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MG MGA - Help! Ignition troubles. AGAIN!

The 5-speed transmission installation is complete and I am looking forward to the test drive.

My car was running perfectly before the installation began. However, I am unable to get the engine to start now. In fact, I do not hear any evidence of firing. I was very very careful taking out and putting back the engine. Nothing was bumped or damaged in any way!

The attached photo shows the ignition wires in the proper firing order. The only time I touched the wires was to remove the spark plugs in order to rotate the crankshaft to test the motion of the new, 5-speed transmission. Even then I did not remove the wires from the distributor.

Steps I've taken:
- checked that the engine is grounded
- checked the inside the distributor
- checked the cylinders for getting gas
- checked other firing order combinations

Any and all advice is appreciated! I am out of ideas...







gerard hutchinson

Reconnected all earth leads/wires/connections?

Starter motor connected?

And having the engine the right way up usually helps. :)


Nigel Atkins

LOL!

Yes, the engine ground wire is connected in the same way before the engine was removed. How can I know the ground is proper?
gerard hutchinson

Is the rotor in place, and the carbon brush?
Bolney Coupe

Gerard,
It does sound like a "no-spark" problem.
Have you checked these things :-

If you lay a spark plug connected to its lead, on the engine and try the starter, do you get a spark?

If not,

Are you getting 12v at the coil with the ignition switched on?

Is there a gap in the points? (they may have closed up) You can manually quickly close the points and you should hear the coil trigger when you let the points open.

Condenser failed?

Has the carbon contact fallen out of the top of the distributor cap? (I have had that happen)

Points wires been disturbed or trapped so that the wires are shorted out. Check the insulating washers etc on the points.

Barney will have a more logical method of checking the ignition on his website.

Let us know how you get on.

Cheers
Colyn
Colyn Firth

The thing that strikes me immediately from the photograph is the position of the vacuum advance unit, which should be pointing straight up, near as dam it, not towards the front of the engine as you have it. Check you haven't put the distributor in 180 out. Also the current position of the distributer will make it hard to run the vacuum advance pipe to the rear carb. Could be the clue to the problem.
Best regards
Alan
AR Terry

An engine only needs fuel and spark to run
Basics first
Have you got fuel
Have you got spark
William Revit

Colyn, I have upgrade my distributor to electronic and no longer have points. I will remove a spark plug and check for spark!

AR Terry, My car was starting and running regularly with the distributor in that position. I have adjusted it in the past and the position in the picture provided the smoothest idle and reliable starting. Why would that change?
gerard hutchinson

William, I am getting fuel in each cylinder but i am not sure about spark. I will use Colyn's test idea this evening.

Also, How can I check the "grounding" of the engine? The ground cable is attached but how would I know the connection is working?
gerard hutchinson

As the starter motor is spinning I would think your ground is fine.

Steve
Steve Gyles

Gerard,
you could check the earth lead by using a continuity or other test on a multimeter but I don't trust modern cheap digital meters (very hit & miss as I found yet again only this week end). I'd get a good thick jump lead (that's in good condition) and carefully route it from the battery earth post clamp to somewhere near or on the earth point you want to test to bridge it, providing a second path for that lead. The thick lead directly from battery clamp to body, gearbox, engine or other suitable location should give a strong earth connection and path.

If doing this improves matters then that ground lead or connections are poor.
Nigel Atkins

I would try and go thro this a bit slower,

On the question of earth (ground) as Steve has said, if the starter motor is spinning, then that should be fine. That is easy enough to ascertain.
If its not spinning, then it is likely to be the earth, the battery connection, or the connections in between. That again should be straight forward.

Assuming it is spinning, do as Colyn suggests to see if you have a spark (be extremely careful as it is a very high voltage, so never touch). If there is no spark, then the problem is in the ignition circuit somewhere. Report back here and I am sure you will get more guidance. But if there is a spark that is not always conclusive as the voltage may not be high enough (I have that T Shirt!).
If you do have a spark, regardless of my T Shirt, I would check the fuel side. But I think you have checked the fuel is coming through ok already

Good luck, let us know

Graham V

I doubt if this entry won’t help!

In the mid 70s I visited an MGA ‘expert’ and he had an engine on the floor that had come from a car that wouldn’t run. He was turning the engine from the pulley and couldn’t work out what was wrong. I was standing back and quietly pointed out that the back of the engine wasn’t turning. Engine don’t run well with broken crankshafts.

There is no risk of libelling the expert now as he is dead but it was a very young Simon Robinson who was just starting his business in his uncle’s old barn on the Blubberhouse moors in Yorkshire. For those who don’t know shortly afterwards Simon moved his business to Darlington and a few years later sold the spares side it and that was the start of Moss in the UK. He continued dealing and restoring. As years went by I believe he got a bad reputation due to the distraction of his excessive interest in horse racing. Died a few years ago as notified through the MGCC Safety Fast.

Paul
Paul Dean

I would check you have spark from the high tension lead coming off the coil (pull the end out of the distributor cap and hold close to engine block) if you have spark, then check the same with a plug lead. Report back if you are not sure of what the results tell you.
Mike
Mike Ellsmore

New problem:
my car will idle but revving the engine makes it cut out...like its being turned off. what could cause this?
gerard hutchinson

Decomposed rubber grommets on the banjo bolt at junction of float chambers to throttle bodies. Can allow enough fuel flow to idle, but not enough fuel flow to run at higher speeds.

Could otherwise be crud in the drill hole at bottom of float chamber for the same result.
barneymg

Could also be electrical
Something like a broken wire in the dizzy being moved when the vac advance pulls on
Try it with the vac hose off and see if it still cuts out, also,While it's idling have a little push/pull on the wiring going into the distributor
Some of them electronic conversions have very tiny fragile wiring
William Revit

Instead of revving you could try pulling the choke/fast-idle cable to see what difference this makes, lock it off where it stalls and have a look at the carbs and linkages.

I'd also think of delicate ignition wires trapped and/or rubbing.

Also of course checking the oft forgotten 'bleeding obvious' of things like oil in the pots, cables linkages free, all leads, earths, petrol getting through as Barney's put.
Nigel Atkins

Gerrard,
you didn't tell us how you got the engine to start again, after it not responding at all to begin with.

Colyn
Colyn Firth

A big frustration on this site is when someone asks for help and a lot of people chip in with their ideas and suggestions and the asker goes quiet!
Mike
Mike Ellsmore

You're not wrong Mike--It's a real p**soff at times
William Revit

Be fair, it's only been 3 days and there's a lot going on in the world, and if you live in America you are ruled by Donald J. - if ever there was a time for friendly-fire.
Nigel Atkins

It has now been a couple of weeks since we last heard from Gerard on the issues he is having with his A and the queries raised. It might be worth any of his friends on this forum or living in his area checking that he is okay.
Mike
Mike Ellsmore

This thread was discussed between 15/03/2020 and 11/04/2020

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