Re: 92 ford explorer
Take a look at the vacuum connections on the side of the intake
manifold, where the big hose from the brake booster attaches to the
engine. The connections incude a hose to the fuel pressure regulator,
a hose to the auto trans modulator, a hose to the HVAC, a hose to the
cruise control servo, and a plug on a spare port. Under certain
hard-to-start conditions, you may experience a mild backfire or pop in
the intake manifold that will blow one of the hoses or the plug from
the fitting. Once that happens, you have an air leak into the intake,
and the car will run rough, idle poorly, hard to start etc. Some of
the symptoms will diminish as the oxygen sensor warms up.
It's worth a look.
'92 XLT with plastic wire ties holding all those hoses to the vacuum
spider. Ask me why...