P0507 idle air control issue

abrad

Sr. Member
Joined
Feb 20, 2007
Messages
179
Points
18
Location
New York
Make
Honda
Model
Accord
Year
2004
Miles
225,000
Engine
2.4
Wife’s car, bought used (see earlier post!), have had it running now for 2 years.

Initially it had a code P0507, idle air control system rpm higher than expected. Read up on this, and apparently a very common occurrence is the IAC failure. I replaced that, and all was good - for awhile. Then it started up again. Idle will rev to upwards of 2,500 in park. This only seems to happen when it reaches half a tank of fuel.

I recently replaced the PCV as it was not the cleanest looking. I’ve checked for air leaks all along the intake by spraying carb/choke cleaner, no effect. Next up is to fix my home made smoke machine and see if anything shows.

Today it threw the code again. It seems to happen when it gets down to about half a tank. I put gas in, and when I went to clear the code, I noticed that one monitor was showing “inc” - catalyst monitoring. This hasn’t been reset in awhile, we just make sure the car stays above half a tank, and no problems. Could this be something with the evap system testing? Thinking maybe a valve on the canister not operating correctly? I know there’s ways of testing, but need to know if there’s a specific way for this car.
Thanks!
 

grcauto

wrench
Joined
May 29, 2014
Messages
1,034
Points
48
Can you look at FF?
 

grcauto

wrench
Joined
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Messages
1,034
Points
48
Look up the conditions needed to set that code and look at the relative PID"s and see if something pops out.
For example. I do not believe that code can set if throttle is not closed. Look at TPS. Should read closed.
 

abrad

Sr. Member
Joined
Feb 20, 2007
Messages
179
Points
18
Location
New York
Look up the conditions needed to set that code and look at the relative PID"s and see if something pops out.
For example. I do not believe that code can set if throttle is not closed. Look at TPS. Should read closed.
Ok, just get home from work, and the wife informs me the CEL is back on. Fuel tank is reading 3/4 tank. System status shows one monitor as INC. When I go into the I/M Readiness, Catalyst Monitoring is showing INC. the evaporative system monitoring is showing OK. Could this possibly be a catalytic problem???

Thanks in advance!

Here’s what shows on the freeze frame -
code is P0507
Fuel system 1 status CL
Fuel system 2 status - -
Calculated load value 49.8%Engine coolant temp 86°C
Short term fuel trim - bank 1. 17.2%
Long term fuel trim 9.4%
Intake manifold absolute pressure 50.0 kPa
Engine rpm 936 rpm
Vehicle speed sensor 0 km/h
Ignition timing advance for #1 cylinder 0.0°
Intake air temperature 28°C
Air flow rate from mass airflow sensor 45.12 g/s
Absolute throttle position 9.4%
relative throttle position 0.0%
 

grcauto

wrench
Joined
May 29, 2014
Messages
1,034
Points
48
Absolute throttle position 9.4%
relative throttle position 0.0%

Look at these when it's running OK and see if the match or are close.
 

abrad

Sr. Member
Joined
Feb 20, 2007
Messages
179
Points
18
Location
New York
TP 9.4%
TP_R 0.0%

What a day! I’m at work 2+ hours in, and the wife texts me that the car is dead, the door locks won’t open using the fob - she had to unlock the door manually! I get home, battery is reading 0.4 volts. Put it on the charger, then start looking for battery drain. Turns out she bumped the vanity light when putting her sunglasses away. Got the battery charged, car started right up! Yeah me - an easy fix for once!
Once I got it started, I let it run a bit, then checked for those numbers, they matched. Now what???
 

abrad

Sr. Member
Joined
Feb 20, 2007
Messages
179
Points
18
Location
New York
Is it running good?
Runs fine, until it acts up. Then it gets a revving idle. The wife gets all scared when that happens. Yesterday the code popped again, and it revved up and down a bit. She stopped at the store in the way home, and it ran fine.
 
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