QuestionQUESTION: Hello.I have a Volvo s80 SE 2001 2,9l.Every time it runs great,except for very
hot summer time,when i am in a city.when the car is cold,it starts fine.after i
drive arround and it starts to get hot,it suddenly stops and doesn't want to
start any more.it turns just fine,but no ignition.it's like there is something that
stops the gas,and the car can't start.if i let it to cool down for half an hour,i
hear a click sound comning from the etm and after that the car starts
normally and runs untill it gets hot again.to be precisse,i must tell you that it
only happened inside very busy city,and once on a mountain road while
driving hard.I could never make it stop while i was at a dealer,so they could
see if any codes apear.in the dashboard every light is normal.No fault
lights.My idea is it could be the Magnetti Marelli ETM which i heard has a lot
of problems,or one of the oxygen sensors.What do you think?
Many thanks!
ANSWER: Constantin, is this a US build car? I think not if it has the stupid Marelli setup. That could be your hot soak problem. Check for the presence of spark when it will not start. My othe rguess would be the fuel pump relay or pump itself.
Mark
---------- FOLLOW-UP ----------
QUESTION: I bought the car from North Carolina,so it may be US built.I think that if it
would be the fuel pump i would have problems other times also,not only
inside city on very hot weather.Because it only happened in city and once on a
mountain road i was thinking it could be an oxygen sensor malfunction and it
would cut off the gas.I don't know exactly what in the car can control the gas
flow,or the gas pump,to stop it from runing.Any guess?
Thanks again!
Answer Here's what can happen. A worn fuel pump starts to generate excessive heat at the head.(Discharge end)Long running magnifies this until the fuel begins to boil. (Percolate) This air fuel mixture cannot be pressuriaed to minimum fuel system specs. and the injectors will not fire(spray). It's not fluid anymore so the pump is not strong enough. When everything cools down, it works again. Then the cycle repeats.Make sense to what you are seeing?
Also higher altitudes aggravate this condition because the fuel can boil sooner.
Mark
