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MG Midget and Sprite Technical - TDC help + dizzy question

Hi all,
midget mk 111.
Midget is failing to start despite having started week or so ago. Plan is to put electronic ( SimonBBC) on board. Looked to find TDC - the pulley has a nice white line on it ....but the timing marks appear to have fallen off.I tried looking down teh rear of teh fan & jacked the car up & looked underneath...no joy.
So - plugs out, put car in gear & rocked it and looked for piston down plug hole. Number 1 piston visible & both rockers on 1 able to rock ( albeit only a little) and with rotor arm pointing towards 1 - which I think is TDC on 1?
Put on an earlier dizzy with an electronic unit ( really for a mini but thought I would try) and put flashers on each plug. No joy- replaced original dizzy with points etc - still no joy.
Any ideas what I am doing wrong- It did run but now wont & i'm loath to put the simonBBC unit on in case I knacker it.
Plain white cable to + - white with black tracer to neg on coil.Battery is good and blasting the starter motor round. I can smell fuel in the block also.
Also, when ( & if ) I get it going again, what should i do about the absent timing marks as I plan to run electronic only.
Really about this but I seem to be going round in circles, and really need any advice!
cheers all
col
colin frowen

You need to find out why you do not have a spark at the plugs this should be easy.

Always try with a dissy that has points. With the dissy in a position where the points are closed and ignition on flick the points open? Do you see a spark across the points?

If not then check that the terminal of the points where he wire connects is correctly assembled and is insulated from earth. (Extremely common fault with enthusiasts who are a liitle confused with electrical systems

A coil can be checked very easily

Place a plug lead into the coil and fit a plug that is reting on the side of the block (earth)

Now the white with black tracer wire needs o be disconnected from the coil and a temporary wire fitted to that connection (marked -ve or CB) flash the other end of this wire against the engine block with the ignition on. This should spark as you touch it against the engine and it should also cause the plug to spark as you touch the wire on and off the block.

See how you get on?
Robert (Bob) Midget Turbo

Hi Turbo Bob
Thanks for your help.
Put the plug lead on block and disc white/ black as you suggested- When using my jump wire got a nice flash from the block & also my spark plug.I guess this means the coil ( & that lead) are ok.
Took out my dizzy & Checked my connections as you said. The LT wire to the dizzy doesnt connect to earth when points are open, but DOES connect to earth when points are closed- have I got this set right?
I will try the dizzy flash thing later today-
sorry to be such a git & really grateful for your help .
cheers col
colin frowen

Reactivating
Dave O'Neill2

This thread was discussed between 19/01/2012 and 08/02/2012

MG Midget and Sprite Technical index

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