1. 'bant

    'bant Loyal Comrade

    I have an intermittent starting problem, the engine starts fine when cold but can refuse to start when the engine has been running. Normally when the engine is properly hot but it can also happen after a five minute drive usually after it has been standing for ten minutes or so. Note it can happen on cool days 10-15'c so I don't think the problem is fuel starvation. However, a burst of volatile solvents in the air intake usually helps get the car going. The plugs look fine, gaps OK when I have taken them out during one of these episodes.

    I've done a minor carb overhaul which fixed another problem (I found, a sticking needle valve, wrong float level, leaking and missing gaskets between crankcase and carb). I also checked the fuel system, squeaky clean tank, good flow at the carb end, clean cup and gauze under the tank and the fuel when decanted into a jam jar is free of visible sediment. None of this seems to have helped the starting problem.

    I found a thread on a Dutch forum where the solution was to replace the coils and plug leads. This sounds like an idea to me because a) both items look like original equipment b) 2cvs suffer from hot starting problems when the coil is past its best. I'm not sure how points and/or timing could cause an intermittent fault but I guess these are worth checking. Any other possible things to check?
  2. turbofiat124

    turbofiat124 Loyal Comrade

    I have the exact same problem with all my carbureted vehicles when the ambient temperature get's into the upper 80s. Make a stop, come out 10 minutes later and crank and crank and crank. I found it best to just crank the engine over until it tries to start and then feather the throttle until it does start. Usually followed by a big puff of black smoke. DO NOT touch the throttle in the meantime otherwise it will definitely flood out and just make the problem worse.

    I wouldn't think it would be ignition related.

    I chalk it up to oxygenated gasoline additives which reduces the boiling point causing fuel to boil out of the fuel bowl and flood the plugs. I've tried running 100% gas (non E-10) with no results. I've also tried higher octane gas in my 68 Ford which seems to help a bit but not much. I added a cooling fan to my Yugo which blows outside air at the carburetor using a 180F fan switch mounted in the intake manifold which does help.




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    On my 68 Ford, I turn the air cleaner lid upside down in the summer which helps alleviate some of the heat from the carburetor.

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    One thing I have not tried is instead of just turning off the ignition to kill the engine, rather let it run out of fuel. Then come back and try to start it later. But I don't have a petcock valve on my Trabant anymore, my Ford has a mechanical fuelpump and my Yugo has an electric fuel pump. I guess I could pull the fuse out of the Yugo.
  3. 'bant

    'bant Loyal Comrade

    I read one of your previous posts about hot starting problems before I posted :) My problem affects only the Trabant. While the Dyane and my VW van need a fair bit of cranking when hot on hot days, they always start. They both have air cooled boxer engines which are prone to fuel vapourisation but seem to cope OK with Norwegian unleaded 95 RON fuel. The Trabant starting problem is intermittent (unlike the problem you have with your cars) and can occur on days when the temperature is 50-60ºF yet not be a problem when the car is hot on a summers day. It can happen after five minutes driving and not when the car has been driven for half an hour.

    The only choice I have as regards fuel is to buy whatever comes out of the pumps here in Norway which is 95 or 98 unleaded :) The Dyane gets 98 unleaded on hot days and long trips as it feels just a little happier with the higher octane fuel
    Last edited: Sep 7, 2015
  4. 'bant

    'bant Loyal Comrade

    The hot start procedure for both the Dyane and VW van is to floor the throttle whilst cranking the engine. Once they get going there is no need to feather the throttle :D

    If fuel vapourises in the float chamber then it is going to be forced through the main jet into the carb body and then go up out through the air filter (or maybe even back down the fuel line). If the carb is hot enough to vapourise fuel then the engine is going to be even hotter. The fuel is not going to condense on anything. Nicht wahr?
    Last edited: Sep 7, 2015
  5. turbofiat124

    turbofiat124 Loyal Comrade

    I'm not real sure what's going on with my carbureted cars. The fuel boiling and wetting the plugs is just a theory. I wouldn't think it would be vapor lock because all three cars have a different type of fuel delivery system and it happens with all three. Supposably an electric fuel pump is supposed to take care of vapor lock. And it's not the chokes either. My Ford does have an electric choke but my Trabant and Yugo have manual chokes.

    One thing I did find out. Back in the spring I was cranking the engine on a hot day and all of a sudden I lost all electrical power. Turns out the battery cables were bad despite testing good with an ohmsmeter (no resistance).

    Once I replaced the cables, the starter motor now spins faster and when I turn my headlights on, the alternator doesn't try to compensate and drag the engine speed down.

    Back in the winter I found the engine would not start without starting fluid around freezing. I thought perhaps the battery was going bad but I think it was the starter cables all along.
  6. 'bant

    'bant Loyal Comrade

    It looks like the work I did on my carb has helped hot starting a bit. I am still planning on replacing the coils and plug leads though.
  7. turbofiat124

    turbofiat124 Loyal Comrade

    It's been in the lower 70s this week and I made several stops yesterday with different time intervals and had no issues with hot starts. Mine always seem to occur when it hits the mid to upper 80s. Sorry for using Fahrenheit. I understand metric but when it comes to ambient air temperature, I have no concept of what Celsius feels like...

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