I have replaced the following on my S130, new distributor & leads, new coil, new solenoid, new plugs. The Dellorto’s have been professionally rebuilt. The car has been off the road for approx. seven years. After a long time checking all connections on the wiring because it would not fire, I finally managed to get it to run. Now a week later it’s back to square one again, it will not fire!
My model is the one with two wires from the plus side of the coil, & has the anti-theft switch fitted, which works because it blows the air horn when you flick it with the ignition on. I have tried replacing both coil & solenoid with the old ones, but it makes no difference.
Has anybody any ideas? Thanks, John.
Hi John
I’ve had similar probs in the past with merely removing distributor and changing points,condenser nd then replacing distributor back in what I thought was EXACTLY the same place. Read lots of threads on here on esoteric aspects of timing curves, electronic ignition, micro adjustments to the carbs etc and it’s all good stuff ONCE you’ve got the engine running!
At this stage go back to basics. I’m assuing that engine is basically OK and carbs same after rebuild.
There are only three things you need to make any engine run- fuel. a spark and the valves to close and open- all at the right time. So first check spark (distributor) timing. Set static at 10-12 degrees btdc. Check your dellorto’s idol settings to two turns back from fully closed ( when closing just lightly turn them, dont screw them in hard). Start engine and it may run like a pig or it may run OK but it should run. If it doesn’t then remove plug leads and check for a spark at each lead end. Remove plugs immediately after trying to start and smell for petrol. If plugs sparking, and petrol present check your plug firing order. Only then try varying things. First try idle screws 1.5 turns out. If no go return them to two turns out. Then try varying static setting BUT it will only be slightly out from a starting position if set at 10 - 12 degrees initially. If no spark then we can fault trace for wiring via ignition circuit - switches, tacho and coil. If no smell of petrol then we can check feed or watered down fuel. Good luck
ps - Don’t forget to check that you have the coil connected the right way round to earth. Negative or positive as appropriate.
Despite your belief that it’s a good 'un I’d still suspect the anti-theft switch -they’re notorious for causing seemingly inexplicable ignition breakdowns.
Having suffered a baffling intermittent failure of sparks on my car over a long period, I asked a well-experienced Lotus man for ideas. ‘Has it still got the anti-theft switch on it?’ he asked. ‘Yes,’ says I. ‘Get rid of it,’ says he. However, not fancying all that fiddling about behind the dash to remove the wiring, I merely bridged the ignition contacts on the rear of the switch with solder and the ignition problems disappeared.
This fix also means that the horn-warning is still operative when the switch is on so that a thief could start the car but immediately the horn would start sounding and continue to do so as he was driving away. Possibly enough to deter the thief or perhaps to alert me or others to the theft.
Have you checked the voltage you are getting at the coil? Without a good strong supply you can still have a spark but not strong enough to ignite anything.
I had the same problem on my car. I only had 9.5V at the coil, initially I solved it with a ballast resistor but ultimately converted to electronic ignition - Ignitor.
Since then I have never had a problem with starting - regardless of voltage.
Try running a wire from the positive side of the solenoid down to the + side of the coil - This should give you a direct feed to the coil (ignition light should be on) - Then try starting the car.
Don’t leave it too long or you will burn out the coil. If it fire’s then you need to look at all of the connections as there is a poor one some where.
Good luck
Dave
I am still struggling to get the car started. I have pulled the dash forward to check all the contacts etc. and have also soldered up the terminals on the anti theft switch. One thing that puzzles me ---- the white & white/yellow wires on the back of the tacho all show current on the test meter when the ignition is off, but are all dead when the ignition is on. Should this be normal?
I would appreciate any help. thanks John
Hi John - With the ignition turned off check to see if you are getting a voltage at the + (white/yellow cable) at the coil and then turn the ignition on does it change?
Have you checked out all of your earth straps and earthing points? Do you have an earth strap that connects the engine to the chassis bridging the rubber engine mount?
Have you had the alternator checked out?
I will keep thinking and let you know if I come up with anything
Dave
John
Sounds like you need help, whereabouts are you?
John 
Dave, I am getting power at the yellow/white wire at the connection to the coil when the ignition is off, but guess what, nothing when the ignition is switched on (the red light is on when it should be). All the earthing points are connected correctly between engine, chassis & body, these all being cleaned with new bolts etc. when the chassis was changed.
Regarding the alternator, this appeared to be charging o.k. when I managed to get the car running a few weeks ago.
Thanks for your suggestions John.
Hi, John P. Clegg. I am just outside Bedford, not very near you! But thanks for the interest. John.
Hi John.
I can’t help with the wiring as I haven’t had my ignition switch off for a while but I guess you could check wiring via cicuit diags. Meanwhile a quick check would be to get a length of bell wire and run a lead direct from battery supply side (+ve on a -ve earth car) to the coil, bypassing the ig switch completely. This will show whether the ig switch/ tacho circuit has a break or miswire in it.
Hi John
I think you need to work through to eliminate the possible causes. Firstly disconnect the wires to the + side of the coil. Run a wire from the live side of the solenoid to the + side of the coil - This will ensure that you have a live feed. (you can do this from the large spade connector - be careful - it maybe worth disconnecting the battery for a minute)
Then try turning the engine over with the starter motor and see if she fires.
If she does then its go to be something to do with the ignition barrel.
The other issue is with a constant feed to the coil with the ignition off you are cooking the coil - Does it get hot with the ignition off?
Have a go and let me know what happens
Dave
Hi Dave, Here is the latest, following your advice.
Connected wire as you suggested from solenoid to + of coil, engine turned over but still not firing, but coil started to get hot.
With the ignition off the coil does not get even warm. I checked again & the yellow/white wire has still got power when the ignition is off, but still nothing when ignition is on.
Thanks very much for all suggestions John
P.S. Are you going to Stoneleigh?
John
You seem to have more than the usual challenges here. I would be inclined to break the problem down into manageble chunks.
A few questions to check basic assumptions
Were you the owner when the car last ran properly?
Do you have a spark at the plugs?
Do you have points or electronic ignition?
Are you getting fuel to the cylinders?
Is the coil ballasted?
Lets start with getting the motor to start by any means if neccessary and then move on to what may or may not be happening with the electrics.
Assuming you have conventional points. Suggest you disconnect the positive feed to the coil. Run a positve (assuming -ve earth) feed directly from the battery terminal. Remove spark plugs and check for spark. Make sure plugs are ok, not soaked with fuel etc.
If no spark replace points & condensor and repeat. Make sure that the coil connections are the correct side of the plastic insulator. If still no spark replace coil and repeat. If still no spark, connect 12v lamp to low side of the coil and ground on the engine block. Put car in top gear and push slowly forwards to rotate engine (plugs out will make it easier). As the points open the lamp will illuminate and extinguish as they close. Does this happen as described? If not points/condensor are defective or not wired correctly. Two other alternatives is the coil is open circuit or the points aren’t opening/closing (I assume the rotor is rotating and the distributor is not!).
If spark is ok, is the fuel getting through?
Refit plugs and spray instant start into the carbs as you turn the engine over does it fire?
If yes does it continue to run or expire as soon as the fumes are consumed? If it expires it could be lack of fuel through the carbs. Blocked fuel line, fuel pump or gummed up jets.
If it still doesn’t fire then a few alternatives. Ignition wires to the wrong plugs (We have all done it at some time) making timing 180 degrees out (looks fine on the lamp). Ignition timing set up statically on the wrong side of the distributor cam lobe (yes, some of us have done that too) so check the timing with a strobe to be sure. No compression (unlikely but worth a quick test). I assuming you haven’t messed with the valve timing.
Once you get the engine running I would only then start messing around with the behind dash wiring if it is still problematic.
Good Luck
Stuart
Hi John,
With the ignition off what voltage are you reading at the coil? You said that you have two wires to the ignition coil - have you been able to trace them back to there start point?
On my car I have two similar cables coming out of the same point in the harness - One connect to the coil and the other connect to the oil switch on the side of the block. Do you have these the correct way round?
Do you have 3 cables at this point in the loom?
Yes to Stoneleigh - Just need to find some money!!
Dave
Hi Dave, the two wires to the coil, the white/yellow goes into the harness & I am sure is the one to the tacho via the anti-theft switch. The blue/white one goes to the solenoid( same side as the battery feed.
I do not have a oil switch on the block, mine has a oil line direct to the gauge.
Thanks again for your help. John
Hi John,
I dug this out of the workshop manual, do you have the Ballast resistor fitted?
Dave
cold start.doc (548 KB)
The saga cotinues with my +2 not firing. A fellow Lotus owner with a Sprint (Identical engine to mine) very kindly brought me his distributor, leads and coil to swap over for mine. We set the timing up with his electrics, but still not a hint of firing. Connecting a wire direct from the live side of the solenoid to the coil still drew a blank, the coil did not even get warm.
What makes this even more frustrating is the fact that a few weeks ago, it did fire up, also the inconsistency of the problem e.g. when I ran a wire direct to my coil, it began to get warm.
Are there any electrical Lotus experts out there who could offer an explanation?
Thanks very much John.
John,
Are you getting any spark at the plugs what so ever?
After attempting to start the car have you checked the plugs for petrol fouling?
What spark plug gap do you have?
What is the condition of the rotor arm like?
Have you tried taking the plugs out and pouring a little petrol down each of the bores and then try starting her again?
If you have 12 volts to the coil (via what ever means), you have petrol to the carbs and engine, the timing is correct and the points gap is correct then it should start or at least fire.
Dave
Does anybody know the exact position of the ballast resistor in the wire between the coil & the tacho? I just wondered how much of the loom needs to be untaped to find it to bypass it. Hopefully this will be one step nearer to sorting the problem out.
Thanks again to Matt (Red +2) for his time & trouble this morning.
John.
John,
They can mount the ballast resistor almost anywhere, but on my car, the bolt that holds the coil to the inner wing (fender) also holds the ballast resistor. In other words, the ballast resistor is mounted right next to the coil. If yours is not, chances are the DPO removed it. They are available at any auto parts store. Just bring the coil in and ask what ballast resistor goes with it.
The factory ballast resistor on my Europa was mounted directly on the coil. It was a disk, about the size of an American quarter. One side of the disk was connected to the coil via the screw that held it on, and the other side was connected to the ignition wire via a screw that held the two together. What a piece of junk. I binned it and replaced it with a standard one designed to work with my Delco coil.
I caution you about one thing. If you have a coil that was designed to be used in conjunction with a ballast resistor however there is no ballast resistor in the car and your car will not start, adding a ballast resistor will not make the car come to life. It will only prolong the life of the coil and the points.
On the other hand, if you have a coil that was designed to be used without a ballast resistor and your car will not start, adding a ballast resistor will not help at all.
Hope this helps at all.