chris bowne

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 .

Chris Bowne
Stonington, CT

ted

It still sounds like a vacuum leak- My 95 had no metal tube you described,
the tube was plastic with the elbow fittings permanently attached; it came
as one piece from the dealer. Try taking the tube off the intake manifold
and plugging the manifold port; you don't want to drive it around like this,
but if you found the leak it should make it idle normally. In fact, you
could do this to anything connected to the intake manifold. Your check
engine light is no doubt the result of the rough idle, and will clear
itrself when you fix the problem. If you go chasing down a repair based on
a trouble code right now my bet is you will be headed down the wrong path.
My 95 is the same engine as yours, and has 122,000 miles on it; it has never
had any problem with IAC or throttle body. best of luck
Ted

I also still have my original IAC, TSP, and other sensors at 128,000
miles.

I also think OP has vacuum or air leaks. When checking for vacuum
leaks you need to check all vacuum devices also. I think a lot of
people miss this point. There is a vacuum solenoid on the EFE system.
It could be leaking (mine did). Your EGR Valve could be leaky. your
brake power booster, crusie control, or HVAC controls could leak
vacuum. You need to check all of these. A MityVac with a gauge is
useful for checking all of these things.

chris bowne

Thanks for the moral support guys - I have disconnected the PCV, brake
booster, and some of the EGR lines, of course blanking them off . Will keep
chipping away at it. My gut is that the EGR valve is intremittently
sticking open or has a small leak at all times, second gut is the evap
emission control purge canister being stuck in purge at idle. No cruise
control to worry about.

run a self test ya stupid fock

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