van won't start

[FrankM83]

Hi all, tried starting the van today but the engine kept turning and turning, fuel pump is ticking but it won't start any ideas please? :S

[billlobban]

Firstly check you are geting a spark at the plugs then work your way back from their

[mike.perry]

Check the electrics. Are the plugs sparking?
Is it a new engine, if so check that the HT leads are in the correct order and that the timing is not 180deg out.

[PSL184]

All you need is fuel, compresson and a spark (the spark needs to be in the correct place at the correct time). If you have all 3 she will run so check that the pump is pumping by taking the pipe off the carb and pump fuel into a glass jar. Also you can take out a plug after it has been turned over and see if it smells of fuel. Take the plugs out one at a time and connect to the relevant HT lead. Lay plug against the block and see if you get a good strong spark from each one. Then check the leads are in the correct order. 1,3,4,2 anticlockwise around the dizzy cap. If all that fails come back for some more suggestions

[FrankM83]

ok here's my stupid question, how do you check they are 1,3,4,2? is it written onthe cap or what? :S

[PSL184]

Assuming the engine is timed correctly, remove No1 spark plug. Put a thin piece of wood (or a screwdriver very gently) doen the plug hole and turn engine until No1 cylinder is at the top.(you wil know it is at the top when the piece of wod rises up fully). Take off dizzy cap and look at the position of the rotor arm. It should be about the 7 O Clock position if looking from the side. The lead that is connected to this point on the dizzy is No1 and will go to No1 plug. Moving round the dizzy anticlockwise the next lead should go to No3 plug, the next to No4 plug and the last one to No2 plug

[FrankM83]

Thanks for the explanation, really helpful, what's confusing me is that the engine sometimes starts but very tired and fainted and wants to go off again, but today it just wouldn't start :S for some reason im blaming the carb but it has been rebuilt, reall really confusing

[PSL184]

Sounds like a fuel issue for sure, but, have you checked all the ignition componants, plugs, leads, coil, points, condensor etc....?

[bmcecosse]

That method of finding the correct firing point for #1 has only a 50% chance of success! You need to know it's on the COMPRESSION stroke - so either put thumb over spark plug hole and feel the pressure - or take rocker cover off and see the valves on #4 'rocking' at TDC - then you KNOW #1 is ready to fire. It's not just ancient fuel in the tank ? In your hot weather fuel won't last long. Tip some fresh stuff down the carb inlet - and crank it.

[PSL184]

That is correct which was why I clarified "assuming the timing is correct" and "the rotor arm should be around the 7 O Clock position". Frank wanted to ensure his leads were in the correct order and not time the engine from scratch. If you were not on the compression stroke the rotor arm would be more around 1 O Clock.....
Goos point about fuel though - I was most disappointed with the performance of a car I drove recently until I found out that the fuel in the tank was about 3 years old !! I did run - but only just

[bmcecosse]

Rotor arm could be pointing anywhere! It's not important where - but what is important is that it points to #1 plug lead connection (at any o'clock) when #1 is at TDC on the compression stroke.

[FrankM83]

well problem was,,,,,, my mechanic replaced my carb with another carb I had running in the garage as the carb we rbeuilt was giving problems ( engine kept running rich!! no matter what setting we gave it) the carb I gave him, he just fitted it as it was and the van worked perfect but during it's time lying in the garage grunge jammed the "piston" that's y it didn't start, dismantled the carb and cleaned it, now everything is fine

2nd problem:- why is a freshley rebuilt carb giving me problem like staying too rich?? even tho we tried setting that screw thing? my mechanic mentioned a worn inner needle?

[bmcecosse]

The needles rarely wear - the jet - into which the needle fits, can become slightly oval rather than round - but this can usually be adjusted out. Most likely is that the fuel level is too high - either because the float is holed (or just set too high) - or because the little needle valve that meters the fuel into the float chamber from the pump - is leaking!

[autolycus]

2nd problem:- why is a freshley rebuilt carb giving me problem like staying too rich?? even tho we tried setting that screw thing? my mechanic mentioned a worn inner needle?

"that screw thing" isn't a Morris standard part description. The mixture is adjusted by means of the jet adjusting nut, under the carburettor, so if you tried fiddling with screws, it's no wonder you had problems.

A common fault if carburettors have been stripped by those unfamiliar with SU carbs is for the needle to be pushed too far into its hole. The Book of Words shows the use of a straight edge to ensure the shoulder on the needle is flush with the piston base. Might be worth checking that the correct needle has been fitted - their designation is engraved on the shank.

Kevin

[FrankM83]

Thanks for your explanation, it's a big mystery we have rebuilt 3 carbs and all gave the same problem,mixture is too rich! then I fitted one off the shelf without touching it and it's perfect is there a book which shows which needles go with which carbs etc please? my mechanic used to build Minis for hill climbs! so I think he knows SUs a bit, thanks for all the help and advise

[mogbob]

Frank
The SU Reference Catalogue available from Burlen Fuel Systems Ltd 01722 412500 is one source but there are others like
Haynes SU Carburettors ( available from various sources )for instance.
Bob

[bmcecosse]

This link to SU carb information is very useful - a bit dated - but fine for Minor SUs! http://www.sterlingbritishmotoringsocie ... _Carbs.pdf