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MG Midget and Sprite Technical - Not starting

Just got a Mg midget 1873 that has not running for over 30 year, it will now turn over, I have clean fuel at the carbs, I have a strong spark at each plug but it will not fire , why?

ARB Bentley

loads of possible reasons, a bit more info is required as to what you've done so far

how does the starter sound, battery sound, does the engine turn by hand

non-starting on running cars are usually fuel and/or electrics

battery or it's cables and connections and all earths need to be clean, secure and protected

all earth connections need to be clean, secure and protected

fuel - could be carb settings

many things

have you got the Driver's Handbook?
Nigel Atkins

Ignition timing.

Firing order.

Why was it taken off the road?
Dave O'Neill2

I deleted go through a service check, that would cover what Dave has suggested about timing and order - the info is found in the Driver's Handbook

if you can do a video the visuals and sounds will also help - or good clear photos can sometimes highlight problems (but I doubt it in this case but you never know)

be systematic, read the manuals first, start at the beginging of thev process and go one step at a time, look for the bl**ding obvious, (a second set of eyes and ears are useful for this) don't move on to the next step before completing the the present step and don't miss out any steps

always recheck what you 'know' to be OK

Nigel Atkins

"Just got a Mg midget 1873 that has not running for over 30 year, --- "

1873 huh? Well you can't really complain that it's not running too well then. Have you put fire int' hole?
Lawrence Slater

as ARB posted at a quiet time on the forum he's probably got the answer and/or car started by now

does anyone feel brave enough to have a guess at the cause of the non-starting based on their experience of probabilities?
Nigel Atkins

Little or no compression, due to rings seized into pistons?

Timing way out?

Could be a miriad of reasons.
Lawrence Slater

Floats stuck so no fuel? I'd toss a teaspoon of petrol into the carb throat and see if it fires then.
David Billington

Sorry should have said 1973

Ok, the car I have been told was left as a runner all be it 30 years ago, don't really know why it got left but this is a barn find and so a really want to get this car working again, work carried out so far

New battery
Cleaned all earths
Stripped starter, now working fine
New distributor cap
New contact set
New condenser
New rotor arm
New HT leads
New coil

A lot of new parts all in one go, not the way to go but all of the existing hardware was shot

Now have a good spark at each plug, engine cranks over at a good speed and should start

I have good compression I think I don't have a tool to record it but I can feel the compression when I place my thumb over the spark plug hole

Carbs
Full strip down and clean
Replacement of all gaskets
Check of both float valves and floats now working
I am assuming, and this could be the problem that there were setup and working in the first place as I have not changes the needle valve setup.
New fuel pipes have been installed to make sure the fuel getting to the carbs is clean and it is.

Now

With all put back to gather, crank the engender over but it will not fire. An observation, I now take the spark plugs out one at a time and and all plugs are a wash with fuel as if its flooding putting the spark out before it can fire.

I am not at a loss with this. I also have an MGBGT that I have had for many years and I have never got to a point that I have no other ideas as to what is going on.

If anybody can offer some suggestions I would be very willing to try them out.

Thanks in advance


Tony
ARB Bentley

Tony,
thoughts as they arrive in my head

fuel on plugs so they’ll need drying out, petrol washing down cylinders might not help, perhaps dry out and a bit of oiling

carbs settings, including float levels are best checked again

you’ll know not to assume new parts can’t be faulty especially, CB points, condensers and rotor arms

I wonder if it’s a combination of some small failings adding up

as suggested before the timing and mixture need to be near to fire up,
start with checking tappets if not already done so,
then check those nasty CB points are working correctly and installed correctly and insulation bush is in correct position,
check dissy turns freely (oiled dissy and lubed cam)

a though, is dissy in correctly not 180 degrees out

if the engine turns freely then it’s possibly going to be something annoyingly simple so it’ll probably be worth rechecking all as you go along
Nigel Atkins

Tony,

Firing order then? 1342, have you checked?

If the plugs are wet, and there's a good solid spark, and there's decent compression, then my gut says it's a timing related issue. ---- Or a significant air leak?

Does it fire at all?

Dry out the plugs, and leave the choke shut. Try again.
Lawrence Slater

I got to agree with lawerance

Its got to be timming related... remember the dissy turns counter clockwise and the #1 on the cap is about 2 oclock on the dissy as your looking down on it, #2 is about 10 oclock #3 dissy is about 7 oclock, ect.ect.

But a couple ideas to check would be the valves are not sticking. And that you have the engine strap in place from the tranny to the car body

Id also barrow a compression gauge and check the compression at WOT....needs to be around 50 psi minume to fire

EVEN if the cabs are out of adjustment ...if you go a hint of fuel inbthe intake and cly it will fire, and as you said, you have blue flame. And you got prssure on your finger...but how much

So thats my 2 cents...not.enough compression or timing

Prop
Prop and the Blackhole Midget

What about a badly blown head gasket from 30 years ago

Prop
Prop and the Blackhole Midget



Hi

Could you clarify

At the dis

1342

1at 2 o'clock
3 at 10 o'clock
4at 7 o'clock
2at say 4 o'clock


The engine numbering

1 at the rad working back 2 3 4 to gear box

Then

1 goes to 1 and so on

I am now questioning ever thing I do to be sure so sorry for the question

Thanks in advance

Regards

Tony
ARB Bentley

You are correct with numbering.

It's dangerous to assume anything with regard to the position of the distributor on a 39 year old car.

To be sure your sparks are going where they ought to, turn the engine over by hand until No 1 cylinder is at TDC on the firing stroke - i.e. with both valves closed.

Remove the dissy cap and see which way the rotor arm is pointing. Refit the dissy cap and see which lead the rotor arm is pointing to. If it isn't no 1, swap the leads.
Dave O'Neill2

You can't assume that for example number 1 lead will be at 2 o'clock. It is possible to fit the distributor in any number of positions. You have to go back to first principles. Turn the engine over by hand until number 1 cylinder (nearest the rad) is on compression and get the timing marks to be about 10 degrees before TDC. Turn the dissy body until the points are just beginning to open. At that point the rotor arm is pointing towards, or slightly before, the cap terminal that should go to number 1 plug. As the rotor arm travels round ant-clockwise, you can now connect up the other leads anti-clockwise in the order 1, 3, 4, 2. If you aren't sure how to do what I have said, come back.
Mike Howlett



Hi

Can I say many thanks to all, after 30 years and your help its started, ht leads all over the place, lesson for me, don't assume anything

Lots still to do so I am sure I will be back for more help

In the meantime thanks again

Regards

Tony Bentley
ARB Bentley

Congratz Tony,

BY ALL means... Your welcome here anytime, you dont even have to have a mechanical issue stumping you....sometimes we just shoot the brezz talking about our favorite topic... Wheel bearings ...hahahA

Good luck with the next midget project...i hope you can drive her before the snow falls

Prop
Prop and the Blackhole Midget

Tony,
if it had been you looking at someone else's car you have probably checked that quite quickly but when it's your own . . .

you can also check the Archives for info (I put up a thread (Firing order) for these very occasions)

BTW – if you want to you can ‘Customise’ the name and other details that appear at each of your postings and add your vehicle profile with photo, this means others (that check) can see what model and year you have to save a little confusion

oh yes, cigar to Dave and I'll have half a point for 'rechecking'

and - so as not to dissapoint my many fans :)

I recommend, if you've not already done so you buy a copy of the Driver's Handbook


Nigel Atkins

This thread was discussed between 20/10/2012 and 22/10/2012

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