Elan Sprint Starting Problem

[2cams70]

Aaah - time honoured test for spark but still effective! Pull a plug lead and crank whilst holding lead close to a metal part of the engine. Weak yellow spark = NG, Nice big blue spark = OK. Cautions! - don't run the lead open circuit particularly if you are running electronic ignition, don't do it near fuel of course and hold the lead with something non metallic so you don't get zapped.

[jgrover]

Hi,
I re-commissioned my 73 Elan (Dellortos) after a 10 year lay-up for my son's wedding in March. It all went well, but starting cold was a problem. As part of re-commissioning and since I have done the following:
New plugs, leads & caps
New fuel pump diaphragm
carbs cleaned, compressed air blown through, new o rings and accel diaphragms, accel squirts balanced, float height checked
Electronic "points" - (Accuspark) with dedicated feed wire
New fuel in new tank
New hose from pump to carbs
Timing is spot on
Carbs balanced with Gunson carb tune
Colourtunes (2) used to set idle mixture

AND IT STILL IS A PROBLEM COLD STARTING -- I have tried pumping, not pumping, choke full and half. Just before the battery dies it catches, then after 1 minute of running it is fine, re-starts first crank, it ticks over at 800 and once warmed up runs very well - it is just the cold start - 1 week and it is a problem.

Any ideas not already voiced?

Cheers

[mbell]

Have you tried jump starting it by hooking up between engine and battery connection on the solenoid?

I have similar issues with mine that I just put down to a weak battery. Jump starter connected closer to the engine and it starts fine. I think it might actually be there too much voltage drop when starting for my electronic ignition module to still work. So the jump start keeps the voltage high enough for it to work while starting.

[vxah]

" 1 week and it is a problem" has it been suggested that the carbs are dry due to evaporation and that mechanical fuel pump takes a long while to fill them? How about hooking up a cheap electric fuel pump in the boot to try? Just switch it on before trying to start and let it run a while.. Maybe the old pump is worn so that it's capacity is reduced causing delayed carb fill up?

[Mick6186]

My 1973 +2 with dellortos was very difficult starting from cold even with aldon ignitor, flamethrower coil and solid copper core plug leads. I fitted a facet fuel pump in line after the mechanical pump, operated from a discreet switch to fill the carbs then switched off. It was still difficult to start until I balanced the carbs with a 'synchroniser'. 6 pumps on the throttle, no choke and very slight throttle and it fires first time,
Mick

[2cams70]

If you have confirmed there is spark check that the accelerator pumps are squirting fuel into the carb throats when you pump the pedal. If there's raw fuel from the pumps squirting into the inlet tracts, you are cranking with the throttle butterflies open so enough air can enter and you have spark the engine should at the very least give an encouraging "kick" during cranking. It's the initial raw fuel from the accelerator pumps that gets things going. If there's no raw fuel being pumped work backward to determine the cause (faulty accelerator pumps, no fuel in float chamber, faulty fuel pump, etc.)

In Australia there's a raw fuel substitute product called "Start Ya Bastard" which can help a lot in such situations!

https://www.nulon.com.au/products/aeros ... ne-starter

If all that's in place and there's still no "kick" then the fuel may be old or it doesn't have enough "volatiles". A quick spray into the throats of "Start Ya Bastard" is a great help in those cases to get things going initially. It contains all that nasty volatile carcinogenic stuff such as xylene and toluene that they don't like to put a lot of in fuel these days. Don't sniff it!!

[jgrover]

Thanks for the suggestions - I was going to run a wire from the solenoid next (there is a terminal there) and then look in the plenum for fuel when pumped. Looks like we are all think same way.

Fuel is very fresh so don't think it is that and when I take fuel line off and crank, fuel instantly comes out of the hose so don't think it is a delivery problem. I did wonder about sticking float valves, so that is third on the list

Thanks everyone - I'll keep you posted if I find the cause

John G

[vxah]

Just be damn careful when messing about with petrol and sparks outside of the combustion chamber!
Asked a chap why his hands were all bandaged up a while ago. He said he was trying to start a Ford Corsair by tipping a little fuel down the carb, he retired to what seemed a safe distance while his mate cranked it over.. a spark from the starter solenoid on the inner wheel arch set his little pot of fuel on fire and he was holding it at the time... Spilling some of it with the shock of the ignition!

[69S4]

I have a similar problem with a number of my old motorcycles. Leave them a week and they won't start. The problem isn't old fuel - well not the fuel in the tank anyway, it's the more volatile parts of the fuel in the float chamber evaporating and leaving you with a low level of hard to atomise fuel. With the bikes it's a case of draining the float bowls and refilling. They then usually start straight away. With my Elan I put in an electric fuel pump (many years ago). Leave it for a week and you can hear the pump filling the float bowls and diluting out the heavy residual stuff. To do it with the std pump will need a fair bit of cranking before enough fresh fuel has come through.

[Craven]

Try two pumps then keep throttle wide open, foot off when fires!!

[2cams70]

Forgot to add another thing - check the static ignition timing too. If the timing is out a significant amount it can make cold starting difficult even with the primary components fuel, spark and air.

[jgrover]

OK, thanks for all the tips and now I think I have sorted it.

Fuel appeared to be getting into plenum when pedal pumped so I ran a wire from the solenoid to the coil as an auxiliary feed so that the coil gets max voltage possible during cranking, then this stops when engine fires and key released and "normal" feed takes over. This appears to work, 4 pumps, turn key, success!

BTW one problem with the Accuspark electronic trigger is that you can't static time the car using my usual method of putting a spare plug into #1 lead, turn engine to static timing mark then switch on ignition and turn distributor slowly from position of clearly retarded to more advanced then stop when the plug sparks. I spoke to Accuspark and they confirmed you just can't do this - the engine needs to be cranking at speed.

So solution as I say is to run a spare feed from solenoid output side to coil in addition to what is already there. This may also help if you have points, but a weak-ish battery.

Many thanks for all suggestions.

John G

[Craven]

John G
Seems you would do well to convert to a ballasted start system, 9 volt coil and ballast resistor but needs a new solenoid. Or is it already fitted to your car but not working correctly??