MGB GT electronic ignition conversion - car won't start
Discussion
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.
Thanks in advance to anyone who can help.
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.
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.
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.
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.
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!
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 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 said:
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 laterperhaps 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
Edited by N5 NRO on Sunday 8th June 09:32
jagracer said:
I'm pretty sure you shouldn't have a ballast resistor on an electronic system. The ballast resistor is there to stop the points burning out but I would think you have a 12V coil, the ballast resistor will cut the voltage to around 8V except when you start it which probably why it'll run for a few seconds.
I've run a luminition system and while they do the job they are only as good at the distributor, with the 123 you get a brands new dizzy.
The instructions for the kit I used include bypassing the ballast resistor by wiring directly to a switched live on the fuse box, so I wouldn't have thought it was that. I assume with the car dying so quickly it might be difficult to test if the voltage is dropping?I've run a luminition system and while they do the job they are only as good at the distributor, with the 123 you get a brands new dizzy.
nta16 said:
oh it was serious but I'll continue to help with the car advice if I can (better to sell a car that's running than one that's not)
In that case I'll point out that the car isn't being sold - its worth more to us than anyone else and we have no need to sell it. It was taken off the road last year due to underbody rust and I'm enrolling on a welding course starting in September to take care of that in winter. I decided summer was a good time to get the mechanicals sorted first.As for the comments about having my cake and eating it and expecting other people to pay for my stuff, I'm not sure where that impression came from - I've not been out of full-time education or employment for 21 years and everything I have I paid for. All my cars, insurance and driving lessons were paid for by me and my house was bought without any financial support from relatives, on top of which neither my girlfriend nor I have any debt aside from a mortgage.
nta16 said:
there's a Midget owner with a similar problem with an Accuspark and IIRC another B owner so if/when they resolve their problems we'll see if the solution is applicable in your case
I'd be interested to hear what the issues turn out to be, although I am most likely to go with a kit from a more reputable company.nta16 said:
Midget owner thinks the problems was/were - poor fit of spade connectors, possibly turning the dissy too far and low battery charge - possibly a combination of all three, car is yet to be road tested
a battery in good condition and fully charge with the clamps, main leads and earths all clean, secure and protected will help with finding starting and electrical problem but a battery that got low in charge can hinder and even hide when you've resolved the problem
as you're absorbed with the problem it's hard to notice the point at which the battery become discharged where it seems ok but is actually below what is needed to get the car running
always fully charge the battery after lots of unsuccessfully attempts to start the car
Thanks for the update - will get the battery plugged in this evening and make sure it's fully charged for my next attempt. If that still doesn't work I'll be reverting to points and condenser for the time being until I have a better electronic kit. Thanks again for all your help - will keep this thread updated if I manage to make any progress.a battery in good condition and fully charge with the clamps, main leads and earths all clean, secure and protected will help with finding starting and electrical problem but a battery that got low in charge can hinder and even hide when you've resolved the problem
as you're absorbed with the problem it's hard to notice the point at which the battery become discharged where it seems ok but is actually below what is needed to get the car running
always fully charge the battery after lots of unsuccessfully attempts to start the car
LordBretSinclair said:
Thanks again for all the advice and suggestions - I will definitely keep this thread updated with any progress I manage to make.
I know that my HT leads are (or at least were very recently) working, however they are a few years old and weren't the highest quality, so were due to be replaced anyway - I'll get this done sooner rather than later.
As for the shim/washer removal - I'll have a look into it, however as I've tested for a spark at the plugs and something's definitely getting through (even though it may not be enough to maintain the engine), I'm assuming that may not be the problem with my car?
The car's now plugged in and I'm hoping to get a couple of hours in the garage at the weekend to see if I can get any further.
I know that my HT leads are (or at least were very recently) working, however they are a few years old and weren't the highest quality, so were due to be replaced anyway - I'll get this done sooner rather than later.
As for the shim/washer removal - I'll have a look into it, however as I've tested for a spark at the plugs and something's definitely getting through (even though it may not be enough to maintain the engine), I'm assuming that may not be the problem with my car?
The car's now plugged in and I'm hoping to get a couple of hours in the garage at the weekend to see if I can get any further.
nta16 said:
pain though it is it might be an idea to get the batteries out of the car to charge slow them and that way you can check the post clamps are all clean and secure and the major leads and earths are in good condition particularly the long live lead
one chap found that although his leads looked OK he found under the plastic insulation the wire had crud
with the batteries out it also means you can check the condition of them better, clean post and tops of batteries, check electrode levels and top up if required
it also means if you have a slow drain on the batteries from something on the car the battery charger isn't fighting against it
it always pays to have batteries well charged and in good condition and connectors clean, secure and protected
a John Twist older vid on batteries - http://www.youtube.com/watch?v=UnbQ2G5K2zI
Thanks for those suggestions - will try to get the battery out one evening this week. I've just replaced a rather perished earth lead, so at least I know that's in good condition. I'm planning to work my way through all of the mechanical bits on the car this summer and replace anything that might need it in the future, so will definitely check everything over when I next get a bit of time in the garage.one chap found that although his leads looked OK he found under the plastic insulation the wire had crud
with the batteries out it also means you can check the condition of them better, clean post and tops of batteries, check electrode levels and top up if required
it also means if you have a slow drain on the batteries from something on the car the battery charger isn't fighting against it
it always pays to have batteries well charged and in good condition and connectors clean, secure and protected
a John Twist older vid on batteries - http://www.youtube.com/watch?v=UnbQ2G5K2zI
Finally got a few minutes in the garage today. House stuff has been keeping me busy recently, as well as having my Ford fail its MOT and need replacing unexpectedly.
Only a small update, but it lives! With the Accuspark kit fitted I managed to get the engine running. With a fully charged battery it started (just) and was then running very poorly, I know most of that is probably timing related, although I think the fuel level is perhaps too low (there was some in the filter, but not as much as usual). I'll get some more fuel in as soon as I get the chance and will then sort out my timing light to try to get things going properly.
Hopefully I'll have a better update soon, will post here whenever I manage to make some progress.
Only a small update, but it lives! With the Accuspark kit fitted I managed to get the engine running. With a fully charged battery it started (just) and was then running very poorly, I know most of that is probably timing related, although I think the fuel level is perhaps too low (there was some in the filter, but not as much as usual). I'll get some more fuel in as soon as I get the chance and will then sort out my timing light to try to get things going properly.
Hopefully I'll have a better update soon, will post here whenever I manage to make some progress.
Thanks for the advice - will definitely be keeping the car plugged in until it's back on the road.
The plugs are relatively new (well, low mileage anyway), but one appears to have a slight crack in it, so I'll replace them along with the leads. I've never adjusted tappets before, but it doesn't seem too difficult from what I can see online so I'll give that a go once I have the new leads and plugs in. The carbs definitely need some tweaking - I had a garage "sort" the timing and carbs just before taking the car off the road, but they did an awful job of it. The rotor arm is one of the red ones, so should be ok and I have a spare dissy cap ready to fit.
Hopefully it'll be running right soon!
The plugs are relatively new (well, low mileage anyway), but one appears to have a slight crack in it, so I'll replace them along with the leads. I've never adjusted tappets before, but it doesn't seem too difficult from what I can see online so I'll give that a go once I have the new leads and plugs in. The carbs definitely need some tweaking - I had a garage "sort" the timing and carbs just before taking the car off the road, but they did an awful job of it. The rotor arm is one of the red ones, so should be ok and I have a spare dissy cap ready to fit.
Hopefully it'll be running right soon!
nta16 said:
as PH appears to be playing up today and I've just lost my post have the raw info -
this web site is full of info, Paul Hunt's mgb-stuff - http://www.mgb-stuff.org.uk/hammertext.htm
among John Twists 200+ video, many on or relating to Bs, are these on carbs
35 Tuning HIF Carburetters - http://www.youtube.com/watch?v=ASeMfXfjNpw&fea...
147 MG Carburetter Tuning - http://www.youtube.com/watch?v=4nvGLgO6pj0&fea...
44 Secrets of the SU Carburettor Part 1 of 2 - http://www.youtube.com/watch?v=7GRAcqDySog&fea...
43 Secrets of the SU Part 2 of 2 - http://www.youtube.com/watch?v=60Bj_2cZQnc&fea...
41 Matching SU Air Pistons - http://www.youtube.com/watch?v=IfU47Oqq9wA
123 MG Carburetors & Doors (first part needles and seats, springs and carb oil) –
http://www.youtube.com/watch?v=v9QI3NlvwiY&fea...
222 MG SU Carburetters: Setting the Float Height - http://www.youtube.com/watch?v=82YNx-RkGNI&lis...
232 MG Carburetter Needles and Seats (Needle and seat) - http://www.youtube.com/watch?v=pVX_JClyeDQ&lis...
HS Carburetor Jet Repair - http://www.youtube.com/watch?v=Elgfc1xZkt8&fea...
Woah - thanks for digging all those out! this web site is full of info, Paul Hunt's mgb-stuff - http://www.mgb-stuff.org.uk/hammertext.htm
among John Twists 200+ video, many on or relating to Bs, are these on carbs
35 Tuning HIF Carburetters - http://www.youtube.com/watch?v=ASeMfXfjNpw&fea...
147 MG Carburetter Tuning - http://www.youtube.com/watch?v=4nvGLgO6pj0&fea...
44 Secrets of the SU Carburettor Part 1 of 2 - http://www.youtube.com/watch?v=7GRAcqDySog&fea...
43 Secrets of the SU Part 2 of 2 - http://www.youtube.com/watch?v=60Bj_2cZQnc&fea...
41 Matching SU Air Pistons - http://www.youtube.com/watch?v=IfU47Oqq9wA
123 MG Carburetors & Doors (first part needles and seats, springs and carb oil) –
http://www.youtube.com/watch?v=v9QI3NlvwiY&fea...
222 MG SU Carburetters: Setting the Float Height - http://www.youtube.com/watch?v=82YNx-RkGNI&lis...
232 MG Carburetter Needles and Seats (Needle and seat) - http://www.youtube.com/watch?v=pVX_JClyeDQ&lis...
HS Carburetor Jet Repair - http://www.youtube.com/watch?v=Elgfc1xZkt8&fea...
Edited by nta16 on Friday 18th July 11:34
Will start making my way through them this week, hoping to get the new parts I need next month and then I should have everything running properly not long after. I think the carbs need a rebuild and a few bits replacing, so those videos will be particularly helpful.
Didn't realise it had been so long since I updated this!
I eventually got the car started using the AccuSpark kit (fully charged battery and lots of fiddling), however it was running VERY poorly. When I connected the spark plug testers I could see that there was a strong spark on cylinder 1, but next to nothing on the other three and nothing I did seemed to make any difference. I have since switched back to points and condenser and the engine is running much better than when I last drove it. I adjusted the tappets and found some of them had no clearance at all, so I think some valves weren't closing properly and what I had previously thought was a misfire was just a lack of compression (and the garage I asked to sort the timing etc. out didn't bother to check it seems).
I'll still be converting to a 123 distributor later in the year, but I'm going to focus on getting the car back on the road first. The only things which really need doing are some welding (got a welder now and have been practising), some rust proofing and new coolant pipes. In the summer I will fit a stainless exhaust, new distributor and service the carbs.
Thanks again for all the help and advice last year - I really didn't want to be defeated, but I'm pretty sure the kit I had was faulty (or at least that's what I'll tell myself!).
I eventually got the car started using the AccuSpark kit (fully charged battery and lots of fiddling), however it was running VERY poorly. When I connected the spark plug testers I could see that there was a strong spark on cylinder 1, but next to nothing on the other three and nothing I did seemed to make any difference. I have since switched back to points and condenser and the engine is running much better than when I last drove it. I adjusted the tappets and found some of them had no clearance at all, so I think some valves weren't closing properly and what I had previously thought was a misfire was just a lack of compression (and the garage I asked to sort the timing etc. out didn't bother to check it seems).
I'll still be converting to a 123 distributor later in the year, but I'm going to focus on getting the car back on the road first. The only things which really need doing are some welding (got a welder now and have been practising), some rust proofing and new coolant pipes. In the summer I will fit a stainless exhaust, new distributor and service the carbs.
Thanks again for all the help and advice last year - I really didn't want to be defeated, but I'm pretty sure the kit I had was faulty (or at least that's what I'll tell myself!).
Once again I've left it for far too long since my last update - thanks for the replies back when I last posted in January.
My MG is now back on the road! It isn't running very well - initially I thought ignition and whilst I will be changing to a 123 distributor I can't justify the cost at the moment (over £650 to get the car back on the road, plus I'm getting married next year so I've been trying to work out what needs doing and what I want to do). As a temporary alternative to points and condenser I decided I had nothing to lose trying a new Accuspark kit - by buying a new one I knew I'd have a guarantee and warranty, so if it didn't work or if it breaks I'm covered. I tried fitting it on Wednesday evening and the car started first time, I adjusted the timing and it seems to be running far better than on the old setup. I fitted it the same as the old unit I had, so I'm assuming the other one was broken - there are a few definite changes in the design of the two. I'll still keep a set of points and condenser on board just in case though.
As for the still not running well - that appears to be carburetor-related. It was running particularly poorly yesterday on my way home from work so I pulled over to have a look and could see fuel pouring out of the overflow pipe on the back carburetor. A quick tap sorted it out, however pretty much as soon as I rejoined the main road it was flooding again and continued to get worse until I eventually got home. It runs fine from cold for about 15 minutes, but once it's up to temperature the problems start. I've ordered a carb. overhaul kit and a new pair of needle valves which I intend to sort over the weekend while re-watching some of the videos Nigel linked earlier in this thread.
After two years off the road I'm not too surprised there are a few issues, hopefully next week I'll have more reliable transport!
My MG is now back on the road! It isn't running very well - initially I thought ignition and whilst I will be changing to a 123 distributor I can't justify the cost at the moment (over £650 to get the car back on the road, plus I'm getting married next year so I've been trying to work out what needs doing and what I want to do). As a temporary alternative to points and condenser I decided I had nothing to lose trying a new Accuspark kit - by buying a new one I knew I'd have a guarantee and warranty, so if it didn't work or if it breaks I'm covered. I tried fitting it on Wednesday evening and the car started first time, I adjusted the timing and it seems to be running far better than on the old setup. I fitted it the same as the old unit I had, so I'm assuming the other one was broken - there are a few definite changes in the design of the two. I'll still keep a set of points and condenser on board just in case though.
As for the still not running well - that appears to be carburetor-related. It was running particularly poorly yesterday on my way home from work so I pulled over to have a look and could see fuel pouring out of the overflow pipe on the back carburetor. A quick tap sorted it out, however pretty much as soon as I rejoined the main road it was flooding again and continued to get worse until I eventually got home. It runs fine from cold for about 15 minutes, but once it's up to temperature the problems start. I've ordered a carb. overhaul kit and a new pair of needle valves which I intend to sort over the weekend while re-watching some of the videos Nigel linked earlier in this thread.
After two years off the road I'm not too surprised there are a few issues, hopefully next week I'll have more reliable transport!
Edited by N5 NRO on Friday 10th April 08:39
mgtony said:
Have you ordered new floats as well? Might be worth replacing them. Also how old is the fuel hose from the fuel filter to the carbs and the piece between the carbs? It could be perishing inside and sending crap into the carbs, only a few quid to replace and eliminates another possible cause. 
Haven't ordered new floats yet - I did consider it and will likely replace them in the near future though, or sooner if the new valves don't sort the flooding issue. Hadn't thought about the fuel pipe causing problems - it'll be about 3-4 years old and I've got some spare available so will replace that over the weekend too. Thanks for the advice Gassing Station | Classic Cars and Yesterday's Heroes | Top of Page | What's New | My Stuff