starter momentarily engaging

[daver clasper]

Hi every one

When starting my Vitesse from cold I crank the starter for a few seconds to build up some oil pressure then pull out the choke and it fires up.

Before I can do this though, when I first crank the starter without choke, it seems the car tries to start for a second and then the starter motor then disengages.

Just trying to minimize wear on the flywheel ring gear mainly, so wondering if anyone has ideas why this happens.

Any advice as always much appreciated.

Cheers, Dave  

[dinger]

Starter solenoid has burnt contacts

[ferny]

The car tries to start and the motor disengages? Seems normal.

[daver clasper]

Hi and thanks for replies.

What I'm getting at, is why the car initially tries to start for a second with no choke, even on cold mornings.

It does run sooty/rich plugs at idle, could it be that.

Cheers, Dave

[Casper]

Unburnt fuel drawn in due to continued rotation after the engine is switched off and unable to evaporate from all the cylinders as the vales are closed?

A bad habit with a bad starting car used to be to rev the engine before switching off in order to achieve this effect.  Not good as it washes the bores.

C.

[RobPearce]

It's quite normal for carburettor engines to be able to fire once on the residual fuel in the manifold, even without choke. With an inertia starter this usually results in the starter disengaging. If you had an electric pump and pulled the choke full out straight off, there might just be enough fuel drawn in during that first fire to provide enough of a second fire to actually start the engine, but if you prefer to "build up some oil pressure" then that's not what you're after.

[Clive]

The solution is to put a switch in the ignition circuit, so it won't fire until pressure has built up.
I wonder if there is a oil pressure switch that closes the circuit when up to pressure, that would be a better solution.

edit. it could be done using the existing oil pressure switch and a normally shut relay (or a changeover one)

[RobPearce]

Depending on how good your engine, filter and battery are, you might actually struggle to get oil pressure before starting!

[A TR7 16V]

Quoted from cliftyhanger

The solution is to put a switch in the ignition circuit, so it won't fire until pressure has built up

I'm not sure forcing it not to start till oil pressure's up is ideal. I suppose you could fit a defeat switch in parallel (with a relay in the ignition feed that's open till the oil light goes out). But if the charge in the battery is low, you could blow it all by the time you've realized you wanted a quick start. I've done that by waiting for the oil light to go out before pulling the choke out, as you do.

As to firing a bit when cold but with no choke: Might excess fuel when starting be connected with slightly leaky float chamber needle jets? I'm wondering if there's enough fuel in the line above and/or enough residual pressure to overfill the float chamber and lift the level above the top of the main jet; especially, if the tickover is set a little high. You might even be able to see something by removing the filter when cold and looking if there's fuel on the venturi steps.

It's probably not that, but it's easy and relatively cheap to try.

Graham

[daver clasper]

Thanks a lot for all your replies, all interesting stuff.

Maybe I'm a bit too concerned by it. It's my only vehicle and used for work, so could do without the hassle of ring gear wearing as a bit of a job to replace if gets unreliable.

I don't know how tough or lasting they are.

Cheers Dave

[Pete Lewis]

Dave to avoid excessive ring gear wear , i would stop faffing about oil pressures on start up.it was designed to run like this as thats the type of filtration in its day, you could fit a spin on filter to retain some oil from  overnight drain backs
,just remember they have lasted 40 + years with this myth
do what the hand book says ,, jump in , pull choke , crank her up  , let it idle  for a few seconds,  doing what you do will cause far more starter and ring gear wear than any low oil pressure will give you

just dont fire it from cold and rev the nuts immediately it fires ,,just give it a few seconds to  'wake up'

Pete

        

[Scimher]

...Good advice, Pete. You could always put some 'Slick 50' in, Dave - or an engine 'molyslip' treatment to offset any wear at start-up.  I've done 23k mileage in my Herald & religiously wait a few seconds for the oil-light to go out to stop/reduce any 'death rattle'!!  

[Dogsbody47uk]

Quoted from Scimher

...Good advice, Pete. You could always put some 'Slick 50' in, Dave - or an engine 'molyslip' treatment to offset any wear at start-up.  I've done 23k mileage in my Herald & religiously wait a few seconds for the oil-light to go out to stop/reduce any 'death rattle'!!  

Ditto.