hendrixswhitestrat Posted August 15, 2014 Share Posted August 15, 2014 Shocking week at work, irritating neighbours and now on the eve of the Sandra Harrison Moore blat the car starts playing up Grrrrrrr Parked 3 weeks ago before hols and running fine now misfiring all over the shop, checked and gapped plugs, stuck a new set of HT leads in but to no avail. Car ticks over no problem but as soon as I floor the accelerator pedal the engine coughs and nearly dies before picking up. Drove to the end of the road and back and car very sluggish and missing. Can only think it's carbs ? fuel starvation of some sort ? Any thoughts most welcome ! If it is fuel anyone know a good mobile mechanic around Guildford who can sort out the webers ? Cheers all.....off to bed before anything else happens :-/ Link to comment Share on other sites More sharing options...
hendrixswhitestrat Posted August 15, 2014 Author Share Posted August 15, 2014 Sorry...car is a 1990 year 1700 Xflow with twin webers and twin chokes HWS Link to comment Share on other sites More sharing options...
Paul Deslandes Posted August 15, 2014 Share Posted August 15, 2014 When it picks up after blipping does it rev ok? My first port of call would be to check that the floats/needle valves are working correctly as, what you have sounds like lack of fuel in one or both carbs. Is the pump ticking normally? I assume you have a Facet solid state pump. Do you have an in-line fuel pressure regulator? I don't know the ignition setup on the X flow. Does it have points/condenser or electronic ignition of some sort? They can also give similar symptoms. Link to comment Share on other sites More sharing options...
hendrixswhitestrat Posted August 15, 2014 Author Share Posted August 15, 2014 Hi Paul thanks for posting - yes it revs okay after pick up (if a little lumpy) - agree that it sounds like fuel in one/both cabs - yep pumps seems okay - not sure about inline pressure reg - my car has electro ignition webers were really popping, banging and spitting so I'm fairly sure it's something to do with them Link to comment Share on other sites More sharing options...
Paul Deslandes Posted August 15, 2014 Share Posted August 15, 2014 1. when you took the old plugs out were they black and sooty, white and very clean or nice brown colour? 2. when it's running does it smell very rich? 3. is there any evidence of fuel running out anywhere, e.g. smell of petrol, visible signs around one or other carb? Link to comment Share on other sites More sharing options...
hendrixswhitestrat Posted August 15, 2014 Author Share Posted August 15, 2014 Hi Paul 1. Plugs very black and sooty (fuel mix too rich) 2. Yes it has done of late (but was running okay) 3.Nope but carbs smell very strongly Link to comment Share on other sites More sharing options...
Paul Deslandes Posted August 15, 2014 Share Posted August 15, 2014 I'm not a particular advocate of whacking things and seeing what happens 😬 but, on the basis that this is possibly a needle valve stuck open or nearly shut, you could try giving each carb a sharp tap towards the rear as this might free the needle valve if it is stuck. Link to comment Share on other sites More sharing options...
hendrixswhitestrat Posted August 15, 2014 Author Share Posted August 15, 2014 LOL Have tried giving them a gentle tap with the heel of my hand but no joy.....think they probably need stripping down and balancing ? Link to comment Share on other sites More sharing options...
Paul Deslandes Posted August 15, 2014 Share Posted August 15, 2014 sounds as though this has been building up for a while and one of the carb levels is too high. Where abouts are you? I'm at Gomshall just off A25. Any chance you could get it over here as I'd be happy to have a look, having a had a few webers apart over the years. Link to comment Share on other sites More sharing options...
Paul Deslandes Posted August 15, 2014 Share Posted August 15, 2014 another possibility is that one of the choke lever/fuel enrichment device has operated. These cause havoc if they're not properly in the off position. Assuming your carbs have them, and not all do, have a look at the back of the carbs and make sure that they're both 'off'. Edited by - Paul Deslandes on 15 Aug 2014 14:34:54 Link to comment Share on other sites More sharing options...
hendrixswhitestrat Posted August 15, 2014 Author Share Posted August 15, 2014 Hi Paul I'm in Godalming...are you sure ? Would be great to make the run tomorrow my number is 07971 627717 Link to comment Share on other sites More sharing options...
Myles Posted August 15, 2014 Share Posted August 15, 2014 FWIW (maybe not much), my k-series idled horribly when I first fired it up this year - and when I took it out on its first test run, it was lumpy, couldn't take throttle, misfired and generally had to be coaxed down the road. The problem turned out to be water ingress into the spark-plug wells over winter - with associated corrosion of the spark plug outer contacts, ht lead sockets etc. Obviously this isn't exactly what you have - but it strikes me that the symptoms as described could still be electrical in nature even given that you have fettle the plugs and replaced the HT leads. For my money I'd make sure that it wasn't electron-related before faffing with mechanical bits. Link to comment Share on other sites More sharing options...
Roger King Posted August 15, 2014 Share Posted August 15, 2014 If the engine is running OK on constant throttle, be it at idle or when driving, but won't pick up during transients (when you're opening the throttle), it sounds like the throttle pumps may not be working. Air has lower mass than fuel, which means that as you depress the throttle the extra air now admitted to the engine "gets going" more rapidly than the extra fuel that is sucked in through the carburettor. What this means in practice is that you go through a short period where the mixture is far too weak and the engine runs badly. Engines also like to be a little richer than normal during this period anyway, which just makes things worse. To compensate, carburettors have a throttle pump. This is really just a crude fuel injector that manually squirts a little extra fuel in as you open the throttle; the exact amount being determined by the size of the pump jet, the air bleed circuit and the stroke of the pump. In practice you can easily see if this is working by removing the air filters, shining a torch down the carburettor barrel and opening the throttle by hand (engine not running) as you look at the butterfly. If working, you will see a small trickle of fuel running down the butterfly each time you open the throttle a bit. You need to check all four barrels to make sure that all are working. If it is working, you need to look elsewhere. If not, you need to check the pump jets are not blocked and that the mechanism isn't seized. When you fire the engine from cold and give the throttle a few pumps you are actually squirting fuel in from the pump jets to provide a measure of cold start enrichment. Edited by - Roger King on 15 Aug 2014 17:46:30 Link to comment Share on other sites More sharing options...
Paul Deslandes Posted August 15, 2014 Share Posted August 15, 2014 Hi Roger, I was hoping you'd pop up. Martin brought the car over and we've improved things a bit. The engine was running extremely rich, almost to the point of stalling at idle and virtually undriveable anywhere else, so we checked that the needle valves were set correctly, which they were, and that the the float chambers weren't over filled, which they weren't. As a matter of course we removed all the jets and checked that they were clear, but no change. We eliminated ignition by checking that all the plugs were sparking properly and the compressions on each cylinder were all within 10psi. Martin always uses his choke to start the car and I know from experience that the fuel enrichment devices can stick open. As the car hadn't been run for about three weeks and nothing had been done to the car it was a bit of a puzzle as to what was going on. I operated the choke mechanism back and forth a few times in a fairly spirited fashion and, on restarting and giving it a good blast, it improved significantly and I'm fairly convinced that this is where the problem lies. We didn't have sufficient time to strip and clean the carbs but, for now, hopefully its running well enough for him to use on the blat tomorrow, always assuming he got home alright 😬. A strip down and rebuild is really needed to get them right though. Link to comment Share on other sites More sharing options...
hendrixswhitestrat Posted August 15, 2014 Author Share Posted August 15, 2014 Hello gents....thanks for posting Roger, much appreciated, and Paul - what can I say you are an absolute gent ! Just got back from putting the car away it ran really well, popping and bangs have gone and it is more responsive than it has been for a while ! Can't thank you enough really - red wine on the way !!!! *thumbup* *thumbup* *thumbup* *thumbup* *thumbup* *thumbup* 😬 😬 😬 😬 😬 Link to comment Share on other sites More sharing options...
hendrixswhitestrat Posted August 15, 2014 Author Share Posted August 15, 2014 ....and am having Webers overhauled after tomorrow ! Cheers guys. HWS Link to comment Share on other sites More sharing options...
nickh7 Posted August 15, 2014 Share Posted August 15, 2014 What a club , its just so good to have this shared community Enjoy your healthier 7 Link to comment Share on other sites More sharing options...
Paul Deslandes Posted August 15, 2014 Share Posted August 15, 2014 You're very welcome and I'm delighted that you'll be able to get your blat tomorrow. Paul Link to comment Share on other sites More sharing options...
john g Posted August 15, 2014 Share Posted August 15, 2014 Yeah, the members who share their knowledge and expertise is super. I had an issue with my xflow just before we went to the LMC and the members on here directed me to the solution. Link to comment Share on other sites More sharing options...
Baz Hemsley Posted August 15, 2014 Share Posted August 15, 2014 www.Airey Tuning.com at Cheriton. is the man to sort your carbs out. Can have a chat tomorrow. He did mine. I wish I'd had it done yrs. ago. Link to comment Share on other sites More sharing options...
hendrixswhitestrat Posted August 15, 2014 Author Share Posted August 15, 2014 Cheers Baz....be great to say hello tomorrow...I'm in the red H reg xflow with a picture of Hendrix on the back Link to comment Share on other sites More sharing options...
Roger King Posted August 16, 2014 Share Posted August 16, 2014 This saga shows that you should NEVER connect the cold start device (it's not a choke, but an over-enrichment circuit). I've never known them give anything but trouble and they are completely superfluous. If the engine is healthy and correctly jetted, a few pumps on the throttle before cranking is all that you need to start. Link to comment Share on other sites More sharing options...
Paul Deslandes Posted August 16, 2014 Share Posted August 16, 2014 Amen to that Roger I've seen several where the device has been disconnected and the drillings blanked off. Link to comment Share on other sites More sharing options...
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