Re: wont start when hot

["luis" <luis@lumina.ucsd.edu>]

My experience has been that when a car with KE Jetronic (CIS) fuel
injection does not start when warm or cold it does not because the
injection system is leaking pressure after engine shutdown. This
lower pressure alows the gasoline to boil in the fuel lines,
allowing the formation of bubbles that block the flow of fuel
through the lines when someone attempts to start the car after
it has been sitting warm for a few minutes to hours.

When my 4ksq had this so-called 'vapor-lock' problem I immediately
suspected the fuel-pressure regulator, but the many responses I got
here made me check other injection components for pressure leaks.
Needless to say, I wasted my time and money doing so, and still
had to put up with the problem for months. Finally, when replacing
the starter I picked also from the junk yard a fuel-pressure
regulator from a 89 VW fox (since both cars have the KE J). Since
nothing else had worked until then I thought "what the hey" and
replaced the regulator. When I took the old one out, very cloudy
gas poured out of it, as if something had disolved inside. Even
before I put the new one in I knew that it had to be that because
the gas looked so cloudy. And indeed that solved the problem, for
good. The cloudiness probably had come from the diaphragm partly
disolving because of some California mandated gasoline sometime
during the previous ownership. The guy told me that it had had
the no-start problem for six years before he sold it to me!
Mechanics and all the other things everybody wanted me to
fix or replace cost in the 1000s of dollars; the used, but good,
fuel pressure regulator from the fox cost $6.50 and 10 minutes
to replace.

I advice you to do likewise. You will almost certainly fix your
car, and for what price! If you need help identifying the
regulator, please let me know.

HTH,

Luis Patino
'85 4ksq still going strong