Hello.

My 1968 500f seems the struggle to start from warm. It does start eventually but can take a while. It turns over just won’t start.
I was wondering if it could be the fuel draining back but I’m unsure.

Thanks in advance.

Tim

Check valve clearances. These need checking regulary

Some bright spark told me that the Italians solution to this is to have a squeezy bottle filled with water in the car. When its hot and wont start, squirt cold water over the fuel pump.
Haven't tried it yet. I try to avoid getting my 500 wet at any cost.

Franko500 said:

I try to avoid getting my 500 wet at any cost.

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Good point My car is obviously rarely dry here in Scotland and always starts...hot, warm, cold or sub-zero. But it never did when the valves were going faulty so I agree more with Damian.

Franko500 said:

Some bright spark told me that the Italians solution to this is to have a squeezy bottle filled with water in the car. When its hot and wont start, squirt cold water over the fuel pump.
Haven't tried it yet. I try to avoid getting my 500 wet at any cost.

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My father had a Hillman imp back in the late 70's, 80's and early 90's... Little 875cc rear watercooled engine was suffering during summers so one time he proudly saw me his solution to overheating. He reroute the wiper flexi pipe from the windscreen direct into radiator fan. So next time water temp was close to 100 he activated the ''water injection" system, although no light speed achieved i remember the temp decreasing rapidly.
Back to the 500 as experts here mentioned try to adjust valves...

Thomas

Franko500 said:

Some bright spark told me that the Italians solution to this is to have a squeezy bottle filled with water in the car. When its hot and wont start, squirt cold water over the fuel pump.
Haven't tried it yet. I try to avoid getting my 500 wet at any cost.

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I'd go with what the Italians say...
after all they know the cars better than anyone in the UK....
and drive them in much hotter conditions.... and have done by the 0000s for years

The one time my previous engine actually stopped and wouldn't start because of heat was when I had the timing wrong, on a hot day, labouring in too high a gear up a straight, steep, main-road hill for a couple of miles.
You would have thought it had run out of fuel as there was no liquefied petrol at least as far back as the end of the flexible pipe before the pump.
I can't remember if I eventually pumped petrol from the tank or whether it came by gravity, but it means that it's possible to get a heck of a lot of vaporisation in extreme circumstances.

I'm sure the water treatment works, but I would be cautious about the possible thermal shock to components from a sudden dousing of cold water. I've also had problems in the past when water squirted in the engine-bay in that way for cleaning purposes has found it's way through the cowling and ended up blocking the carburettor jets making any kind of starting impossible.

Follow Sean's example and have no water near your air-cooled engine.

fiat500 said:

............... I would be cautious about the possible thermal shock to components from a sudden dousing of cold water. I've also had problems in the past when water squirted in the engine-bay in that way for cleaning purposes has found it's way through the cowling and ended up blocking the carburettor jets making any kind of starting impossible.

Follow Sean's example and have no water near your air-cooled engine.

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Well heaven forbid that any of these 500s or VWs or any other air-cooled car were ever used as daily drivers and driven in the rain or snow, they may have got cold water splashed on their engines...... I guess drivers must have fitted special splash guards or only driven when it was dry :devil::devil::devil:

Bigvtwin996 said:

Well heaven forbid that any of these 500s or VWs or any other air-cooled car were ever used as daily drivers and driven in the rain or snow, they may have got cold water splashed on their engines...... I guess drivers must have fitted special splash guards or only driven when it was dry :devil::devil::devil:

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I know what you mean.....

PT1_1337 by Peter Thompson, on Flickr

fiat500 said:

I know what you mean.....

PT1_1337 by Peter Thompson, on Flickr

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blimey.. I know that Ducati made outboard and inboard boat engines....
but a Fiat 500 boat!!!

Fuel vaporisation can be a problem when hot. For hot start I believe the hand book says no choke and to depress the accelerator fully. Then crank until it fires. Perhaps somebody with access to a handbook can confirm this?

I found one of my old books from 1983
The car doctor a-z symptoms causes cures available from Total garages.


If the petrol pipe passes near a hot part of the engine a vapour lock may occur, especially in hot weather, and will cause the engine to stop. The trouble will clear itself in 20-30 minutes if the engine is allowed to cool. Cold water may be thrown on the pipe and is quickly effective.


So there you go. The Italians are right about something.
Clearly an issue with older vehicles.
Maybe that's where electric fuel pumps have the edge. Especially with a return pipe. This would create additional flow and would presumably remove the vapour lock and supply the carb with constant fuel.