'98 Civic LX manual with 94,000 miles.
Engine dies instantly when you take your foot off the gas. Symptom
is intermittent, but seems to go away after car has been driven for a
while. Once the primary symptom is gone, if the car is left at idle,
the idle speed sometimes drifts around significantly.
Recent work, in the past 3 weeks (chronological order)
Alternator replaced by indy garage.
Plugs and air filter replaced by me.
Transmission oil changed by dealer.
Frayed wires under intake manifold repaired by dealer (fixed: erratic
speedometer, engine light, battery warning light inop)
Timing belt replaced by dealer. This included new water pump, 3
belts, coolant, valve cover gasket, etc.
[Symptom first noticed at this time (yesterday)]
New battery installed by me.
Q1. What is the correct idle speed? The tach is mushy at low RPM, but
it seems to idle about 500 RPM, occasionally climbing to 1000.
Q2. What controls idle speed? I've seen references to an Idle Air
Control Valve. Where is it and what does it look like? Can it be
cleaned? What is its expected lifetime?
Q3. Is there an idle air adjustment screw that sets a baseline for the
IACV? If so, where is it? Will I get in trouble moving it, as long as
I am careful to return it to its current position?
Q4. What else could cause this problem?
This is my daughter's car and I'm ignorant on Hondas and have no shop
manual. Any advice will be appreciated.