Lotus Elan and Lotus Elan Plus 2 Forums

i THINK YOU SHOULD CHECK THE FUEL PUMP WHEN THE MOTOR IS HOT - mechanical pump diaphragms will fail to make enough pressure when hot before they fail -- BE VERY CAREFUL NOT TO IGNITE THE CAR THOUGH -welcome to Lotus ownership -ED

ED

Can you please explain how I do that. I ask as I first thought to run her up then take off the carbs to check if the fuel pump is hot,but then I realised im not sure what im checking for,or if I need to remove the carbs to do it.Can you be a bit more specific,thanks

Greg,

The engine will idle at about 600 ish but on the whole it revs erraticaly and doesnt want to rev much higher than 3000. to be honest it came on very sudenly,which AB has pointed out. This leads me onto the ignition side of things. The point being that the same thing happend while driving back from Dorset to home a few years ago.After much asking and sugestions from the kind people on this site I changed the points,condensor and plugs.Leads were allready new and the PO had fitted a new Dizzy.As dirt in the fuel tank was sugested I purchased one from Andy Wiltshire,so that should cancel out that,but not dirt in the rest of the fuel system.Incedently the old tank is fine and clean.
Im leaning on the spark side of things first as it seems a good logical step to start with the simple things first,and I believe I have a coil that may do the trick.Im also thinking of an aldon ignitor 2,with a set of KVA 8.5mm leads which come with a new cap.This should all help and while fitting this lot,make up new electrical leads to replace the old ones.

I am also going to take the carbs of this weekend so I will look at taking the pump mesh out and giving it all a clean up,thanks for that tip

Paul

ok --extend the gas line away from the car over the fender with enough gas line on the out put side of the pump then pull the coil wire and turn the engine over ----you need about 2 to 4 psi to run a webber ----you also need a small pressure gauge with a 1/4 fitting to read the psi out put -be care full and remember there should be no spark around the gas and be in a well ventilated area --like out side -and keep a fire bottle close just in case = I hate working with fuel systems for the danger factor, please , remember safety above all else or just rebuild the pump any how as its most likely very old and then you know at least the pump will not let you down again your call -ed

ED,

I see,fairly simple i supose. Just to confirm,does that mean the thread going in too, and coming out off the fuel pump, is 1/4 inch?

Paul

well it may be I haven't measured mine lately ---check your diameter of out put fuel line --ed

The one thing not mentioned in the above lists that can cause these symptoms is a failing rotor arm in the distributor.

They can short-out at high voltage tracking your spark to the distributor spindle instead of the plugs. Such a fault is invisible even when you look very closely at the rotor arm.

Quickest diagnosis of this is simply to buy another one. They are only a few quid at Halfords.

Mine behaved very much like yours when the fuel pump failed, do you have the engine driven pump or an electric one.

The other thing I had years ago was a broken earth wire to the dstibutor base plate, took me ages to find it, as the ignition advanced at higher rpm it the connection broke down.

I would also double check the condensor or think about fitting one of the in distributor electonic units for around ?30, modern ignition components seem hopeless, I had 3 condensors in a year on my landrover.

Kevin

Right Guy's

Where do I start,Got to play with the elan today.I have taken off the webbers to strip them down and give them a good clean.

I have taken off the old coil ready to swap for a new shinny one.I have also taken off the dizzy cap to check the condition and it all looks OK

Greg, thanks for the tip about the mesh filter, As the Carbs are now out I took the glass bowl to cleen the filter, Inside the pump was more build up off crud than I have ever seen in my life. Large flakes and compacted dirt all over. Im surprised any fuel could get throught at all. So Im now in the process off giving it all a good service. Im hoping this will cure the fault.

Mike, I will get the dimensions of the inserts and post them tomorrow evening.

Thanks all,

Paul

Greg, My jack has dicided to go missing from my garage, I think its somthing to do with the rest of the stuff thats in there hidding it...!!!! So i wont be able to get measurements exactly,sorry. What I can tell you is that on the car the thicker spacer is very noticable and a mm or so thicker. I havent been able to get hold of Miles to find out the price or where he got them from. As soon as I can get the wheel off then ill let you know.

Paul

Hi all,
Just a message of thanks to all who have contributed to help me.and a bit of an update.I have cleaned out the carbs and the fuel pump as best as is possible to eliminate that side of the problem,and now I have ordered an Aldon Ignitor 2 and some leads so should be able to fit them soon.Kevin,I take your point,hence the dicission.I havent found an inline fuel filter with screw threads on to suit the pump yet,I want to fit one on the in and the out of the fuel pump.Greg,I spoke to Miles today,he doesnt suply them direct,but is getting in contact with the wheel suplier to see if they can be sold seperatly,ill let you know.
Once again,thanks for your help,Hopefully she will work for a bit longer when I have fitted the new ignition.Keep you all posted.

Paul,

I read what you put in Crusty's thread.

I had an Aldon igniter upset my tacho on an S4 so had it converted to voltage sensing rather than the current sensing. I could tell when I had the ignition sh*ts with the old one tacho set up. Lots of bounce.

Re: Aldon coil. A fair amount has been written on here in the past about coils with high Kv outputs. Just make sure that if you are running a 23D4 Dizzy that you don't use an Aldon Flamethrower or other high voltage coil. I think they are about 35 - 40Kv. A 23D4 cap will only take about 27Kv. I believe the SAE rating is less than 30K. I trashed about 3 Dizzy caps and a couple of rotor arms before I took it off. They are fine with more modern dizzies with better values of insulation.

Mine would be great for about 15 miles and then start to misfire like a pig. I would have to stop until it cooled or change the cap.

Just a thought!

Mike

Mike, Thanks for that,Im assured by the bloke at Aldon that the code 103TC on my dizzy is a 43d lucas built by Aldon themselfs.He didnt say anything about what you mention,suprise,or maybe its not a problem anymore.Is there much I can do about this?

Paul

Hi Paul,

Re Insulation. Yours is a later dizzy (I have one). They do, I belive, live up to higher coil voltages (if required). I talked to Aldon at the time and they knew about the old 23D4 caps (& arms) not being up to the higher output coils. It is only a problem if someone decides to fit a high output coil, like the Aldon Flamethrower, to a 23D4.

Re: Tacho. It is my experience that some current sensed ones are not upset by electronic ignition, but with the same type, on other cars, they have had to be converted to voltage sense (bounced like hell). I think there is lot posted on here about the type of tacho movements and problems. I suppose "suck it and see". My Plus two has a Luminition and it is stable with the old tacho. Not had long thou'.

Mike

Hi all,

Got back from work today,only to find the the postman had left me with a pressie.I now have a nice new set of 8mm NGK leads,a Flame Thrower coil and the Aldon Ignitor 2 unit.Small thing really.Its a bit dark outside so I think ill fit it in the morning and take her for a test drive.

I hope it works,Im still looking for a sutable inline fuel filter to screw into the pump outlet,if anyone has any ideas can you let me know

Thanks,

Paul

Hi every one,
just a quick question reference the rest of this thread,and a bit of an update.not long after putting the car back together I ended up with no spark at all,fault was traced to no power at the coil.strange, as there is still power at the solonoid.So I have decided to strip the engine loom back,and rebuild it to form a dedicated loom section for the ignition side.Its not such a hard job as most of it is in a bad state of repair and is almost falling off as it is.The question is purely one of advice really,while im there what else should I be looking at doing.what size of cable should i be using ect,and if anyone else has had to do this,what advicecan you give me?The main reason why im doing this instead of rewiring the complete car is I only want her running untill the winter then the EFI is getting fitted,so its a bit of a short term fix,however done properly.

Any advice?

Thanks,Paul.