Sprint Won't Start

[xvivalve]

Do you have a supply to the distributor via the king lead?

You mean from the coil? Its brand new but I suppose nothing can be trusted to work well anymore.....

Yes, diagnosis from both ends helps locate the problem. If the coil supply is fine, then your problem is definitely in the distributor...

[MIG Wielder]

Back from the garage - no spark at the plugs, even after changing the leads

Thanks for your P.M.

O.K. the next thing I'd look for is with the engine turning over is the voltage at the coil negative going up and down between 0V and 12V ?

If its stuck at 12V is the connection into the Lumenition O.K. ?
If its stuck at 0V if you remove the negative lead to the coil do you get a spark at the main lead into the dizzy ?
Tony.

[Mahesh]

Just a quick note, the Lumenition Magnetronic units do not like being left with the ign on with no distributor spinning.

[ham204]

Back from the garage - no spark at the plugs, even after changing the leads

Thanks for your P.M.

O.K. the next thing I'd look for is with the engine turning over is the voltage at the coil negative going up and down between 0V and 12V ?

If its stuck at 12V is the connection into the Lumenition O.K. ?
If its stuck at 0V if you remove the negative lead to the coil do you get a spark at the main lead into the dizzy ?
Tony.

Thanks for this - the coil is 11.99 with the ignition on. Have to check with the engine turning

[ham204]

Just a quick note, the Lumenition Magnetronic units do not like being left with the ign on with no distributor spinning.

I always disconnect the battery so this can never happen - but good to know! Cheers

[ham204]

Ok problem found - the cam is spinning without turning the trigger!

I always thought the locking tabs to the cam were flimsy - they've given up the ghost and the car has not done more than a hundred miles.

[ham204]

Finally got the Sprint started and purring again - it was the module inside the distributor that was the culprit. I ended up removing all Lumenition stuff, including the coil, and went back to points. I'll probably fit a transistor electronic module later (which keeps the points) but for now I'm relieved the car is back on the road!

[trackerjack]

Years ago I was at a petrol station and the sprint would not start and it fooled several experienced mechanics who tried to help me and I ended up removing the distributer and spun it in my hand and got a shock! The rotor arm was earthing out through the spindle and a new rotor sorted it out. Sometimes its the little things that cause the most trouble.
Only last week I had my first NGK fail when my Special was suffering a slight misfire and I found that the ceramic centre of the plug had broken and when looked at seemed fine but turning the plug upside down the ceramic slid down and covered the spark I wish all faults were so cheap and easy to fix. I am still a fan of NGK and still only use them in preference to other brands.

[AlanH]

Mahesh had the same problem, I wonder if there is something about Sprints.

I have had one in my 1300 for years.

May be worth upgrading to Optronic.

[ham204]

I have electronic ignition in my Spitfire, Stag and a Series Land Rover and they never gave me any trouble at all.
My take on this episode is that the manufacturers do not specify that the modules are correct for a 44D4 so many, like me, went for the next best, ie the 45D4 which may not amount to the same. Apart from the Magnetronic, I had previously bought a Powerspark which absolutely refused to work from the minute I installed it in the Sprint. Having installed the points I immediately noticed that the engine sounds smoother, quieter and revs up better - but that could be my wishful thinking!

[Mahesh]

Weirdly I thought the same with the points being better than the magnetronic, but with the second magnetronic installed
I realised it was just me.

So far the 123 dizzy has proven to be the smoothest in all aspects, unfortunately cost is a major factor and I'm glad
I bought mine before the rest of the car used up all the money.

From what I've experienced (1975 to 1983) the optronic units are much more reliable, but still not exactly cheap, and
is the current build quality as of old ?

[Jod Clark]

I had a non-starter after a short lay up once; I had a fine spark at the plug and fuel delivery was fine. However, I was testing for a spark at the end of the lead; it took me quite a while to test the actual plugs as it seemed inconceivable that they'd all fail simultaneously...but they had! NOS Unipart plugs fresh out of the box had lasted less than a month!

What would cause all plugs to die simultaneously? Maybe a burst of energy from the coil?

It remains a mystery; I drove the car into the garage and a few weeks later it was dead. The plugs were part of a NOS lot I'd bought off ebay, I binned the other six on the assumption they were all equal!

Remember that Spitfire which did exactly the same thing when parked in your yard? Obviously Stourbridge is where parking slugs go to die.

The only brand of sparkling plug I've never had a problem with is Denso.

[Carledo]

I stopped buying Champion plugs 40 years ago, having bought a "workshop pack" of 50 N9Ys, 27 of which turned out to be duff!

I will continue to use NGKs, which I have NEVER had a single problem with in all the hundreds I have fitted over the years!

I was always a fan of the Lumenition Optronic system having my first in 1975 (my then place of work was an appointed Lumenition agent, I got a great deal!) but they were never cheap! I've never had so much faith in the cheaper Magnetronic and it seems my suspicions were well founded!

I use Accuspark ignition from Simon BBC on ebay for customer cars and haven't run into any major difficulties, but i've not yet fitted one to a Sprint's 44D4, I gather there are problems with rotor arm height that cause problems when using a kit designed for a 45D4, a problem that necessitates the use of an Austin Ambassador dizzy cap, rotor and leads. Sometime, I must give Simonbbc a ring and discuss the Sprint issue with him as I don't think he actually sells a unit for the 44D4, a dizzy which is unique to the Sprint AFAIK and therefore not a very big market place!

Steve

[ham204]

I use Accuspark ignition from Simon BBC on ebay for customer cars and haven't run into any major difficulties, but i've not yet fitted one to a Sprint's 44D4, I gather there are problems with rotor arm height that cause problems when using a kit designed for a 45D4, a problem that necessitates the use of an Austin Ambassador dizzy cap, rotor and leads. Sometime, I must give Simonbbc a ring and discuss the Sprint issue with him as I don't think he actually sells a unit for the 44D4, a dizzy which is unique to the Sprint AFAIK and therefore not a very big market place!

Steve

True - nobody sells anything for a 44D4, unless it's a full distributor. The problem with the height of the rotor is solved to some degree by sanding the rotor a couple of mm. Having said that, mine didn't work before and after sanding

[tony g]

I have electronic from bbc on my sprint with ambassador style cap and rotor. It works fine but the original one I bought never worked and they replaced it no problem after I went through some checks with him over the phone. I carry a built up spare dizzy with points just in case though.

Tony