Hot (not) starting

[collins_dan]

That is great to hear. I had a similar experience when I got rid of lumenition ignition, but my change was to pertronix. Can't for the life of me think of why your tach would over-read like that? Could it be voltage related?
Dan

[Steve G]

That is great to hear. I had a similar experience when I got rid of lumenition ignition, but my change was to pertronix.

That was going to be my direction but I thought I would try good old points and condenser first. I was told a lot of the issues are from the cheap Chinese 'Lucas' condensers packing up.

Can't for the life of me think of why your tach would over-read like that? Could it be voltage related?

I know, it's a bit of a head scratcher, it's all back to standard now and it was over reading before electronic rev limiter went in but that wouldn't affect it anyway. Seems to be exactly 150% too, so 4,000rpm on the digital timing light was 6,000rpm on the tach, 5K was 7.5K etc. I might hook it up to someone else's car before I pack it off to Speedy cables.

Edit: I've just read the Wiki article (the Wiki is up and running - when did that happen?): http://www.lotuselan.net/wiki/Bouncing_Tach and I think it holds the answer; "...and the second is wiring aftermarket electrical products (fuel pumps) to the coil circuit. "

I have an electric fuel pump. So Speedy Cables it is then!

[RogerFrench]

Steve, just a thought. Are you sure your digital light isn't set for a 6-cylinder engine? That would give the exact 50% difference.

Don't shoot me please, but I have seen this error before.

[Steve G]

Hi Roger, thanks for your suggestion. I hope not as that would mean I have set my rev limiter to 9,000rpm+ and I revved the engine to that around 10 times whilst setting it! It was bloody noisy doing it with my straight through exhaust and with it sitting in my open garage. It felt most inconsiderate and unneighbourly. I'm not sure my cast iron crank would have held up to those revs!

I am planning to check the ignition wiring to the Facet fuel pump, then reconnect to the ignition downstream from the tachometer if it isn't already.

If that doesn't work I am either going to send it off to Spida to get the current to voltage sensing conversion done or replace with a new Smiths classic electronic tach. I haven't decided yet.

Next job- work out how to fit a fuel sender to a foam filled tank and re plumb the extremely messy filter/pump/regulator arrangement and get rid of all the frightful 90's looking red anodised tat. Apparently oven cleaner on the filter will do the trick.

[theelanman]

Interesting read......as my car did this today......had to wait for about half an hour before it decided to start.......
Doh

[Steve G]

I went back to points ignition and problem solved. The lumenition module was getting hot and producing a weak spark.

[theelanman]

just thinking about 'heat soak'......
which part of the Luminition system is getting too hot?.......or in fact which bit at all.........
thanks
G

[Steve G]

just thinking about 'heat soak'......
which part of the Luminition system is getting too hot?.......or in fact which bit at all.........
thanks
G

I can't be 100% sure but it must have been the lumenition module. I moved it from its initial position of right in front of the intake trumpets (with one of the carb socks actually pressing against it) to right down in the nose where it could get some cold air through the grille and it seemed to help a bit but after an hour of driving on a summer's day it would still stall in traffic and then not restart. So I got some advice from a friend who works for CCK Historic and went back to points ignition, albeit with Swiftune points which are significantly better quality than standard and get used on all of their race cars. The car ran better and never had a problem starting again.

It could of course had been a faulty or worn out module (judging by the oxidisation of the aluminium it was at least five years old) but that wouldn't explain why it worked perfectly from cold and only started to produce a weak spark when the engine bay was hot.

Some people find the idea of running original points ignition completely abhorrent but personally I would rather have to gap the points once in a while than have to push the car to the verge and sit waiting for the engine to cool!

Good luck with diagnosing yours.

My best,

Steve

[davidc]

steve

do you have a link for the Swiftune points?

i used to use them on my mini but thought they only meddled with A series engines and not the twin cam?

i would certainly pay the extra for high quality given how much of a fiddle they are with carbs on to replace

David

[vxah]

Interesting read that, I had luminitoin on my +2 for thirty odd years with no problems! The module was mounted quite high on the o/s inner wing so I guess never got too hot although, it did get wet!

I have the same system on my Jensen Healey but with the module mounted on the bulkhead. Whenever I get stuck in traffic and the heat starts to build after 10 minutes or so, I know it will play up and then cut out! It usually begins with some misfiring and knocking from the engine and if I put the heater on full-hot I can delay the cut out for a bit! When I get out on the open road it is ok again or I have to sit and wait! I have long suspected the module as I have changed the trigger head etc to no avail.

I have changed the +2 now to Aldon amethyst mapable system with the intention of some improvements via a rolling road tune.
I consider modern good quality electronic upgrades to be superior to the old points systems as most distributors must be worn by now giving a bit spark scatter and, a better spark can be had with variable dwell?

[Steve G]

http://www.swiftune.com/Category/68/ignition.aspx

Red rotor arms and brown points.

[davidc]

Thanks