Wont start when hot

[knockdolian]

Hi all, My car is getting worse. When warm, hot if I stop the car it wont start again until cool. The other day I met a chap who said they all do that vapour lock ??? Is this correct and can it be sorted. never had this issue with any of my other cars with SU's on
Thanks

[Galileo]

Could be a vapour lock but that's usually caused by overheating, and petrol boiling in the pump (if engine driven) or pipework, but you said it happens when warm too. Not necessarily likely to be just a fuel related thing, as it could easily be a failing coil or aftermarket electronic ignition for example. Anything changed, even if not obviously related, before this started happening?

[Toledo Man]

This is a problem with modern fuels which burn hotter. I posted on your wanted thread. You need the shield the carb from the exhaust manifold to keep the temperature down.

[Mad Mart]

Could well be the coil. Is the coil getting really hot?

[Edin Dundee]

Could also be a too rich mixture, although why would it have got worse? Foot to the floor when cranking if the engine's hot to allow more air in.

[alolympic]

I had the same issue with my car earlier this year. Lots of head scratching and suggested problems on here.
The car is running rich but I cured the hot start problem by closing the plug gaps a bit.

[RobSun]

My Dolomite 1300 had exactly this problem earlier this year. You do not state if the car is a 1300 Dolomite or FWD in your wanted add, but mine proved to be the coil failing and I and others thought that it was fuel vaporisation. After posting on here it was suggested that it was most likely to be an electrical problem and once the coil was replaced the issue stopped.

Someone better at computing poss. Toledoman may be able to link this post to my old post.

Bob

[Toledo Man]

The thread in question is HERE

[Jon Tilson]

I have hardly ever known a dolomite to suffer from fuel vapour locks when hot.

If this is an ohv twin carb the first thing to check is the carb heat shield if you suspect this.

If its a slant engined ohc car then I would suspect the ballast bypass feed is going amiss at the starter connection.

Jonners

[knockdolian]

Thanks for the reply's, its a 1300 RWD 1980. Ill check the coil when it happens next, weaken the mixture and shield the carb. Watch this space

[Jon Tilson]

If it wont start when hot you could also try pulling the choke.
You may have a waxstat pellet that's expanded and weakened it too much. Pulling the choke may
seem counter intuitive but it drops the jet and richens the mixture again...

Also look for pin holes in all rubber sections of your fuel line, which could be allowing your fuel pump to suck air.

Jonners

[AlanH]

If it's got waxstats it's worth doing the 2p conversion.

There is a thread on here somewhere with some illustrations.

May or may not cure the problem but it's a quick job.

[Toledo Man]

Alan, it only has one carb (the car's a Dolomite 1300) so it would only need one penny for the conversion.

[geeksteve]

Alan, it only has one carb (the car's a Dolomite 1300) so it would only need one penny for the conversion.

Think it's 2 x 1p coins per waxstat actually

Steve

[knockdolian]

I replaced the jet about a year ago for the non wax stat alternative. I cant remember what the number is.