1600 vw motor hard to start once it's warmed up and sits.
Asked by 74bug Nov 12, 2014 at 01:30 PM about the 1974 Volkswagen Beetle
Question type: Maintenance & Repair
1974, 1600 vw w/pict34-3 starts easy when cold, runs very good. Will start up right after it's shut off, but after it sits for 5-10 minutes it's very hard to start and runs very rich. I have adjusted the valves, set the timing to 32 BDC, replaced plugs, rebuilt carb, float was fine. What's next, new carb? It runs great once it starts.
4 Answers
I would think carburator had time to set after warm,and fuel pressure up,the carb is flooding and that may be your issue,replace carburator.
It's the plastic piece that drops in below the fuel pump that guides the rod for the fuel pump. Once it gets hot it swells up and holds the fuel rod up. There is videos on YouTube how to sand that piece. I believe they call it vapor lock or something. Once you sand it should take care of it. I'm converting mine to a 3.5 PSI eltronic fuel pump with a safety switch on the oil pressure cause the local auto parts fuel pumps keep going out on me every few months due to the hot heat in Florida and the ethenal in the fuel messing up the digram.
EITHER VAPOR LOCKING ...OR TIMING SET TOO ADVANCED..IF THE TIMING IS TOO ADVANCED THE ENGINE WILL HAVE A LOPE IN IT WHILE CRANKING AND TRYING TO START , AFTER IT GETS HOT..
You probably don't have the original fuel pump. Replacements have springs that are too tight/strong thus create too much pressure. When you stop the car all that pressure pushes the fuel back down, past the needle and float into the intake manifold. The whole fuel system is flooded. "Plumb" a pressure regulator between the pump and carburetor. Throw in a pressure gauge too. Pressure should be about 2.8 lbs. Give credit where it's due: watch the linked video: https://www.youtube.com/watch?v=RqNkngDrlcI
