Bob_Rich Posted September 11 Share Posted September 11 My Lotus seven ( 1969 series 3 with sprint spec crossflow ( by late Steve Parker) ) had stood with very little use over the last year ( tank full with E5) but was kept in the garage. It proved difficult to start so as battery was new and I thought I had some issues with the timing ( but the was not the case) but basically at tick over it was OK checked the tappets and fitted new plugs. changed the fuel filter on the Facet fuel pump. I have had the 40DCOE's cleaned by Chelmsford Weber services and initilally the car started and ran OK which was encouraging however it cut out while out for a blat and although I got it going it became more difficult to start and finally it wouldn't. This is when I looked at the fuel tank and it was VERY badly rusted --so I decided to replace the tank with a new alluminium one. Basically the fuel was badly discoloured and the old steel tank was VERY rusty. The colour of the fuel I took out was very different ( brownish) compared to the new stuff I put in the new tank. Things I have checked to get where I am at now (1) new plugs, (2) sparks at all 4 plugs will jump a 6mm gap of my tester, (3) fuel pump delivers around I litre/minute free flow and stalled pressure around 2psi , what it appears to me is that after endless cranking of the motor there is no sign of life. On removing the plugs they don't appear wet and dont smell of fuel. I removed the top overs of the carbs and checked that the floats and the needle valve would let fuel through OK. The fuel in the carbs float chambers looked decidedly brownish(see picture) so using a syringe I sucked it all out and it does look murky compared to the new stuff. reassembled the carbs and heard the fuel pump rang faster ( refilling the float chambers) tried to start it no go. checked the plugs --to me they dont smell of petrol and they look like they have just come out of the box. So I am looking for a bit of advice / help in what to try next -- I am sure it is do with the carbs --I wish I had known how bad the fuel was before I had the carbs cleaned! thanks in advance if you can offer any help / advise Link to comment Share on other sites More sharing options...
OldAndrewE Posted September 11 Share Posted September 11 The first thought is that there is now some crud somewhere in the carbs that is stopping fuel delivery to the engine. If you operate the throttle do the pump jets spray fuel? 1 Link to comment Share on other sites More sharing options...
Area Representative Andrew Gilbert Posted September 11 Area Representative Share Posted September 11 Blocked jets maybe or a failed pump within the carbs or even a blocked filter where the fuel enters the float chamber? You can have those out easily enough and clean them with liberal amounts of carb cleaner but its unusual to have no fuel getting through. 1 Link to comment Share on other sites More sharing options...
Jonathan Kay Posted September 11 Share Posted September 11 1 Ether spray in the air intake while turning over as a diagnostic test. 2 Fuel filter(s) as above. Plus disconnect at the tank and blow compressed air through backwards. Jonathan 1 Link to comment Share on other sites More sharing options...
Bob_Rich Posted September 12 Author Share Posted September 12 Hi all well I have got the carbs off and when tested on the bench only the 4th pot produces a squirt of petrol when you operate the throttle. So I have got some carb cleaner and going to have a good clean of it following advice from Paul at Chelmsford Weber Services. With the top cover off there is still some dirty fuel in the float chamber. Not to keen on using Ether because up to now no fuel has been coming through, The fuel from the new tank is clear and clean flushed It through with the fuel line off the cabs and into a contained-it was all nice and normal looking . Am going to blow out the jets on the carbs now they are on the bench and thoroughly clean them --again Thank for the advise all most welcome bob Link to comment Share on other sites More sharing options...
anthony1956 Posted September 12 Share Posted September 12 "Car won't start" ooh this gives me the horrors... will have a read now... Link to comment Share on other sites More sharing options...
anthony1956 Posted September 12 Share Posted September 12 (edited) 3 hours ago, Bob_Rich said: Am going to blow out the jets on the carbs now and not just the jets... You have a compressor? Good, I was going to say blast everything. Are the float chambers full when you lift the lids? Are the butterflies swivelling? I LIKE the pump jets test, BUT their not working doesn't mean the main jets aren't. That lousy rotten fuel does look like it has clogged everything. Try blowing in reverse too. Yes I've just been there too (Dellortos - very different problems) - I also use me as the blower (i.e. blow through them yourself so you can feel they are clear - indeed start with that as a test), like the float chambers, blow inwards as I lift the float to check it works correctly. Petrol is an acquired taste 😉 Diagram herewith in case it helps. My money is all 4 main jets/emulsion tubes being blocked - take them to bits (mine not Weber are three pieces each, yours are 4 pieces looks like items 10,11,13,15). Idle circuit first. and don't forget all the little "tubes" inside the body of the carb itself. Quote however it cut out while out for a blat and although I got it going it became more difficult to start and finally it wouldn't Yes this screams fuel blockage(s) big time. Given they have been professionally cleaned should mean they are easy to work on (mine are). Amazon say three left, amazon.co.uk makes a change to be offering ideas instead of receiving them (continuously for several weeks!) Edited September 12 by anthonym Link to comment Share on other sites More sharing options...
Gridgway Posted September 12 Share Posted September 12 It's got to be a carb problem. The old fuel crud has got in there. I know you've said you don't like the idea, but you can isolate the problem by spraying easy start or brake cleaner into the intakes. If the engine runs and stops it's a carb problem. If it doesn't run then it's a spark or timing problem. No need to be precious about it. When we start the BDG (overblown cross flow) in my F2 race car, we take a water bottle, make a hole in the lid and fill it with petrol to have a big squirt down each throttle body to get it going! 1 Link to comment Share on other sites More sharing options...
anthony1956 Posted September 13 Share Posted September 13 (edited) 16 hours ago, Gridgway said: I know you've said you don't like the idea, I use "Holts Bradex Easy Start" for this (EDIT: looking for air leaks NOT starting the car) , having said that we concur it's crud jammed in there - guilty admission coming up: a few days ago I had flames everywhere (felt like it) when a nearby cloth caught fire having soaked in some of the fluid and I think it was the spark from an open barrel (no filter) set the airborne product on fire which instantly spread to the cloth (a duster). I stamped it out with my crocs. I keep a fire extinguisher a bit more handy now. So that's me being a terrible warning. I still use the Easy Start, just a bit more warily and no nearby anything combustible. Edited September 13 by anthonym Link to comment Share on other sites More sharing options...
Jonathan Kay Posted September 13 Share Posted September 13 I don't have vast experience of this but I'd much rather use diethyl ether than petrol or acetone. Jonathan Link to comment Share on other sites More sharing options...
anthony1956 Posted September 13 Share Posted September 13 (edited) don't know what Easy Start is..does what it says on the tin tho Edited September 13 by anthonym Link to comment Share on other sites More sharing options...
Jonathan Kay Posted September 13 Share Posted September 13 Bradex Easy Start: https://cdn.aws.toolstation.com/items/coshh/saftey-data-sheet-bradex-easystart-38028.pdf Jonathan Link to comment Share on other sites More sharing options...
anthony1956 Posted September 13 Share Posted September 13 (edited) DIETHYL ETHER, Hydrocarbons, C6, Isoalkanes, <5% n-Hexane, DI-ISOPROPYL ETHER, ACETONE Same page, contents Section 3.2 "much rather use diethyl ether" So you will like Easy Start... Edited September 13 by anthonym Link to comment Share on other sites More sharing options...
Bob_Rich Posted September 15 Author Share Posted September 15 Thanks for all the useful information. Will check ALL the jets and emulsion tubes as well as the starting system. I dont have a compressor. might but I have a mate with one and if I can't clear it I will take a trip to him. Interesting (annoying) week coming Bob Link to comment Share on other sites More sharing options...
anthony1956 Posted September 15 Share Posted September 15 (edited) 3 hours ago, Bob_Rich said: Interesting (annoying) week coming you have my total sympathy - been there for several weeks and compressors are cheap bits of kit and neverendingly useful once you have one - I have an electric one from Aldi, or I did til I broke it (literally) a couple of weeks ago; so bought another also not expensive. This sort of thing (but check details this is just a rough example of amazon.co.uk ) - reason I am pushing a tiny bit is I don't think youll get all that crud out without one at home, having tried blowing through myself, just doesn't cut it. Also good for cleaning grot traps.... Edited September 15 by anthony1956 Link to comment Share on other sites More sharing options...
Gridgway Posted September 15 Share Posted September 15 I can't imagine not having compressed air and tools in my garage if you have space and resources! 1 Link to comment Share on other sites More sharing options...
Bob_Rich Posted September 21 Author Share Posted September 21 Hi Not given up yet ! the general opinion was that compressed air was what was needed. I decided after trying with aerosol air cans not very good so have spent the week making up a simple air reservoir which I can charge up with my higher power air pump ( A 12V 30A device using a twin cylinder compressor) made the reservoir out of a spent helium balloon gas container from my grandsons birthday party. fitted it with a shrader valve and a pressure gauge. It has a test pressure of 25Bar and at 40psi (~3 Bar) hold enough air for quite a good long blast. Got a simple hand tool with a suitable fine nozzle fitment of the web for £5 so good to go! determined to get it going next week!! cheers Bob Link to comment Share on other sites More sharing options...
anthony1956 Posted September 21 Share Posted September 21 I blew mine out with 8 bar... Link to comment Share on other sites More sharing options...
Iamscotticus Posted September 26 Share Posted September 26 E/ Ethanol / alcohol/ blended fuels wreak havoc on aluminum and rubber hoses that aren't resistant to alcohol. I would replace any old rubber fuel hose with Gates Barricade Fuel injection hose, replace any diaphragm fuel pump, and any rubber seals in the carb. And check the carb mounts for air leaks. "The fuel in the carbs float chambers looked decidedly brownish". This should not have even happened, ever. Any old fuel must be completely drained and discarded. Don't ever try to run a car on old fuel. If the car is going to sit for over a month, drain any Ethanol fuel out of everything. Run it with some E-0 (no Ethanol) fuel with stabilizer, then drain that or leave it, your choice. I am not sure If I should believe any fuel stabilizer claims that they prevent ethanol damage. I think they may keep ethanol fuels from decomposing, but I think the alcohol still attacks the elements it is in contact with. Link to comment Share on other sites More sharing options...
aerobod - near CYYC Posted September 26 Share Posted September 26 30 minutes ago, Iamscotticus said: If the car is going to sit for over a month, drain any Ethanol fuel out of everything. Run it with some E-0 (no Ethanol) fuel with stabilizer, then drain that or leave it, your choice. It depends on temperature and humidity on how long the fuel remains fine to use. We have been using E10 fuel here in Canada for more than 20 years now. If stored in a cool environment with fairly constant temperature and low humidity, seasonally used equipment such as lawnmowers and my Caterham have no issues with 6 month old E10 fuel when started in the spring. Link to comment Share on other sites More sharing options...
anthony1956 Posted September 26 Share Posted September 26 (edited) 5 hours ago, aerobod - near CYYC said: We have been using E10 fuel here in Canada for more than 20 years now. If stored in a cool environment with fairly constant temperature and low humidity, seasonally used equipment such as lawnmowers and my Caterham have no issues with 6 month old E10 fuel when started in the spring. Same here in Switzerland at high altitude and freezing over Winter, except I use E5 for the octane.Disconnect the battery and don't touch until May. Edited September 26 by anthony1956 1 Link to comment Share on other sites More sharing options...
SM25T Posted September 26 Share Posted September 26 (edited) Over winter I have put Stabil fuel stabiliser in a full tank and driven it 10 miles before laying up off the road. Edited September 26 by SM25T Link to comment Share on other sites More sharing options...
Bob_Rich Posted September 26 Author Share Posted September 26 Hi and thanks for all the comments Despite using compressed air, liberal amounts of carburetor cleaner, put it all back together. before installing the carbs I checked that operating the throttle I now get 4 squirts of petrol onto the paper for a test and shown in the picture below. Put it back in the car it would still not start. Battery is new and it turns the engine quite quickly in that it does not sound like it is struggling. Regarding the fuel the alloy tank is new and has 15 litres of E5 with STA-BIL in , the hose is suitable for all modern fuels. the plugs are new. I tried ether (Holts Easy Start) and does fire but once that ether is used up it stops. I have twice checked the spark and it looks fine. the plugs are suspisouly clean and don't have a smell of fuel which is what I find odd really struggling but won't give up but would welcome any further advise. bob Link to comment Share on other sites More sharing options...
Jonathan Kay Posted September 26 Share Posted September 26 Thanks for the update and the extra information. What's the fuel pump system? Is the disconnected fuel pipe giving lots of flow during cranking? Can you use that paper test to see what happens with the fuel line connected and the engine cranking? Does it keep squirting? (Or is someone going to tell me that it shouldn't without the suck stroke?) What's the ignition system, and what's the minimum battery voltage during cranking? Jonathan Link to comment Share on other sites More sharing options...
Gridgway Posted September 26 Share Posted September 26 summary seems to be that the engine runs on easy start, but not on the fuel that should be delivered by the carbs. That would seem to eliminate the spark being a problem. It's sparking and sparking at the right times. How many throttle pumps do you give before cranking? Do you pump whilst cranking? Everything still points to a carb problem and fuel not getting through. I see there is a choke mechanism on the carbs - have you used that on cranking? Link to comment Share on other sites More sharing options...
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