In my ongoing struggle to solve my rough idle/stalling problems with my 94
1.9 L Escort, I have been seeing intermittent Check Engine lights (CELs)
that come and go whle the engine is running. They will last from a few
seconds to twenty or thirty seconds, but never lock in. They usually occur
while I am underway, with no accompanying otherwise observable symptoms of a
problem, i.e engine performance does not seem to change when the CEL is on.
It seems that the CELs tend to clear on acceleration, but not 100 percent
certain of that yet.
I do have a code reader for this (pre-OBD II) car. Are the code(s) that
cause these intermittent CELs stored so they can be read after the light
clears, or are they only present when the CEL is locked on? (Obviously hard
to do while they are occuring). If I shut down the ignition during a CEL
event before the light clears, will I "catch" the code?
Maybe my best bet is to connect the reader, and try to catch the codes
during the CEL events while attempting to maintain idle with the car parked?
With new IACV, TPS, and O2 sensor, still getting the rough idle/stalling.
Appears somewhat intermittent - behaved pretty well on drive to work
yesterday morning (mostly highway driving for 20 minutes). It nearly
stalled once, but generally held a fairly steady 900 RPM idle on its own
without any operator intervention. Last night though it started acting up
badly during in town driving and it was tough to keep it at idle at all
without constantly blipping the throttle. BTW, there are no indications in
the exhaust of soot or gas smells, or excerssive water vapor or anything
else abnormal. The intermittent CELs do not to seem to track with when the
idle goes to cheese. And the idle is bad only after warm up when the engine
managment system goes "closed loop" and idle drops off the higher "warmup"
idle of 1500 to 2000 RPM .