Electronic ignition

[PhilJane]

Hi,

My 1959 TR3A runs smoothly when thoroughly warmed through, although is always very slow to start requiring 2 or 3 fairly lengthy cranks of about 30 seconds each (with full choke) under most ambient conditions. Choke is still needed for about 5 minutes after start up. Appreciate it could be a fuel side problem here, but I wondered whether an electronic ignition system might help? I have been given a Newtronic ignition system (TT2970) still 'in the box' but am not sure of the polarity of the kit. Has anyone got advise either on the ignition system or the starting/cold running problems?

Thanks,Phil.

[Ashley James]

None at all! If the points etc are all correctly adjusted there will be no difference.

 

Sounds to me as though a tune up is needed. Very simple guidelines:

 

1. Set ignition timing

 

2. Take the lids off the float chambers and turn them upside down. With the float needles shutting of fuel supply a 7/16" drill shank should just fit under the forks.

 

3. Make sure floats don't have fuel in them.

 

4. With a digital vernier make sure that the main jets are between 35-38 thou below the jet bridge and while the dashpots are off, make sure the butterflies are evenly matched. I use a 0.00015 feeler with the tick over slowed right down. Make sure the grip is the same on both Carbs.

 

5. Re- fit dashpots a d fill tops with engine oil.

 

The car will now start and run perfectly. Guaranteed!

 

Ash

Edited December 30, 2010 by Ashley James

[jean]

Very correct, in fact electronic ignition has mainly advantages at high rpm. Its an electronic trigger against a mechanical trigger to control the charge and decharge of the coil. The electronic device is in so far faster, allowing the coil more time to charge and thus giving a better spark, at very low RPM it's less important.

Happy New Year

[John Bazzano]

Phil,

 

The symptoms you list are exactly what happens with my TR2 if I forget to manually pump up the carbs with

the fuel pump. Just keep working the lever until the "feel" changes. Normally for me, it will start right

up with very minimal cranking. Still will need the choke of course. I should say, for what it's worth, I

only use the car once a week at most.

 

John

[Ashley James]

John

 

My Bristol 400 is like that, in that you have to manually operate the fuel pump to start the car if it's been left for more than a day, but it doesn't need the choke to keep it going, so I think Phil's car is running weak and needs the Carbs setting correctly.

 

Ash

[ianc]

Whilst a correctly adjusted points system should work quite well, an electronic system eliminates the vagaries associated with the points themselves, which will gradually deteriorate and be eroded away from the moment that you start to use them. In addition, the heel, which operates the points, also wears away, further changing the timing.

Hence, I use an electronic system because it really is a case of fit and forget - no adjustment needed once set-up, preferably on a rolling road. As it happens, mine is a Newtronic (Piranha) system, and it has been on 4VC since 1993.

I would imagine that all electronic systems assume negative earth - but I am sure someone will tell me otherwise!

Ian Cornish

[BrianC]

Rather than opening the bonnet and manually priming with the pump lever (and getting covered in oil, etc), try turning the engine on the starter for about 10 seconds before pulling the choke out. This tops up the float chambers without flooding the engine. However, you should only need to do this if the car has been standing unused for a time. Properly set up, it should start almost immediately.

Edited December 31, 2010 by BrianC

[Dick]

My 3a also seems to empty it's float chambers after a week or so....there is no apparent leak so it must be evaporation.

 

I too had a Bristol many years ago...I seem to remember that it had a cable attached to the priming lever of the fuel pump so that it could be operated from inside of the car.....might try to conjure something up on the TR....then again I have put up with it for nearly 40 years.

 

I bought my TR as cheap transport (£230) early 70's, whilst the Bristol was off the road having an engine rebuild and respray. The Bristol got sold a year later for £600 and the 'temporary' TR is still here.

 

The Bristol was a great car...wished I still had it as well.

 

Dick

[Ashley James]

My 3a also seems to empty it's float chambers after a week or so....there is no apparent leak so it must be evaporation.

 

I too had a Bristol many years ago...I seem to remember that it had a cable attached to the priming lever of the fuel pump so that it could be operated from inside of the car.....might try to conjure something up on the TR....then again I have put up with it for nearly 40 years.

 

I bought my TR as cheap transport (£230) early 70's, whilst the Bristol was off the road having an engine rebuild and respray. The Bristol got sold a year later for £600 and the 'temporary' TR is still here.

 

The Bristol was a great car...wished I still had it as well.

 

Dick

 

 

Mine just has the little lever on the side of the pump. I've only had it five years, so a three year full rebuild and two years of holidays. It's a weird car!

 

Ash

[BrianC]

My 3a also seems to empty it's float chambers after a week or so....there is no apparent leak so it must be evaporation.

 

Don't believe it - Lincolnshire's not that hot!

It's probably a minor leak between float chamber and main body but you won't see it as it will then evaporate. Been there myself! At least it's an easy fix requiring minimal dismantling, cleaning and/or new seals, depending on which variety of SU you have.

[Dick]

Done the new seals a number of times....completely re-built the carbs...It's got standard SU s.

 

Other cars that I have owned had an SU electric pump....which always ticked on turning the ignition on after a few days...so the petrol that was in the float chambers must have gone somewhere on those.

 

Wonder why ST never spec'ed an electric pump as it was widely used on most 50's cars and ensured full carbs for start up.

 

You are right about Lincolnshire....... but after temperatures of - 10 and less we are now basking in a balmy 0 to -2 C with a refreshing light drizzle.

 

Dick..

[PhilJane]

Done the new seals a number of times....completely re-built the carbs...It's got standard SU s.

 

Other cars that I have owned had an SU electric pump....which always ticked on turning the ignition on after a few days...so the petrol that was in the float chambers must have gone somewhere on those.

 

Wonder why ST never spec'ed an electric pump as it was widely used on most 50's cars and ensured full carbs for start up.

 

You are right about Lincolnshire....... but after temperatures of - 10 and less we are now basking in a balmy 0 to -2 C with a refreshing light drizzle.

 

Dick..

 

 

Interesting stuff - thanks for all the comments and advise. On the electronic ingnition, the main advantage seems to be the consistency, durability and lack of maintenance, but assuming the ignition timing is correct, shouldn't be responsible for the poor starting. The general carb overhaul and setting up sounds a good idea and will attend to as the weather warms. Thanks also for the advice on fuel priming, the car is used infrequently so fuel in the float chambers may well be evaporating or leaking.

Happy New Year to all.

Phil.