Em terça-feira, 3 de outubro de 2000 04:00:00 UTC-3, RD Thompson  escreveu:   
   > I have a Mercedes '78 450SL with CIS fuel injection that has spent   
   > more time sitting than driving (which is part of the problem, I   
   > presume).   
   >    
   > Anyway, my problem is hard starting when it is hot.  When the car is   
   > cold it starts with no problem..  Just cranks a bit and fires off.   
   > When it is hot and you let it sit for more than a few minutes, it has   
   > to crank a long time before it will start and run.  It gives a short   
   > burst as soon as you try it, but it is not enough to sustain it.   
   > After that initial burst, you need to crank a long time.  (Thank God,   
   > or whoever, for good batteries).  Lately, it seems to give a aarrgh   
   > aarrgh type of noise out of the engine compartment for a few seconds   
   > after it is shut off, but it does not last  long enough for me to pin   
   > down where it is coming from although it does seem to come from the   
   > passenger side of the engine compartment.   
   >    
   > I think my problem is a dropping of the fuel pressure (I have no gauge   
   > way of measuring it) which lets the fuel drain out of the lines and   
   > then it vapor locks leaving me to crank on the starter until the fuel   
   > pump can overcome that vapor lock.   
   >    
   > I have replaced the fuel pump and fuel filter.....no change....the   
   > pressure regulator in the fuel distributor...no change and put new O   
   > rings in the injectors.....ditto.   
   >    
   > My next attack will be on the cold start valve although cold(?)   
   > starting is fine.  Also, do the injectors maintain pressure at the   
   > injector itself or is it at the fuel distributor?   
   >    
   > What I need to know is if I am on the right track and if anyone has   
   > any other ideas.  Parts replacement at a hundred bucks or more for   
   > each part sucks.    
   >    
   > Except for the warm hard starting problem, the car is a joy to drive   
   > and really has comparatively few miles on it.   
   >    
   >    
   > Thanks in advance.   
   >    
   > RD   
      
   Hello,    
   I had the same problem with mini 1978 sl. Tried several alternatives, spent a   
   lot of money and the problem was a couple of minimum O rings that costed   
   nothing.   
   There are two major possibilities:   
   a) The retention valve on the fuel pump discharge   
   b) Problem that I had. On the CIS body (that where the 8 tubes goes to the   
   injectors, there is a retention/relief valve the lets the excess of pumped   
   fuel go back to the fuel tank, and regulates the injection pressure, and when   
   the engine is turned off    
   should close the fuel flow back to the tank and keep the system pressurized   
   for the next start. This relief valve have very small o rings that were bad in   
   my car. As I changed it, problem solved !!!! after two years of spending time   
   and money with a lot    
   of MB specialists.   
   Good luck   
      
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