MGB GT electronic ignition conversion - car won't start

[N5 NRO]

I'm currently attempting to fit electronic ignition to my 1978 'B GT, however now it's all fitted I can't get the car to start. I've tested to ensure I'm getting a spark to all four cylinders and have made sure the leads are in the correct order. I'm certain it must be a timing issue as I know fuel is getting into the cylinders, however when I've tried adjusting the distributor I just can't get the damn thing to fire up. Is there anything I am doing wrong? (I'm positive there is, I just need someone to point it out for me!)

Thanks in advance to anyone who can help.

[Kinkell]

Distributor may be 180 degrees out. Or, try advancing distributor little by little if you think it's not far off ideal timing. My Escort won't even cough if timing is 5 degrees out.

[v8250]

OP, what type/manufacturer of electronic ignition and distributor are you using? Also, is your car a ballast or non-ballast MGB?

Chance are it's just a silly error upon install so should be able to rectify...

[Slidingpillar]

Kinkell said:

Distributor may be 180 degrees out. Or, try advancing distributor little by little if you think it's not far off ideal timing. My Escort won't even cough if timing is 5 degrees out.

It's very easy to mis-time a car 180 out. You need to be sure what the valves are doing to tell the difference between the two TDCs

[N5 NRO]

Thanks for your replies; to answer some questions:

The electronic ignition was a kit from Accuspark, fitted to a Lucas 45D4 distributor and an Intermotor sports coil and I'm pretty sure I have a ballast resistor. I've connected the negative wire on the new module to the old wire for the negative side of the coil (which was previously used by the condenser) and the positive to a switched live on the fuse box (not through a fuse, as instructed). I don't think I'm timing things 180 out as I've set the engine to TDC and checked that the rotor arm is pointing roughly towards the lead for cylinder 1.

Am I best off just adjusting the timing by small increments until the car starts? I'm a little worried about this being harmful, but if it's the best way forward I'll keep trying tomorrow. I optimistically bought a timing light today for when I can eventually get it running again.

Thanks again for all your help.

[Slidingpillar]

Take the rocker cover off so that you can see what the valves are doing and thus will be able to tell the difference between TDC at firing, and TDC at the start of the intake stroke.

Don't know about that engine, but some are surprisingly tolerant of incorrect timing at idle and just advancing or retarding by 5 degrees could get you into a mess with no idea where you are.

In other works, start from scratch. I bet you are timing on the wrong stroke. Plenty of us have done it, but won't admit it. (I have).

By the way, the distributor turns at half engine speed so 180 there is 360 on the crank. Four stroke cycle is 720 degrees on the crank long.

Edited by Slidingpillar on Sunday 25th May 22:53

[b2hbm]

Try setting the timing roughly using a simple bulb test, just as you would do for the conventional CB points set up. (a bulb between earth & the coil distributor terminal will do the job, it should light up when you've got a spark.

When I fitted a pertronix system (similar to yours for some reason I found the timing slightly adrift. I just put it down to the relative positions of the magnet on the distributor shaft & the trigger module on the baseplate being different to the old CB points. If you're getting a spark at the plugs, then it's got to be timing.

Edited by b2hbm on Monday 26th May 06:46

[nta16]

very doubtful as it usually runs even if the firing order is out but perhaps if you also have the timing out - so did you remember the firing order is anti-clockwise/counter clockwise/CCW as viewing the dissy cap from above when it's in the car

assuming you've fitted the right unit for your car, check for trapped or chaffed wires inside and outside the dissy cap (I know it's a different make on this vid but the principle remains) - (from 2:30) http://www.youtube.com/watch?v=dZFCRf_2c1E

I don't know if you have your dissy also has that very thin and delicate earth wire that has a cover that could hide a break inside

have you replaced anything else at the same time as you say it was a kit?

much as I loathe to say it how about fitting the points back in to see if the car starts and runs

the electronic igniters are usually good things to have fitted but they only deal with the top of the dissy the rest is still probably well worn, I've read they were out within two or three years of leaving the factory so imagine after decades, you might find you dance around with the timing light

finally, a daft one I know, you have checked petrol is getting through or that you've not run out

Edited by nta16 on Tuesday 27th May 15:21

[N5 NRO]

Thanks again for all the posts and help so far; it's much appreciated!

I've checked and made sure I'm not 180 degrees out and have continued fiddling with the timing. All of the connections look ok (although the wire which used to connect to the condenser is looking a little bit past its best, however it seemed fine when running the old set-up before I tried electronic). I've also tested for a spark at the plugs and it's firing on all of them, so I don't think any of the wiring is at fault.

I did manage to start the car yesterday, but only very briefly - it cut out again after just a second or two, and was very rough for that moment. I can't watch the YouTube video at the moment as I'm at work, but I'll have a look when I get home to see if it shows anything I've done differently.

If I can't get it running by the weekend I think I'll revert back to my points and condenser to try to get the timing right with them before swapping back to the new set up.

As for the petrol, there is definitely some getting into the engine - I can see it in the filter and the plugs are wet when I've checked. I know it's been in there for over a year though and is running low, so I'll be topping up a little soon, although I don't think it's the issue.

ETA: I've also checked and made sure I have the firing order correct.

[Faust66]

I had a similar problem when I tried to fit an Accuspark unit to my car... The first unit allowed my engine to run very badly for a few seconds and then it died - it sounded like it was only firing on 2 cylinders. The car then refused to start again, so my neighbour and I (hes an ex-mechanic) spent days trying to get the motor to run with no results. My symptoms were near a damn identical to yours OP. I eventually threw the towel in and got the module tested by an auto electrician... his opinion was "its st, send it back".

I contacted the ebay seller, who, to be fair, sent me a replacement out free of charge.

Once again, my engine ran for a few seconds and then died... I have to admit that there was fair bit of swearing at this point! So I refitted the original points & condenser and she fired straight up. I've fitted a couple of similar units (Aldon Ignitor) to other cars and never had a problem. I'm well aware of the dangers of fitting the module incorrectly - i.e. you'll burn it out, and I certainly didn't do this.

Since this week long debacle Ive stuck with the original points and condenser system and I've had no problems. I am toying with the idea of a 123 electronic ignition conversion, but I like to stick to the first law of running a classic car (if it aint broke, then dont fix it). I also quite like gapping points every so often as it's a strangely satisfying process IMO.

Maybe I was just unlucky and was sent 2 duff units, but I'd never go near this particular system again.

Edited by Faust66 on Tuesday 27th May 12:35

[Hooli]

I didn't think condensers were used in electronic systems? or does it vary by kit?

[nta16]

Faust66 said:

Since this week long debacle Ive stuck with the original points and condenser system and I've had no problems. I am toying with the idea of a 123 electronic ignition conversion, but I like to stick to the first law of running a classic car (if it aint broke, then dont fix it). I also quite like gapping points every so often as it's a strangely satisfying process IMO.

I too follow the idea of leaving things alone if they're working well but it's also great to get proper improvements and have things running at full potential performance

I'd strongly advise you to go with a 123 replacement, what you had before was built down to a price so failures must be expected

plus the 123 is a fully electronic dissy so replacing the bottom worn part of a dissy as well as the top with new and electronic, you don't need to buy the programable one unless you want to

with the 123 you'll find improvements throughout the rev range from idle onwards, you'll soon forget about farting about setting points as you'll be spending more time enjoying driving the car (a novel idea to some classic owners)

I went from a good Aldon igniter head to a 123 and found a very noticeable improvement

fully service your car, take the 123 over to Peter Burgess for him to fit it and set up the engine and carbs then you can enjoy driving the car and forget about fiddling with such things

http://www.peter-burgess.com/

[nta16]

Nick,
I didn't mention it before because usually it brings responses from those with Accuspark that their units work fine but think about what you get for the cost especially if you buy a kit, something has to give at those low prices

I know a MGB owner told me he bought the whole kit and found the HT lead set to be poor build quality at least

and I've also heard of Accuspark igniters failing well before they should, a well built electronic unit could last 20+ years

if you try to run a car on the very cheap then often what you get is a car that doesn't run anywhere near as good as it could or should

[jagracer]

I'm another one for the 123 Ignition system, I've had one fitted to my race car for a few years and can't fault it. My MGB has some fancy electronic set up that works OK but if ever it gives trouble I'll fit a 123.
OP if you have help then you could try slackening off the distributor and rotate it while someone sits in and sees if it'll start.
Also if you have a ballast resistor try bypassing it as you may have a 12V coil which is not getting enough power, also make sure your battery is fully charged and make sure the plugs aren't soaked in petrol.

[T0nup]

Acuspark. Cheep kak.

Also, if you read the instructions I think you will find it says the unit must not be used with high performance coils. Also, the system must be 12 volt, so no ballast resistor. Also, if you for any reason connected the unit to the coil with the wires switched and tried to start the engine... Toss the unit away, it's fked.

Much better to spend the extra for a Lumenition kit.

[N5 NRO]

Thanks to everyone who has posted since I was last on. I've tried starting with one hand cranking the engine and the other twisting the distributor and still only managed a couple of seconds of rough running before dying (as someone else said, it sounded like it was only running on two cylinders).

In light of that and the advice here I think I'll abandon my Accuspark kit and go for something a little better (I'll admit I was a little naive thinking something that cheap would work as well as the pricier stuff). With regards to the 123 systems people have recommended, would that be number 88 here: http://www.mgocspares.co.uk/acatalog/MGOC_SPARES_E...MGB__18.html ? If so it'll be a little out of my reach for a while yet, however would something from Lumenition work well instead? Such as number 77 here: http://www.mgocspares.co.uk/acatalog/MGOC_SPARES_E...18.html ?

Thanks again for everyone's help - it's reassuring to know it might not be me!

[nta16]

N5 NRO said:

With regards to the 123 systems people have recommended, would that be number 88 here:

if with vacuum advance then yes

N5 NRO said:

would something from Lumenition work well instead? Such as number 77

yes it would and for around the same price you could consider an Aldon unit (which I think are Petronix labelled up as Aldon) or get a Petronix from the expert the Distributor Doctor - http://www.distributordoctor.com/

of course fitting an igniter head still leaves the worn rest of the dissy, I was told that dissys we were out of tune within 2/3 years of leaving the factory so you can imagine they won't be better after decades of use, the 123 is electronic throughout, the bottom of your dissy can be rebuilt, that's what the Dissy Doc is all about but I don't know how long these rebuilt units last before mechanical wear starts again or the cost

don't get the extra power coil set up as you don't need it plus if you decide to go to a 123 later you don't need it

whatever you get be careful with the installation as regards those delicate wires, make sure they don't chaff inside the cap on the moving plate or outside the cap

if you need anything for your existing dissy like the earth strap then the Dissy Doc is were to go

Edited by nta16 on Saturday 7th June 12:50

[nta16]

just re-reading one of your posts - are you sure you've got the Intermotor sports coil suitable for ballast resistor ?

[N5 NRO]

nta16 said:

just re-reading one of your posts - are you sure you've got the Intermotor sports coil suitable for ballast resistor ?

I believe so, I had it fitted for two years before taking the car off the road - would it run if it was the wrong type?

Thanks for the link - I would definitely rather go down the route of a new 123 dissy, however I've just bought a house and apparently I need to "prioritise" and may have to keep the existing one for the time being. I definitely want the electronic ignition though, but may get a reconditioned dissy next summer instead.

[nta16]

N5 NRO said:

I believe so, I had it fitted for two years before taking the car off the road - would it run if it was the wrong type?

you'd have noticed before now

N5 NRO said:

... however I've just bought a house and apparently I need to "prioritise"

yes you do! unless you're of the generation and mind set that you can have your cake and eat it and possibly even get someone else to pay for it now or later

perhaps you should sell the MGB and cash in now for your priorities and buy again when you can better afford it

I bet you loved that bit of advice