95 LS sometimes has trouble starting
Hi folks. New to the forum and hope you don't mind assisting! My car is a 1995 Acura Integra LS with automatic transmission. The problem I'm experiencing is that the engine will require 8-10 long cranks before it starts after it sits for 1-2 hours. Nearly every day, I come home at 5PM, if I try to start the car at 7PM it will act this way. When I go to work in the morning and leave work in the afternoon it always starts right up. This is what I have done so far, along with additional information:
# Replaced main fuel relay
# Replaced fuel filter
# Replaced purge control solenoid and filter
# Checked fuses (none are blown)
# Battery voltage is ~12.4 sitting and ~14.4 running
# Idle is perfectly 750RPM at normal operating temperature (no surging, fluctuations, lag, etc)
# Replaced spark plugs, distributor cap, and rotor
# Spark plug wires have ~30,000 miles on them
# Spark plug wires measure below 1300ohms impedance
# Entire distributor assembly was replaced ~12,000 miles ago
# Cleaned battery terminals, clamps, and grounds (chassis, valve cover, radiator)
# Timing was set to stock 11 months ago
# Coil measured 0.8 and 18.2k impedance (within the acceptable range)
# CEL acts normal (comes on for two seconds then turns off)
# When the car has trouble starting, audibly the starter sounds like it's functioning properly (no clicks).
# In the past 10 months, 4 or 5 times the engine has died when I shift from Park to Reverse. It easily starts back up. I'm not sure if this is related.
When testing the Ignition Control Module (ICM) resistance at wires BLK/YEL and WHT/BLU with GROUND I'm seeing 0.0 rather than 12v battery voltage. This was measured with the coil removed. For a ground I tried all different places on the chassis, valve cover ground wire, etc. Would this indicate a faulty ICM or a bad ground? Keep in mind the car normally starts 90% of the time, but does not like starting if it has been sitting for a little while - heat related? I'm running out of ideas and this is driving me insane.
I opened up the ECM and it looks perfect. No leaking capacitors or anything. I also have high resolution ECM photos if requested.
At this point I'm not sure if it's the ICM, Ignition Switch, Starter, or something else. Thanks in advance.