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trouble with Lanchester cutting out.
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Lanchester 1953



Joined: 05 May 2016
Posts: 34

PostPosted: Thu May 05, 2016 6:44 pm    Post subject: trouble with Lanchester cutting out. Reply with quote

Hello, I am a new member, just got a Lanchester 14. Out today and it would not go above 40, cut out a lot , but perfect tickover, only when I opened the throttle was there trouble. I am now cleaning the carb , and next will be the fuel pump filter bowl. What actually is the Zenith model on the 14? ( so I can get a gasket set for it). apart from this , it runs well. Box is OK and brakes OK for that year I suppose. Totally unrestored and I will keep it that way.
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Farmer John



Joined: 18 Feb 2010
Posts: 172
Location: Manawatu NZ

PostPosted: Thu May 05, 2016 9:30 pm    Post subject: Lanchester Reply with quote

Hi. I have a 1953 Leda, it is an export model being in NZ, so there are differences.
When removing the carb float chamber empty the contents into the palm of your hand to check for water droplets. If there is water it will recontaminate the system continually unless the tank is cleaned. The petrol we buy now seems to leave residues that can only be removed by carb cleaner so use that even if your petrol is OK. Check every orifice, every drilling, every jet. I know that it is not recommended but use fuse wire to check all passages and be very, very, gentle. Flush it all through with carb cleaner (use safety specs) blow with compressed air and then repeat the treatment.
Test the fuel pump by disconnecting the pipe frpm the carb and winding the motor over on the starter. Use a bottle or large container to catch the petrol, you should get spurts of a solid stream that will go somewhere around 300mm. On first dismantling the pump look for water. No need to worry too much about what sort of debris there is in the pump, it might not have been cleaned for years. Clean same as the carb but do not dismantle just remove the bowl.
The most telling test of a fuel pump is a vacuum gauge on the inlet side. The reading is not as important as the ability to hold vacuum, so wind the engine over until maximum vacuum is reached and then watch the needle.
You should not be able to see it move. If you go and make a coffee it will fall to zero but that does not matter.
Almost forgot, whenever investigating a fuel system leave the hand primer alone! If the engine will not wind over attend to that problem, do not use the primer.
My car has a reserve system with a control on the dash. Do you have that? If so set it to reserve for the purposes of all this testing.
Remove the filler cap and use compressed air to blow out the line from the pump to the tank while someone listens at the filler, ear to one side in case petrol gushes out, bubbling in the tank tells you the pipe is clear. Set the reserve tap to normal, reconnect the pipes.
Use the starter in ten second bursts to restart the car, if there is an assistant around put the fuel pipe to the carb into a bottle to make sure the system is working again then reconnect to the carb as soon as petrol appears and continue starting.
Do not worry about cleaning the tank for now, that is a whole other matter.
Do report back.
John
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Lanchester 1953



Joined: 05 May 2016
Posts: 34

PostPosted: Thu May 05, 2016 10:48 pm    Post subject: Lanchester Reply with quote

Thanks, I have already cleaned out the carb bowl. removed the jets and cleaned the lot with tinners and carb cleaner. I tested the fuel flow with the starter and have a good flow, I will also put a newish flat needle valve in tomorrow. I could buy a set of gaskets etc but I don't know the number of the carb, it isn't on the body as far as I can see.
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kevin2306



Joined: 01 Jul 2013
Posts: 1331
Location: nr Llangollen, north wales

PostPosted: Fri May 06, 2016 10:52 am    Post subject: Reply with quote

I wonder if the issue is more with electrics.
I used to race a Triumph motorcycle with magneto ignition, after a while, the spark wasnt as good as it should be so was effectively being drowned by the fuel. sorted the ignition side out with a rebuild and all was well.

Kevin
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petelang



Joined: 21 May 2009
Posts: 261
Location: Nottingham

PostPosted: Fri May 06, 2016 3:22 pm    Post subject: Reply with quote

I recently had a similar occurrence on my Daimler Fifteen, which I put down to a dodgy condenser. Points had a big blob of clag stuck on them which caused erratic running, fine one minute, running very lumpy the next. The condenser hadn't been on so long and it was difficult to find as the points gap looked good but the offending clag was hanging on the underside of the contact so hard to see.
New condenser and points fitted and it's now absolutely fine.
I identified this as the problem after flicking the points open when it gave up and stalled on the road, testing for a coil spark. There was no little spark at the points. Having opened the points with a screwdriver to a wider gap I then got a spark.
Do let us know how you get on with a solution.
Peter
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Lanchester 1953



Joined: 05 May 2016
Posts: 34

PostPosted: Fri May 06, 2016 6:41 pm    Post subject: Reply with quote

the problem was not electric, all the leads and plugs etc are new, I stripped the carb, cleaned the jets and found TWO washers under the needle valve! I also advanced the ignition, (so far no pinking) and now it doesn't cut out, runs and starts well, I had it up to fifty. Seemed to improve during the short journey. Thank goodness the pump was OK, I have no idea where to get one, or a valve renewal kit .
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Farmer John



Joined: 18 Feb 2010
Posts: 172
Location: Manawatu NZ

PostPosted: Sat May 07, 2016 6:29 am    Post subject: Lancester Reply with quote

I have checked in my little old book, it says you should have a Zenith 36VIS The number on mine is on the lower casting, just above the manifold, facing the driver. There is a UK site "zenithcarb.co.uk" but I cannot get in. The serial number is cast into that piece, I looked all over for something stamped!
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Lanchester 1953



Joined: 05 May 2016
Posts: 34

PostPosted: Sun May 08, 2016 7:20 pm    Post subject: Reply with quote

petelang wrote:
I recently had a similar occurrence on my Daimler Fifteen, which I put down to a dodgy condenser. Points had a big blob of clag stuck on them which caused erratic running, fine one minute, running very lumpy the next. The condenser hadn't been on so long and it was difficult to find as the points gap looked good but the offending clag was hanging on the underside of the contact so hard to see.
New condenser and points fitted and it's now absolutely fine.
I identified this as the problem after flicking the points open when it gave up and stalled on the road, testing for a coil spark. There was no little spark at the points. Having opened the points with a screwdriver to a wider gap I then got a spark.
Do let us know how you get on with a solution.
Peter
Now after another breakdown, seems that the points are faulty - too far worn so . I will replace them --- the points, condenser, coil as well. Also I will get a new "economy valve" - these always play up when a bit old.
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norustplease



Joined: 11 Apr 2011
Posts: 620
Location: Lancashire

PostPosted: Mon May 09, 2016 11:26 am    Post subject: Reply with quote

I have an occasional issue with my Traction which sounds very similar. I started out with a carburettor strip down, since I also had some cold start issues, and found the system full of sediment. This is obviously caused by 62 years worth of dirt in the fuel tank. Having originally found this, I now have a disposable filter fitted upstream of the electric fuel pump, which periodically partially blocks up ( the fuel in the transparent body goes the colour of milky tea). I assume therefore that when the filter partly clogs, the flow is insufficient to support anything beyond tickover and in extremis, the back pressure may also be sufficient to make the SU pump think that the float chamber is full, and it ceases working. Changing the filter fixes the problem, sometimes giving it a vigorous shake is sufficient to reduce any blockage as a get you home measure. The real cure will be taking out the tank and cleaning it out, which is on my list for Autumn. At the moment, however, I get by, changing the filter at intervals, particularly before a more ambitious trip.
I have a friend also with a Traction, who has had similar symptoms from a mechanical fuel pump failing to deliver sufficient fuel to drive the car properly.
_________________
1953 Citroen Traction
1964 Volvo PV544
1986 Renault 4
1990 Citroen 2CV
Boring Fiat 500X
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