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MG MGF Technical - Connecting Ht Leads to the coil

I have just fitted a new set to HT leads to my MGF but forgot to make a note of which numbers go to which coil connections - is there a way to find this out as the car won't start now?

Kris

Kris,

If I recall, the normal convention for the firing order of a 4 cylinder engine is 1,3,4,2.

Sorry I can't be of any more help. I'm sure someone will be along shortly with a comprehensive response.

:-)

Sam
Sam Murray

take out ur number one plug place ur cor in 2 gear place a srewdriver in nuber one plug hole now pull the car foward from front engin crossmember hold the srewdrivr
when the srewdrive reaches its highest point this is top
dead center. ur rotorarm will now be pointing at number one. then pull car forwad again till the rotoarm points 2 the next contact on the dis cap and this will b nuber 3 plug lead. next one will b 4 pluglead ann the last one will b nuber 2. hope this helps.
ronnie

I may be 100% wrong here so please forgive me. Is there not an exaust stroke so when screwdriver gets to top it could be the TDC on exaust rather than ignition ?

In which case the rotor arm would point to another plug to fire ?

How do you tell the exaust from ignition ? I think there used to be mark on flywheel in the old mgs (midget etc ?)

Brian
Brian

You are right Brian. Each piston reaches TDC twice in a 4-stroke cycle, once on ignition and once on exhaust. So if number one is at TDC, it could be about to fire on either number 1 or number 4. But I've a feeling that the K-series uses a "wasted" spark technique, so it fires both 1 & 4 together all the time (and 2 & 3), so maybe it doesn't matter. Will somebody give us the right answer?
Mike Howlett

Some of what I said last night is rubbish. The ordinary (non-VVC) MGF has a rotor arm, so can't fire two plugs at once. So Brian is dead right - with number one at top dead centre, either numbers 1 or 4 might be about to fire. I'm not sure how you can determine which one it is on these new fangled engines.
Mike Howlett

Kris
Number one cylinder is going to fire when its on a compression stroke so if you put your thumb over the plug hole as you push the car in gear with all the plugs out it will push your thumb with the cylinders compression. (Exaust stroke the valve are open)No pressure

Number four is always opposite number one on the distrubter.

Sort 2/3 out the same way.

Let us know how you get on Roger
RJ Rowlinson

I'm not sure this is possible on the F. The plugs are deeply buried in the cylinder head and I don't think you can get your thumb in. It's certainly what I would do on an MGB.
Mike Howlett

This thread was discussed between 10/02/2008 and 04/03/2008

MG MGF Technical index

This thread is from the archive. The Live MG MGF Technical BBS is active now.