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MG Midget and Sprite Technical - Can't get her started....

Hi all

I took my MKII of the road 18months ago to do some major bodywork. I lost my job and some interest so only just getting it finished.
I haven't made any adjustments to anything mechanical or electrical since it last ran. I have put fresh petrol in the tank, and have a filter just before the carbs. I have a spark at all 4 plugs.
When I try to start her she will occasionally fire up but will then die.
When I turn the ignition the pump clicks for a few seconds and then stops as usual. I have fuel at both carbs .

Any ideas on what I can try next?

Tony
Tony Brough

Are you able to do a compression test?

Alternatively, I would take the rocker cover off and turning the engine over slowly, check that none of the valves are sticking open.
Just a thought.
Guy W

Is there enough fresh fuel to make a difference? ie if there was a lot of old fuel and only a little fresh was put in, it would still be doubtful fuel for keen starting.
Is the choke working OK?
Has the fresh fuel reached the carbs? Sorry for stating the bleeding obvious but I am just writing what I am thinking!
JB Anderson

well congrats... your comming along very well, we know its firing, we know its getting fuel...thats Half the battle...I like the idea of a compression check just to round out the tirfectia

when it fires up, how long does it run?...how does it die (slowly or suddenly), what does the tachometer do as it dies... dances around or or just a smooth loss of power

prop
Prop and the Blackhole Midget

Thanks for the replies. The tank had been off the car and had very little left in it. I have put two gallons of fresh.

I will take the rocker cover off tomorrow and chech the valves and then I will do a comp test
Tony Brough

I was thinking that if it has fuel, and has spark, fires but refuses to run it could be either sticking valve or a stuck ring so that there was low compression. But having said that, unless it was on more than one cylinder that probably wouldn't stop it from running - in a fashion.

I know you say that you have made no mechanical changes during storage, but are you absolutely sure you have the plug leads on correctly for the right firing order?
Guy W

Just checked and the compression readings are
1 - 170 psi
2 - 170 psi
3 - 170 psi
4 - 165 psi
I think tis is quite good for the original engine at about 85k.

Not 100% sure how to check if a valve is sticking so help here would be appreciated.

I am going to double check everything starting with static timing, electricery remove the fuel line from the pump and check its clear in case I am not getting enough fuel

Cheers

Tony
Tony Brough

I think a sticking valve or ring problem would tend to only affect the cylinder in question and the engine would run but badly, with a regular misfire, probably.
Your problem must be something that affects all the cylinders at once, such as poor fuel delivery or a distributor problem.
If you haven't fiddled with the mechanical side of things since it last ran, it sounds to me like a deterioration/blockage problem in the fuel or possibly a "tired" ignition component (condenser!!?)that is only working intermittently. Make sure the point faces are clean too and the screws in the distibutor are tight and the earth wire is secure.
JB Anderson

Hiya,

Assume the car is cranking at it's normal speed?


Whip off the air cleaners and try a whiff of easy start down each carb. If it fires up on that you know the ignition is ok and it's a fuel prolem.


Are the plugs getting wet with fuel?

Many times I've got a car laid up after some time to start by tipping a little bit of fuel down each plug hole, sort of crude "direct injection".



If not try a tow, they'll often fire up in a few yards when yr not asking the battery to crank it and start it!



Good luck.


Regards Steve
SR Smith 1

Compression is pretty reasonable, confirms that the valves aren't sticking and the rings are good. I think those figures at around 170psi are pretty good for a standard engine.

Did you check the firing order? An engine will run, after a fashion, with 2 wires swapped over, but will quickly die. (sorry, I only mean stop running, not terminal!)
Guy W

Daft question, have you checked the dash pot oil levels?
Pete Ottewell

Thanks for all the replies.

It is definitely electricery related.

Fuel is fresh and flowing filtered to the carbs.
The air filters are off
Dash pots are topped up
Checked the firing order
I checked the static timing and that had not moved.
So I then tried to see if I had a spark from the coil to the block and it now appears I don't ...
I've got the battery on charge.
I will work through by Les Bengtson article to see if I can figure it out.

If I can't then I will be calling out for more help.

Regards

Tony
Tony Brough

If its been parked I'd check out the points - they corrode - clean and check gap.

R.
richard boobier

Hold up charlie brown...

It may well be electric, but that dosnt mean its an adjustment that came undone by just setting for 18 months

Id look at a more basic cause like bad grounds, and loose wires...sitting thur 2 winters it could well be a rusty bullet due to condensation

Try this test,
Run a jumper wire from the pos battry post to pos. Side of the coil, and try starting the car...

Prop
Prop and the Blackhole Midget

I thought it was always the condenser....
David Smith

I got her started tonight. It was an iffy connection inside the dissy.

Thanks again for all the ideas, now I can crack on getting the tick over and mixture sorted.

Cheers

Tony
Tony Brough

Tony,
thanks for reporting back, not everybody does

I think Richard was nearest, as you got to check the points you see the poor connection

don't forget to clean your air filters and perhaps an oil and filter change in a couple of months
Nigel Atkins

I think this is quite close too, not that it matters!

"Make sure the point faces are clean too and the screws in the distibutor are tight and the earth wire is secure."
JB Anderson

sorry JB I forgot your earlier post - what's that Richard up to trying to steal your lead :)
Nigel Atkins

NAH... All the credit goes to me... I called It !!! And nope im not sharing...it was all me....hahahaha




#### Id look at a more basic cause like bad grounds, and loose wires ####

Just kidding...about taking all the credit

Prop...."vanity is my favorite sin"
Prop and the Blackhole Midget

This thread was discussed between 27/04/2013 and 30/04/2013

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