dugong Posted March 11, 2014 Share Posted March 11, 2014 I think the Amazon is angry at me leaving it in Crewe for a year. Went for a farty drive in the Amazon. Slowing down for a side road off a main NSL carriageway, I braked from 55 to 15 to make a left turn and the engine cut dead. Coasted to a halt trying to start the engine. Tried briefly to crank the motor with a very strong smell of fuel assailing my nostrils. Popped the bonnet and could see fuel gushing out of the float bowl. I suspect the needle in the float valve is sticking and not closing because the fuel pump is overpowering it. I'd been told its flow rate wasn't consistent. That's my theory. Anyone else want to volunteer one? I have very little to no money left to spend on this thing. It's driving me mad. Link to comment Share on other sites More sharing options...
michael1703 Posted March 11, 2014 Share Posted March 11, 2014 Punctured float? Detritus from sitting about? Link to comment Share on other sites More sharing options...
Inspector Morose Posted March 11, 2014 Share Posted March 11, 2014 Yup, sound like a ruck of shit floating about mixed with stickiness due to lack of exercise. Link to comment Share on other sites More sharing options...
dollywobbler Posted March 11, 2014 Share Posted March 11, 2014 I'm trying to recall what it was that made my Vitesse-engined Bond Equipe do this. I farmed the job out, so it's a bit of a struggle. Some diaphragm or other had failed I think. Quite exciting having all that petrol squirting all over the engine. Link to comment Share on other sites More sharing options...
dugong Posted March 11, 2014 Author Share Posted March 11, 2014 Punctured float? Detritus from sitting about?Float is new. Carb has been ultrasonically cleaned. No crap in the lines, all been purged. Filters at the tank and carb end. Link to comment Share on other sites More sharing options...
Junkman Posted March 11, 2014 Share Posted March 11, 2014 Bring me 'retter. chaseracer 1 Link to comment Share on other sites More sharing options...
seth Posted March 11, 2014 Share Posted March 11, 2014 Has it still got the original type mechanical pump? I don't see how this could be overfueling, especially if it is the same one as was fitted when the car was last in use. If anything they get worse with age and pump less efficiently, which would not result in overpowering the carb. Only issue could be if it has been off the engine and has been refitted without a spacer if one should be there? The Brookhouse site seems to suggest there should be. My vote is still with the carb needle valve. Was it replaced? Or the new float is faulty. Link to comment Share on other sites More sharing options...
dugong Posted March 11, 2014 Author Share Posted March 11, 2014 My vote is still with the carb needle valve. Was it replaced? Or the new float is faulty. Yes, it was replaced with a new one that kept sticking and leaked fuel. The old one that was also cleaned in the rebuild was refitted because the needle didn't stick and, er, that fuel farting extravaganza resulted. It's running a mechanical fuel pump. Link to comment Share on other sites More sharing options...
outlaw118 Posted March 12, 2014 Share Posted March 12, 2014 I don't want to see that photo evar again. Pete-M 1 Link to comment Share on other sites More sharing options...
Inspector Morose Posted March 12, 2014 Share Posted March 12, 2014 Am I right in assuming the fuel is pissing out from the top gasket where the fuel bowl is? If so, then thinking it through, the fuel is being supplied by the mechanical fuel pump at a rate that varies but should be enough for it to supply too much fuel for the carb and engine to use. As there is no return system that I know of, the only thing that stops the fuel just overflowing out can only be the needle valve,pushed by the float. Now as the bits have been changed for good ones and assuming that they are working, do we know if the float is closing the valve properly and at the right time i.e when there is just the right amount of fuel in the bowl, roughly just above three quarters full as a very rough guide. How does the float operate the valve? Is it just resting on, in that case is there a dent or even is it the right shape. If the valve is closed by a separate flap type lever, has it been knocked or slightly bent out of shape? Just a thought. I'm pissed and tired so I'll look it up properly after a few hours kip. dugong 1 Link to comment Share on other sites More sharing options...
jonathan_dyane Posted March 12, 2014 Share Posted March 12, 2014 I'd be surprised if an original mechanical fuel pump can overpower the needle valve and would suspect either sticking bent or incorrectly set float or shit in the needle valve which despite all the cleaning I would consider suspect number 1. Strip check and clean... Link to comment Share on other sites More sharing options...
Inspector Morose Posted March 12, 2014 Share Posted March 12, 2014 No it can't but the pump will supply just a bit too much fuel and it's the needle valves job to stem the excess flow. In other words we agree! Link to comment Share on other sites More sharing options...
Junkman Posted March 12, 2014 Share Posted March 12, 2014 I want that carburetter on my kitchen table.No carburetter has ever won against me and so won't this one. Rusty_Rocket, Inspector Morose, chaseracer and 2 others 5 Link to comment Share on other sites More sharing options...
michael1703 Posted March 12, 2014 Share Posted March 12, 2014 Float height too high? Has it got its little brass flap on top of the float chamber? Looks like this I own two vans which have the same carb and never had that problem despite my gasket being made of an insole of an old boot I've got some spare carbs if you need spares, mine are ford Thames 400e but they are the same also consul and zephyr 1703cc 204e 211e engines have them Link to comment Share on other sites More sharing options...
michael1703 Posted March 12, 2014 Share Posted March 12, 2014 Going back to detritus... I've got a mk10 jag, its always sucking up shite from somewhere even though I cleaned and rodded the tank out It has a filter on the tank pick up,each leccy fuel pump has a filter built in, it then gets pumped to the sediment bowl on the osf inner wing which has a gauze filter, it then goes through an aftermarket inline filter and then splits in to 3 to feed each carb which each in turn have an inbuilt filter AND IT STILL GETS SHIT IN THE CARB! AAARRGGHH Sorry,got sidetracked Link to comment Share on other sites More sharing options...
derskine Posted March 12, 2014 Share Posted March 12, 2014 Float height too high? Has it got its little brass flap on top of the float chamber? Looks like this I own two vans which have the same carb and never had that problem despite my gasket being made of an insole of an old boot I've got some spare carbs if you need spares, mine are ford Thames 400e but they are the same also consul and zephyr 1703cc 204e 211e engines have them Make sure this thing is the right way up, I had a similar problem on my Zenith carb, which looks almost the same as that one, and someone had put that in upside down so the needle was open when the float was as high as it could go. Pete-M 1 Link to comment Share on other sites More sharing options...
Sloth in a bowl Posted March 12, 2014 Share Posted March 12, 2014 It will be the needle and valve at the top of the float chamber. I had this grief on the datsun for ages till I got new parts which given the only supply in the world for Hitachi carbs is in the US bumraped my wallet. So is your needle/valve proper original new, secondhand new or cheap copy new? Also if you are twin carbed, make sure that you have the correct needle valve in the right carb, often one is longer than other as one float chamber is in front of the carb and the other is behind the carb. This is to take acount of fuel surge under acceleration. Link to comment Share on other sites More sharing options...
nigel bickle Posted March 12, 2014 Share Posted March 12, 2014 Shit in the carb. Its really common in long term lay ups -and follow all the symptoms described. it'll take several disposable filters, close to the carb and about 500 miles (2 tanks full) before you can be confident its cleared. You've a 50/50 on a temporary repair with a gentle hammer tap to the side of the carb -which may dislodge the shit. Carry tools- you're going to need them for at least a few weeks. catsinthewelder 1 Link to comment Share on other sites More sharing options...
Jim Bell Posted March 12, 2014 Share Posted March 12, 2014 Shit in the carb. . I cannot imagine how that would help, but I would like to see pics of this for research purposes. Junkman, Bobthebeard, dugong and 4 others 7 Link to comment Share on other sites More sharing options...
Sigmund Fraud Posted March 12, 2014 Share Posted March 12, 2014 Float height too high? Has it got its little brass flap on top of the float chamber? Agreed ! I know little about Zeniths, but I've had a couple of old Webers give similar problems to what you describe if the float was not adjusted correctly. Link to comment Share on other sites More sharing options...
M'coli Posted March 12, 2014 Share Posted March 12, 2014 With the beauty of modern technology, somehow a camera and an LED flashlight can be mounted/taped in an engine bay so that this sort of leakage can be filmed over a variety of engine speeds, and the cause of the problem can be narrowed down quite quickly. Link to comment Share on other sites More sharing options...
dugong Posted March 12, 2014 Author Share Posted March 12, 2014 Shit in the carb. Its really common in long term lay ups -and follow all the symptoms described. it'll take several disposable filters, close to the carb and about 500 miles (2 tanks full) before you can be confident its cleared. You've a 50/50 on a temporary repair with a gentle hammer tap to the side of the carb -which may dislodge the shit. Carry tools- you're going to need them for at least a few weeks. A tenner to the man from Sussex. The very kind gent from the VOC came back today to have a look - and there's a lot of shit ending up in the float valve, causing it to stick. It must be coming from the dregs in the tank because the lines are all new. New-old float valve cleaned thoroughly, fuel ingress thoroughly blasted through. There's a pump-side filter installed now. It probably won't be the last one. The float level and tab were also checked. VOC gent also brought along his 'possibly used by AMC' pressure meter to see what the pump was chucking out ; according the workshop manual the maximum permitted flow was 2.5lb at pump height - mine's chucking out 4. Apparently, this was 'about average' according to VOC bod and nothing to worry about even though it's nearly double what the book recommends. If by three tanks and filters the float valve's still sticking, I'll admit defeat and change the fuel pump. trigger 1 Link to comment Share on other sites More sharing options...
Volksy Posted March 13, 2014 Share Posted March 13, 2014 Could this be useful to you? http://www.ebay.co.uk/itm/1966-Volvo-122S-1780cc-BREAKING-/360651598271?pt=Automobiles_UK&hash=item53f882a9bf Link to comment Share on other sites More sharing options...
nigel bickle Posted March 13, 2014 Share Posted March 13, 2014 Jon, it'll keep happening. Learn the process for roadside dismantling, jet cleaning etc. 15 mins aggravation, sorted. Its virtually a given these days, when any carb'd monster has been ''off road'' for more than 6 months. Spend the tenner on strong ale, lad! Junkman 1 Link to comment Share on other sites More sharing options...
Angrydicky Posted March 13, 2014 Share Posted March 13, 2014 Yep, have had this problem (sediment in the tank, that finds its way through to the carb) on many a car, quite often with Zenith carbs too. If the car starts misfiring soon after purchase, first thing I do now is whip the top off the float chamber and have a look inside. Nine times out of ten it's full of crud. The Somerset started doing this, I mentioned to the previous owner I was going to fit an inline fuel filter and he advised that I didn't bother because the brand new genuine SU fuel pump he fitted had a filter inside. He was wrong, fuel pump and tank filters simply don't filter out this shit. One car I had already had an inline filter fitted under the drivers floor, which I didn't know about, and it was clogged. I got very adept at stripping down the carb by the roadside and blowing through the jets! You may get lucky, and find it only needs one or two filters before it's all cleaned out of the tank, but I did have a car once that took at least 10, I had to change them once a week before it was clear. On really long term layups I have found the crud can actually block the pickup pipe in the tank and it's often worth removing the tank to give it a swill out. Although it's unlikely your Amazon will need this as relatively speaking, it hasn't been off the road that long and has been running well with no fuel flow problems. Keep an eye on the new inline filter, and change it once it fills with dirt. Link to comment Share on other sites More sharing options...
dugong Posted March 13, 2014 Author Share Posted March 13, 2014 Could this be useful to you? http://www.ebay.co.uk/itm/1966-Volvo-122S-1780cc-BREAKING-/360651598271?pt=Automobiles_UK&hash=item53f882a9bf I............may have to go and look at that. Link to comment Share on other sites More sharing options...
Station Posted March 13, 2014 Share Posted March 13, 2014 Dodgy carb can be the death of a car. Give it to a specialist and never mess with it as you'll end up hating the car.Then realise no-one actually services carbs anymore, and then let car languish in garage for 10 years because of a shitty, outdated piece of shit (the carb). I know one thing is that the reasons carbs don't work aren't always the same why fuel injection doesn't work - check the gaskets are OK and it's all tightened down.Wish I could offer help, but the only thing owning carb'd cars has taught me is that they're mostly shit and never work. Link to comment Share on other sites More sharing options...
Junkman Posted March 13, 2014 Share Posted March 13, 2014 Spend the tenner on strong ale, lad! Wiser words were never written. I............may have to go and look at that.When? Link to comment Share on other sites More sharing options...
michael1703 Posted March 13, 2014 Share Posted March 13, 2014 with a zenith vn carb, keep 2p on you at all times because you can unscrew the float bowl with it when it picks up muck Link to comment Share on other sites More sharing options...
Conrad D. Conelrad Posted March 13, 2014 Share Posted March 13, 2014 Jon, it'll keep happening. Learn the process for roadside dismantling, jet cleaning etc. 15 mins aggravation, sorted. Its virtually a given these days, when any carb'd monster has been ''off road'' for more than 6 months. Spend the tenner on strong ale, lad! True. Mini used to suffer a 'failure to proceed' every couple of weeks and it was always down to dirt in the carb. A cheap inline filter as close as possible to the carb sorted it. Seemingly insignificant amounts of crud were completely disabling the car. Link to comment Share on other sites More sharing options...
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