My 98 Explorer has been a rough start for more months than I can count now.
On the rare occasion that the "Engine" light comes on, the code has
indicated a lean let bank. Garage mechanic (none Ford dealer) thought it
might be a cracked intake manifold that, after warming for about 5 minutes,
expanded and sealed itself. Mechanic chased cracked manifold with no
results.If car is started for 1st time after sitting in very warm ambient
temps (>80) or in the sun, no prob with rought start.
Anyone out there with any ideas?
Sorry 'bout that....I must'a thought we were a bunch of guys sitting at the
What I REALLY should have responded is:
"I dont think so, Tim!"
While I would think a bad oxygen sensor might maybe cause that, possibly in a
rare case, someday, somewhere... it's WAY down the list.
The engine STARTS with the O2 sensors not in the loop. The ECM logic runs
from a map set when in full warmed up mode. An old sensor just switches
slower, allowing a wider swing in mixture.
Unless the sensor isnt switching at all, it's still setting about the same
average injector dose. If there's no code saying it isnt switching, then
it's hardly the problem
Actually the tech's idea made a lot of sense. It is likely a variable or
intermittent vacuum leak. Check for cracked vacuum tubing tees and
connectors... that Is a common problem
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