Lucas 23D Points Baseplate

[111Robin]

Unfortunately the headlights are electric. I've tested the plugged vacuum takeoff on the manifold and it's holding vacuum. I also blanked off the servo takeoff as I couldn't maintain vacuum on the servo with the handpump. I've just removed the Webers to replace the o rings as well. They were new during the rebuild so I doubt they were leaking but I'm leaving no stones unturned. The thackeray washers were correctly gapped as well so shouldn't be a vibration issue.

[SENC]

Not sure if there is an easy way to test, but Webers can also leak around the spindles and some say the leather seals that come in the kits are to blame. While the carbs are off, I think I'd use some compressed air to make sure all the circuits are open and free flowing and to look again at butterflies and how they're seating and opening and to look around at all the jets and valves and just make sure nothing obvious was left out upon rebuild. Sounds like your idle circuits must be functioning, so maybe mainly checking the main circuit and accel jets and balls/weights. If you do check all the bits, note sizes/markings and grab pictures along the way and post as many here work in their own webers and someone may notice something.

[mbell]

One thing to watch is if the tacho is working it not when it fails. If it seems to be about right then it's probably a fuel problem. If it's behaving strangely or drops to zero then it's probably an ignition issue.

[Sadbrewer]

I have no reason to doubt the distributor, aside from the electronic ignition. Timing is spot on and advance is per the book through the rev range. I have replaced the coil already as this was my initial suspicion. I did get the chance to pull the king lead after one breakdown and there was a spark. I have noticed the coil gets pretty hot to touch, not sure if it's excessive as I don't make a habit of feeling coils on my other cars. One thing I have to admit, when I made new HT leads initially I used copper wires, forgetting this was a no no with the EI. I have now made new leads with suppressed wire and caps, however perhaps the module has already been damaged as a result of using the copper leads. I'm kicking myself about this as it could be a reason, however it always starts and runs perfectly in the garage, up to normal temperature, never misses a beat. It's only once on the road with load on the engine it starts to act up. Perhaps a red herring but the one time it never broke down was a night run, headlamps on. I'm not sure if it was luck or if the draw o the alternator caused a reduction in the voltage going to the EI, perhaps the alternator output is too high. This is something I've yet to check.

In view of the coil getting so hot I would just swap it...another component to consider is the condensor, both can give intermittent faults but are cheap to replace.

[111Robin]

One thing to watch is if the tacho is working it not when it fails. If it seems to be about right then it's probably a fuel problem. If it's behaving strangely or drops to zero then it's probably an ignition issue.

The tacho is reading about 1000rpm below actual. I just put this down to it being incompatible with the electronic ignition.

[111Robin]

I have no reason to doubt the distributor, aside from the electronic ignition. Timing is spot on and advance is per the book through the rev range. I have replaced the coil already as this was my initial suspicion. I did get the chance to pull the king lead after one breakdown and there was a spark. I have noticed the coil gets pretty hot to touch, not sure if it's excessive as I don't make a habit of feeling coils on my other cars. One thing I have to admit, when I made new HT leads initially I used copper wires, forgetting this was a no no with the EI. I have now made new leads with suppressed wire and caps, however perhaps the module has already been damaged as a result of using the copper leads. I'm kicking myself about this as it could be a reason, however it always starts and runs perfectly in the garage, up to normal temperature, never misses a beat. It's only once on the road with load on the engine it starts to act up. Perhaps a red herring but the one time it never broke down was a night run, headlamps on. I'm not sure if it was luck or if the draw o the alternator caused a reduction in the voltage going to the EI, perhaps the alternator output is too high. This is something I've yet to check.

In view of the coil getting so hot I would just swap it...another component to consider is the condensor, both can give intermittent faults but are cheap to replace.

I haven't run it with points and condenser yet. The coil is new, it's getting hot with the electronic ignition. It is correct impedance, 3 ohms, no ballast resistor. I have heard of the coils frying due to insufficient dwell, not sure if that can apply to EI where the dwell period is fixed by the electronics. The way it runs in the garage wouldn't suggest the dwell was far off though so I don't know why the Coul is so hot. I'll see what it's like running on points.

[111Robin]

Not sure if there is an easy way to test, but Webers can also leak around the spindles and some say the leather seals that come in the kits are to blame. While the carbs are off, I think I'd use some compressed air to make sure all the circuits are open and free flowing and to look again at butterflies and how they're seating and opening and to look around at all the jets and valves and just make sure nothing obvious was left out upon rebuild. Sounds like your idle circuits must be functioning, so maybe mainly checking the main circuit and accel jets and balls/weights. If you do check all the bits, note sizes/markings and grab pictures along the way and post as many here work in their own webers and someone may notice something.

I have removed idle and main jets and blew through. The accelerator pumps are jetting out strong Jets when I open the throttle wide so look ok. Not sure about the butterflies, I can see them causing poor performance but not breaking down ?. When it happens I can dip the clutch and open the throttles fully and it picks up with the injected fuel, I can do this several times before it won't take any throttle and just dies. To me it looks like I'm emptying the float chambers but why would they be starved when the rest of the system looks to be supplying sufficient fuel ?. This would also tie in with it eventually restarting after quite a lot of cranking, filling the chambers. This was always my theory and why I fitted the nos pump but it made no difference. The chamber needle valves are new, all brass, and float heights are correct.

[mbell]

One thing to watch is if the tacho is working it not when it fails. If it seems to be about right then it's probably a fuel problem. If it's behaving strangely or drops to zero then it's probably an ignition issue.

The tacho is reading about 1000rpm below actual. I just put this down to it being incompatible with the electronic ignition.

I was referring to when the issue happens. If you can glance at the tacho it might give you clue on what the fault is.

[111Robin]

One thing to watch is if the tacho is working it not when it fails. If it seems to be about right then it's probably a fuel problem. If it's behaving strangely or drops to zero then it's probably an ignition issue.

The tacho is reading about 1000rpm below actual. I just put this down to it being incompatible with the electronic ignition.

I was referring to when the issue happens. If you can glance at the tacho it might give you clue on what the fault is.

Ah, sorry, I haven't really thought to look, too busy panicking trying to get the car to a safe location each time. I'm sure it'll happen again though and I'll try to remember to check the tacho.

[SENC]

What size needle valves do you have? Could they be too small to refill adequately.

What size fuel and air jets and what emulsion tubes? May as well rule out significant variances from standard being a problem.

You mention the accelerator pumps push a good flow when throttled - when idling they aren't dripping (even a little), are they?

Does the engine idle well/smoothly right after start-up, or does it take a bit to warm up and smooth out?

I'm asking these questions wondering if rather than being fuel starved you have the opposite problem... that the carbs are set too rich to achieve a smooth idle even when cool - but then once warm and with a load that over-rich condition becomes too much. Do you still have the cold start mechanism on the carbs and are they functional? Are they shutting all the way? Many have "hardwired" them closed to prevent then from vibrating open and providing additional fuel when not needed.

I should note, I'm no expert on these things - but have been learning my way around webers on my Seven so just sharing questions and problems I've worked through on getting that running well. I learned along the way I could fairly easily get it to idle smoothly but that didn't mean much when put under load. Several folks more experienced than me shared that these carbs won't idle smoothly when cold without some firm of enrichment - either cold start circuit or over-rich idle jets or idle jet screw too open.

The butterfly question was about confirming that they actually open fully - and also confirming that they are aligned with each other. One trick I learned to confirm they are aligned with each other is to put a flashlight in each intake/venturi (engine off) and pull the progression hole plugs. Then, looking down at the progression holes and manipulating the throttle by hand you can see whether the butterflies pass the holes at the same time.

[mbell]

I'm sure it'll happen again though and I'll try to remember to check the tacho.

Can also check the tacho when trying to restart after it has occurred. Will normally get some level of movement of the needle, which might not happen or be different to normal if ignition is working.

[Sadbrewer]

I have no reason to doubt the distributor, aside from the electronic ignition. Timing is spot on and advance is per the book through the rev range. I have replaced the coil already as this was my initial suspicion. I did get the chance to pull the king lead after one breakdown and there was a spark. I have noticed the coil gets pretty hot to touch, not sure if it's excessive as I don't make a habit of feeling coils on my other cars. One thing I have to admit, when I made new HT leads initially I used copper wires, forgetting this was a no no with the EI. I have now made new leads with suppressed wire and caps, however perhaps the module has already been damaged as a result of using the copper leads. I'm kicking myself about this as it could be a reason, however it always starts and runs perfectly in the garage, up to normal temperature, never misses a beat. It's only once on the road with load on the engine it starts to act up. Perhaps a red herring but the one time it never broke down was a night run, headlamps on. I'm not sure if it was luck or if the draw o the alternator caused a reduction in the voltage going to the EI, perhaps the alternator output is too high. This is something I've yet to check.

In view of the coil getting so hot I would just swap it...another component to consider is the condensor, both can give intermittent faults but are cheap to replace.

I haven't run it with points and condenser yet. The coil is new, it's getting hot with the electronic ignition. It is correct impedance, 3 ohms, no ballast resistor. I have heard of the coils frying due to insufficient dwell, not sure if that can apply to EI where the dwell period is fixed by the electronics. The way it runs in the garage wouldn't suggest the dwell was far off though so I don't know why the Coul is so hot. I'll see what it's like running on points.

Reading the thread Robin, I hope you don't mind me saying... I'm only trying to be helpful, but I think you are getting into a bit of a mess with a scattergun approach to various problems most of which probably don't exist.
I was born and brought up in the motor trade through until the 1980's...I admit I know nothing about electronic ignition, but Elans are simple pieces of kit...I wouldn't start pulling carbs or fuel pumps to pieces or thinking they may be to blame before absolutely eliminating the ignition side of things....I would return it back to original spec...as per the Lotus workshop manual with the old fashioned chalk marks and strobe light...if it's not, that you can always put the parts on E**y....first thing first though...consider what was the last modification you made before the problem started...the answer will most probably lie there.

[Andy8421]

I have replaced the coil already as this was my initial suspicion. I did get the chance to pull the king lead after one breakdown and there was a spark.

Robin, the trick with faults like this is to be systematic in tracking the problem down. Tough if the symptoms appear at difficult times, but probably worth having a few outings forcing the problem to occur on roads where you can stop easily and check what is going on.

FWIW, if you had a decent spark at the 'king lead' (I assume the lead from the coil to the distributor) when the fault appeared, then there is probably nothing wrong with the coil or the ignition module. Next step in the chain is to check the distributor cap and rotor arm. As suggested above carry a spare plug, and when the fault occurs, remove one of the plug leads from its plug and connect to the spare plug. Earth the thread of the plug against the engine and see if there is a spark when you turn the engine over. If you have a decent spark then the problem is likely fuel, if not then its the rotor arm or distributor cap - you could confirm this by checking you were still getting a decent spark at the 'king lead'.

I started playing with cars when I was in my early teens (60 now), and rotor arms and distributor caps never failed - I would only replace them if I trod on them. These days the damn things seem to fail much more frequently. Its a few years ago, but I went through 4 caps in the space of as many weeks - 'it was a bad batch, Sir'. They exhibited exactly the symptoms you describe. I only buy ignition components from DD now, and have always received very good service from him.

[111Robin]

I should add, I'm not new to working on cars of this era . My dad was a mechanic from the early 50s until he retired at 80 years old and I always worked with him as I grew up. I've owned classic cars for around forty years. I'm very well versed in diagnosing faults. I haven't just randomly started changing things. This car was a mess when I got it so I stripped everything from the engine so I could start from scratch and take it back to oem specification. The only aspect of this car I'm not familiar with is the Weber. Apart from an old BMW running twin Zeniths all of my cars have been exclusively SU carbureted. The ignition system is simple and I fitted nos Lucas cap and rotor arm as part of the rebuild, not to fix any issues. I also made a new set of HT leads as I always do when recommissioning a car I have no history of. On the fuel side I removed the tank so I could clean and paint it. I replaced the fuel line with the oem type. I replaced the fuel pump with a non oem type from Sue Miller (now replaced by a nos AC pump) I had the Webers fully rebuilt by an expert. This was all done to get everything back to scratch as it should be. I left the electronic ignition and coil as I saw no issues with them at that time and the previous owner had assured me that he had never broke down. So everything was back to oem apart from the ignition module. There is no fuel dripping from the venturis at idle. I have noted the jet sizes and these are correct for the Super SE specification of this engine. I haven't checked the size of the needle valves yet. I just haven't had the opportunity to perform the normal checks for fuel and ignition when it breaks down as the priority has always been to get it to a safe location, usually by churning it on the starter in first gear. I just wish it would fail in the garage but it never does. Let me see how it runs on points then I'll report back on my findings. All comments are much appreciated.
Thanks.

[JohnMorin]

What advance curve is it set to ?

It's this one.

Bits bought from Paul Matty many years ago fitted only recently and then as I said swapped out for an electronic distributor.

John