it worked before, now it dosent

[cadetchris]

last weekend, i replaced the timing chain with a shinny new duplex one and tweaked the torshon bars inorder to make it ride and sound better.
when i completed this, i sat in it and with a huge grin on my face, turned the key.
nothing, except for a thumb from the general starter motor area every time i turned the key, coupled with the lights on the speedo dimming. coming to the conclusion it was the starter solinoid, i replaced that with a lovely new one. still nothing. next for the starter. having examined the inside and seen it in bits, it was time to replace it.
a nice new one installed and with everything ready to go, i turned the key and again the familliar thump every time the key was turned.

now, this is the point at where i am lost. the battery is fully charged, the wires are all connected and tight and the engine is earthed to the chassis with a steadying bar thingy at the top corner by the heater tap.
after talking to a nice chap at ESM spares, we are both stumped at what the heck it could be stopping the engine from turning over and starting.

anyone have any ideas what it could be?

[cadetchris]

ooh, before i forget, it has a new set of points, condensor and coil as well as a new (3years) wiring loom

[aupickup]

have you checked the braided earth strap from the battery, give it a twist on the fixing point and if it starts now then clean that area of paint to get a good connection

[alzax3]

Well - you've covered a lot of bits.... you say that when you turn the key, you get a thunk and the lights dim, which suggests that the starter is drawing current. If it's not a poor earth/power connection - starting with the obvious: You've changed the timing chain. Does the engine still turn over happily with the handle? IF there's something set up wrong with the valve timing it could be the engine is stuck as the pistons meet the valves. So I'd start there. If it spins over happily, will it start on the handle without using the starter?

[cadetchris]

thats a slight problem, my delightful little brother has lost the handle so i really havent been able to turn it over. i have given it a push and it moves back and forth, but once i have a handle i will give it a good turning over. it if is the pistons, then ill take the chain off and have a head scratch

[littleblackflash]

Agree with the above. Sounds like a mechanical fault as the starter is pulling the current.

Remove the plugs, put it in 4th gear, and then it should roll easily back and forth.

When you finished the timing chain, did the engine turn at all? If it turned 1/2 a rev then try turning it back.

[simmitc]

Take the plugs out. Put car in neutral, handbrake on, ignition off. Be careful of your fingers, but you should now be able to turn the engine over using the fan and fanbelt. It should turn easily. If not, then mechanical problem.

90% certainty that the starter is engaging and then the engine is jamming.

Also, there should be a heavy braided earth connection between rear of gearbox and one of the bolts holding the gearbox cross member to the chassis leg. Without that, you may have electrical problems - the steady bar is just that, with rubber cushions, and is not an earth connection.

Did you use the countersunk retaining bolts that are essential with the duplex chain? If you did not countersink the block then the old bolts will jam the timing gears/chain. If you did countersink, did you get all the swarf out?

[cadetchris]

huzzar, it works now. well ish. but after all that bloody faff, it wont start. could i have upset the timing abit?

[bmcecosse]

The clue is - you fitted DUPLEX !! And when you did this - did you remove the two little bolts going into the front main bearing cap - and countersink the holes - and fit countersunk screws in these holes ?? ??
If not - the chain is jammed against the bolt heads - hence engine not turning. If you have 'forced' the engine to turn by pushing etc - you may well have damaged the chain and/or the sprocket. Strip out and check carefully.

[rayofleamington]

Does the engine still turn over happily with the handle?

to be honest it's very advisable to turn a re-built engine over with the handle before using the starter motor!
Even on modern engines with no starting handle I turn over by hand (e.g. socket on crank or cam sprocket with the plugs out).

could i have upset the timing abit?

if you've not done the timing chain right you could have upset the valve timing a lot!

[bmcecosse]

Well - I see you now say it 'works' ?? But if you didn't do the countersinking - you will have done some damage. It WILL need to be stripped out and fixed.
I had assumed you knew what to do about the timing ? Did you assemble it correctly with dot to dot ?
And sorry -simmitc - I've just noticed you had already mentioned the countersinking! I'm pretty sure that's the problem - we shall see.

[RobThomas]

Timing cover touching the chain? Always the case if you put the breather'd A+ cover over a duplex since there is a nice ring spotwelded onto the inside of the covers with breathers.

Bottom pulley on back-to-front and twisting the chain?

Clutching at straws, now.

[Pikey]

Doesnt really answer your problem, but the engine isnt earthed by the engine steady by the water heater tap.
There should be a heavy looking earthing cable between the gearbox (by the steady wire) and the gearbox cross member. Might explain the possible earthing issues, but not if you havent been anywhere near the cross member and it worked before.

Regards

Steve B

[MarkyB]

The engine steady should have rubber bushes which will insulate the engine from the bodywork both physically and electrically.
The choke cable will act as a poor earth if nothing else is available. It may get hot enough to smoke in extreme cases .

[cadetchris]

all fixed now. the engine wouldnt turn over because two annoying bolts where fouling the chain behing the small lower cog, these have been removed and new counter-sunk screws have been put in there. the engine now moves and starts because i went back and checked the timing, which was abiut 40 degrees out, hence lots of noise but no actual starting of the thing. so i now need to put a new cover gasket on it, replace the heater tap and then in theory it will go.
i fixed the earthing problem by putting and earthing cable from the engine mount bracket on the engine to the bottom of the engine mount coloum thingy, so all is well in yellow morris land

[simmitc]

Good news.

simmitc & bmcecosse remote diagnostics at your service

[bmcecosse]

Hope the chain wasn't damaged !! If it breaks - it will make a fine mess of the engine ! How could timing be 40 degrees out ? Geeeeeeeeeeess.