94 Escort - Reading Intermittent Check Engine Light Codes-Still Stalling at Idle

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
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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

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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.
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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.
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On Wed, 22 Feb 2006 02:25:15 -0500, "Chris Bowne"

run a self test ya stupid fock
h u r c a s t
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