probably may be helpfull to get one of those colourtune things to set the mixture at tickover as for setting the carbs, you only need to balance left too right the route i would follow is take the likage between the two carbs off set the mixture/balance and idle speed reconnect the linkage and set the balance between the two carbs finally test on the open road and enjoy knowing how many others are green with envy there is a quick carb cleaning trick take off the filters, get the revs up and slam your hand over the intake so the engine pulls on the carb jets and any muck gets pulled through the jets and if liquid through the engine and if lumps it gets stuck into the jets so easy to find ttfn glenn ps did i say i am green with envy also a silly idea for a style, cant remember who but a yank outfit did a rail for the navy seals
fitted with
wait for it
a chevy v8 plus
wait for it
a selection of 50 caliber machine guns and if i remember properly a 20mm cannon now how about that lot for dealing with road rage
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Jul 27, 2009 20:27:17 GMT
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Think I have a colourtune kit i can post you if i can find it.. might even have a balancer too i'll have a nosey...
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Daily: Spazda Mx5
'A52's Fastest steak eater 2010'
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Jul 27, 2009 21:37:18 GMT
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i've got a balancer here too bruce if you get stuck it's only a cheapo one but used to do the job on the bike carbs when i had the x-flow - not much use with the pinto though
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Jul 27, 2009 21:38:19 GMT
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i've got a balancer here too bruce if you get stuck it's only a cheapo one but used to do the job on the bike carbs when i had the x-flow - not much use with the pinto though
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Jul 27, 2009 22:22:15 GMT
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WOW - thanks guys. Eightsix has kindly offered his help and is coming over to the unit on Weds/Thurs....Tofufi is joining in as well. Hopefully with their help and your advice I might be able to get somewhere nearer a half decent running engine I'm getting all the service parts tomorrow so things should start taking shape. Ratters, I'll try and give you a call tomorrow when I am more sober and more awake. Thanks again everyone ;D
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As has been said, before looking at the carbs it's worthwhile making sure that the valve clearances, points gap, spark plug gaps and ignition timing are correct.
Also make sure that the petrol is fresh and that the ignition coil, leads, dizzy cap, rotor arm and plugs are in good condition, and that the distributor's advance mechanism is working (a timing light/strobe is invaluable for this). Any fault with the ignition will cause running faults that might seem to be carb-related, but aren't.
After that little lot, follow the advice above about balancing the carbs, before possibly getting them set up by a pro.
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93fxdl
Posted a lot
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Posts: 2,013
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Jul 28, 2009 12:00:47 GMT
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a couple of more carb tips? as far as I can remember, often webers need to "float" a bit so they are secured with "thackary" washers (think thats the name) which are like a double spring washer and you set the tension by doing up the nut until a feeler just fits between the coils of the washers. a problem I came across a couple of times is fuel frothing where the carbs shaking froths up the petrol in the float bowl, so messing up the mixture finally a quick way of setting carb balance is to stick a piece of welding wire down each carb and trap it with the butterfly then adjust the linkage so that as you open the throttle you watch the wires and they both move at the same time. use long bits of wire so that they don't drop right into the engine also check all the mounts for the linkage so there is no slop or excess free play ttfn glenn looking at your pictures I have a similar linkage on my bugs dellortos and have had troubles with the crank from the crossbar to the carbs coming loose and sliding along the bar putting the carbs out of synch and the crossbar itself coming loose in the end mounts another possibility can be air leaks where the carb bolts to the manifold and where the manifold bolts to the head
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Last Edit: Jul 28, 2009 12:09:50 GMT by 93fxdl
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