Tips on curing vapor lock?

Rokas Reipa rokas at
Wed Feb 12 13:31:39 EST 2003


I had the exact same problem with my old 86 5kcst. It only happened in
winter with oxygenated gas and it drove me crazy. It should be mentioned
that I did not have the injector cooling fan operational at the time; other
afterrun components would function. I did the exact same thing Stephane
described(wiring a button to the cold start valve) and it worked
beautifully. The downside to this was that when coaxing the hot engine to a
start via the button, the car would produce a huge cloud of smoke. ANd it
makes a wonderful anti-theft device, just as Stephane described. HTH,

93 100s

> > I've tried a bunch of things to relieve my vapor lock and it's still
> > bad. I keep fumbling with the residual pressure valve, but the fact
> > of vapor lock still remains. In city driving, it's very noticeable,
> > but mostly after sitting for 1/2 hour. I have to use "special"
> > starting procedure to get the car running and purge the fuel ines
> > with cooler fuel.
> >
> > I have my injector cooling fan running. I do use a lower temp switch
> > mounted elsewhere. Afterrun works. The rubber boot for the hoses is
> > there. I wrapped it with foil tape. It helped some, but not that
> > much. Anyone been here before and what did you do? I'm going to try
> > and shim the lines from the intake manifold with some silicone
> > strips to see what happens. I can raise the residual pressure, but
> > that'll leave me with harder starting, but the + is that it'll start
> > every time.
> >
> > Any ideas?
> >
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