52 replies to this topic

[nicomasala]

My god this thing is annoying,

New starter fitted, turns over nice and quick.

Still no spark, tried wiring direct and no joy.

I tried connecting multimeter to the distributor, and there is nothing whilst cranking or idle.

12v solid if I connect meter to positive of dizzy feed, and then a good earth. So I'm guessing that the module doesn't get an earth so doesn't function.

To check my wiring, coil has 12 to plus, and dizzy module to coil plus and minus, no other cables attached,

Please any other ideas before it goes back on ebay, I just can't see the wood for the trees right now

[Spider]

I tried connecting multimeter to the distributor, and there is nothing whilst cranking or idle.

 

Sorry, I can't recall if it's been suggested here, but it sounds to me like the Ignition Switch might be worn, taking power off the Ignition Circuit whilst cranking and intermittent at other times. It's a little common.
 

[gazza82]

Also do you know if the distributor was working? The electronics are sensitive and reversing the connections blows them easily.

[nicomasala]

Hi both, thanks for replying

Ignition switch is new, new distributor and coil fitted correctly wired.

See my problem

[nicomasala]

Hi all, hi just wanted to add my resolution in case anyone finds, I fitted points to the car and it fired straight away. No idea why the ellectronic if ignition didn't work

[Nial]

Good to hear you got it sorted.

 

Previously were you checking for a spark while spinning the engine on the starter or just statically? 

 

I think the electronic ignition needs to have the engine turning to detect whatever sensor is used and trigger a spark.

[sonscar]

Electronic ignition seems to have a mythical status.At its simplest it is a switch,on or off.A modern system with a wheel decoder will require the engine turning to synch and spark but a trigger type in the dissy just needs to pass the trigger.Steve..

[nicomasala]

Frustratingly, due to health etc, the car was put away for some time, I managed to get back to it recently, and itss till the same, starts and idles fine, but when revved, it's misfires and sounds rough. I've been over the whole ignition system again, all settings are as per.MG metro settings, dizzy is set correct at TDC, I just can't figure it, is it bad dizzy, no matter where the timing is set via dizzy rotation, I can set it up so it sounds nice, but the revs still stutter, timing light shows there is not a spark to detected when it misses

I'm so lost, it takes all the energy I have to get it out the garage, and its so sad to out it away not working , any help you can offered will be great fully received

[Lplus]

Where to start....

 

Has this occurred after any changes at all?

 

I note you use the phrase "it's still the same" so did it run fine before being put away or has this always been a problem with this transplant?

 

You imply it has an MG metro engine, so what did it have before and what age is the car as that may affect the type of wiring it has to the distributor.

 

Does it also have the MG metro 65D4 distributor?

 

You seem to have discovered the spark is failing at higher revs - either failing coil or the electronic unit could cause this but so might a low voltage as the revs rise.  That is something you could check if you have a voltmeter.

 

The correct timing for the MG metro with a 65D distributor is 10 degrees btdc at 1500 rpm, no vacuum advance.

[nicomasala]

Hi Lplus. 

 

when i picked this car up, the engine wasnt fitted, so i never heard it run before my ownership. 

 

"its still the same" is referring to my previous efforts to get it running, documented in this thread, It has always had this issue in my ownership 

 

1986 MG Metro Engine, in 1984 Mini Mayfair

 

It does not have the electronic ignition, it has a powerspark setup supplied as compatible with my setup, the original electronic ignition setup never sparked, so changed to points.

 

thanks

[Lplus]

Hi Lplus. 

 

when i picked this car up, the engine wasnt fitted, so i never heard it run before my ownership. 

 

"its still the same" is referring to my previous efforts to get it running, documented in this thread, It has always had this issue in my ownership 

 

1986 MG Metro Engine, in 1984 Mini Mayfair

 

It does not have the electronic ignition, it has a powerspark setup supplied as compatible with my setup, the original electronic ignition setup never sparked, so changed to points.

 

thanks

Well that serves me right for not noticing this was an old thread.

 

Back in post #35 you say it fired and ran on points.  You didn't mention any problem with misfiring at higher revs then.  Was it ok then?

[Ethel]

An '84 car is likely to have been fitted with ballasted ignition. Does it have a pink/white wire attached to the coil, or a wire going from the coil to the starter solenoid wire it connects to the aforementioned pink/white?

 

The significance is in which spec of coil you should be running, so let us know about any information printed on that as well.

 

You should always start your diagnosis with the ignition, but I'm getting a hunch this might be fuel related. Is there oil* in the carb dashpot & is the plunger screwed down properly? Checking is so quick & easy, it's worth it if only for elimination.

 

* You'll know if there's resistance when you remove the plunger and more so when you put it back in - it doesn't want filling to the brim!

[nicomasala]

Thanks for your replys

 

I got excited and answered that it started and ran, it will sit all day at idle no issue, but as soon as you rev, this misfires occur. 

 

The coil is wired direct to the fuse box, as it in a non ballast unit, the pink wire is there, but not used. 

 

Things currently swirling round my head, is the wire from the fuse box man enough?, and new set of plugs? 

[Lplus]

Thanks for your replys

 

I got excited and answered that it started and ran, it will sit all day at idle no issue, but as soon as you rev, this misfires occur. 

 

The coil is wired direct to the fuse box, as it in a non ballast unit, the pink wire is there, but not used. 

 

Things currently swirling round my head, is the wire from the fuse box man enough?, and new set of plugs? 

Ok so I'm assuming that this misfire at higher revs has been there since you fitted the points.

 

Is the misfire evident on all the plug leads or just some?

 

Related, is the misfire random or rhythmic?

 

If the wire from the fuse box is the same diameter as the white/pink wire it should be plenty large enough

 

Since the spark is going missing, I don't think it is a plug issue - or a fuel issue for that matter.

 

Were the points and condenser new?  is the coil a 3 ohm coil as for use with points and a 12 v feed?

 

as the vacuum advance operates with increased throttle the baseplate moves in the distributor - is anything touching and shorting out as the plate moves?

 

Is the condenser loose?

 

Are the points binding on the pivot and not able to follow the cam at higher speeds?

 

Just throwing out ideas here.

Edited by Lplus, 21 October 2024 - 12:44 PM.

[Ethel]

Try manually turning the rotor arm, it should move a bit & spring back under the centrifugal advance. You should also be able to generate just enough puff to blow into the vac advance pipe & see some movement. If you have a timing strobe it should also  show the effects of the advance systems if you rev the engine - with & without vac advance attached.

 

 

...I've seen fuelling cause faults that are a lot like ignition misfires - they are really: just with a different cause.

 

It's the reason you should always check out the ignition first. It can spark without fuel, but fuel can't burn without a spark. The confusion comes when both are borderline as fuel in the plug gap makes it easier to generate a spark.