95 LS sometimes has trouble starting

[Adam]

Hi folks. New to the forum (although I registered a long time ago) 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.

[jpeso23]

you posted this on honda tech right

[rewsintegra]

sounds like the ignition switch to me. before you go buy a new one, take it apart, there is sometimes a carbon like buildup that gets on the conduction point. scrape it off. put it back in, if it starts normal then that was the problem, if not you may need a new ignition switch all together.

i am about 90% sure thats your problem though

[Adam]

Originally Posted by jpeso23

you posted this on honda tech right

Yep, trying to get help anywhere I can!

[Adam]

Originally Posted by rewsintegra

sounds like the ignition switch to me. before you go buy a new one, take it apart, there is sometimes a carbon like buildup that gets on the conduction point. scrape it off. put it back in, if it starts normal then that was the problem, if not you may need a new ignition switch all together.

i am about 90% sure thats your problem though

That makes sense, I know the contacts you are talking about. I can probably lightly hit them with sandpaper. It seems like the issue would happen all the time if the contacts were corroded though.

[rewsintegra]

thats what i thought too, but mine only happened every once and a while

[Adam]

I ordered a new fuel pressure regulator. Sounds like this may be the source of my issues.

[Adam]

Hopefully this helps someone in the future..

I replaced the ECT Sensor and my problems are solved. I believe my old one thought the car was cold when it was actually warm, causing the ECU to flood the engine with gasoline resulting in difficulties starting.