1800: A bit of a hot starting problem

[skysurfer]

Having just replaced the old floats and seats on my SU carbs, the car is now running much better - particularly when starting from cold. However, on the last couple of occasions I've been experiencing a slight hot starting problem when the car doesn't immediately fire up. After a two or three minute wait it will then start okay. It must be a fuel evaporation problem somewhere so I've re-routed the fuel pipe away from the top of the crankcase. I'm also intending to replace the needles and jets at some point, but if the problem persists, is there anything else that can be done ?. I've also recently fitted a reconditioned water/oil temperature gauge which measures in fahrenheit. What would be the ideal running water/oil temperature be ?. The water temp on mine reads about 175 and the oil temp about 140 - but the latter hardly rises off the bottom of the gauge (my car has the oil cooler connected up). Is this normal ?. I did test the gauges in boiling water before fitting. Cheers. Paul

[amazondean]

The car should run ok if everything is set up properly, there should be no need to re route any pipes. I would suggest that the mixture is not set up properly or the ignition side either needs replacing or setting up properly.

[mike gilbert]

I agree with Amazondean, I've never heard of fuel evaporation problems on an S. I suspect your still getting too much petrol through on cranking when the engine is very hot.
It is normal for the oil temperature to hardly move off the bottom of the scale.
I've never understood fahrenheit

[skysurfer]

Thanks Mike and Amazondean. Once I've fitted the new needles and jets I think I'll have the car professionally tuned. Thanks also for the info about the oil temperature - I can only think in centigrade when it comes to liquids but, strangely enough, only fahrenheit when it comes to the weather !. I'm in that confused generation which experienced the switch from imperial to metric at school - although I should say that I did stop referring to 'new money' some years ago !

[Ron Kwas]

Paul;

Just what is your technique for hot-starting?

Cheers

[skysurfer]

Hi Ron

I just tend to crank the engine over whilst gradually depressing the throttle. I avoid flooring the throttle as this will cause flooding - although it might be worth a try if its a fuel evaporation problem. I think it may have something to do with the needles and jets so I intend replacing these and then getting a proper tune up. As previously mentioned, it's only a problem that lasts a few minutes and then the car fires up and runs fine.

Cheers

Paul

[Derek UK]

You'll get better results doing it the other way round. i.e. accelerator hard down then use the starter. Gradually lift your foot until it starts. As an SU has no accelerator pump like the Weber, Solex or other carbs you don't get extra fuel squirted in as you push down on the pedal. If all settings are good, a properly warmed up engine will usually start and settle at tick over with just a turn of the key, without touching any pedals.

[Ron Kwas]

Paul;

...just as I thought...you are not using the correct Hot-Start technique...some other problem notwithstanding (and I just don't believe "vapor-lock" caused by boiling fuel is occuring, especially in March!), flooring the throttle and cranking until it starts is the correct (and BTW owners manual recommended) technique, and Derek has covered the details!

Cheers from New England!

[222s]

Originally Posted by Derek UK

If all settings are good, a properly warmed up engine will usually start and settle at tick over with just a turn of the key, without touching any pedals.

Agreed - when warm, mine will fire the moment the key is turned.