I need some help with a starting problem. 2002 CR-V LX 4WD. Stock.

I originally had 3 DTC codes. P0505, P1505 and P0113.

After troubleshooting those codes, I ended up replacing the IACV and the IAT sensor. Codes haven't come back on over a week now.

When I had the throttle body off to change the IACV, I cleaned up all the electrical connections with electrical contact cleaner (TPS, map sensor, etc).

Once everything was back together, I have developed a hard cold start condition. It starts fine once it's warmed up but it's a bugger to start when cold. I have to crank it a couple of times to finally get it to start but it does fire up eventually. Battery is only a year old and has lots of cranking power.

Once started in the cold, it seems to have no high idle. Even when I finally get it started on a -15c morning, the idle right after startup never seems to go above 1000RPM. Warm idle speed is fine around 750 but seems to not have a high enough cold idle.

Outside of the parts that I replaced as I mentioned above, I haven't done any other trouble shooting. Can someone point me in the right direction on where to start. Thanks.

 

I've still gotten nowhere with this. Still having to crank it over a few times for a total of about 20 seconds of cranking before it finally starts up. Sometimes it will start and die again right away before I finally get it going. I can hear the fuel pump priming when I turn the key on, I haven't checked the fuel pressure yet. No DTC's.

I'm going to remove the throttle body again this weekend and clean it out again, including the sensors.

Any other suggestions?

 

Did you follow this procedure with the IACV?

Was it a new IACV or a used one?

The IAT sensor could be the issue.

Might need to disconnect the battery for a while to reset the ecu...

 

Brand new IACV and brand new IAT sensor from Honda.

Removed throttle body (because of the IACV location). Disconnected all the sensors, etc and cleaned them up with electric contact cleaner. Cleaned throttle body with throttle body cleaner. Removed Iacv and replaced with the new one. Hooked coolant lines and sensors back up, bled the air out of the cooling system.

In the 1.5 hours to change the valve and clean the sensors, the negative battery cable was disconnected. This should have reset the ECU yes?

I'll try pulling the ECU fuse out tomorrow for a bit and see if it helps. I'll post my results.

 

It may take a full tank of starts to get the ecu to relearn.

Only other thing off the top of my head is a slight vacuum leak. Hmmm.

 

That crossed my mind too. I'll check for vacuum leaks on the weekend.

The idle relearn is a minor detail. Solving the hard starting issue is big thing.

 

I think I have it narrowed down to the ECT sensor (engine coolant temperature). Not sure if the sensor is bad or if I knocked a wire or the plug loose in the process of removing and reinstalling the throttle body. I haven't looked to see exactly where the sensor is located.

If I am correct, the ECU reads the temperatures from the intake air temperature sensor and the ECT sensor and based on those readings, it knows how much fuel to send to the injectors which clearly aren't getting enough fuel on cold starts since I need to press the gas pedal a bit for a second or 2 to keep it running on a cold start and I don't get a high idle.

Why do I suspect the ECT sensor? I worked a 12 hour shift at work today. The temperature was around -2 c (28 f). I parked it at 8am and didn't get back into it until 8pm. Fought with it once again to get it started and 2 seconds after it was started I noticed the temperature gauge was already 1/4 of the way up. There is no way it's warming up that fast! So I assume because of an ECT issue, the ECU thinks the engine is warmer than it actually is, which is sending less fuel the the engine than what is needed to get it running.

This is what I'm leaning towards. Does that make sense to anyone else?

With all that said, on to the temperature gauge. Where is this information read from? Is it the ECT sensor reading that is displayed on the temperature gauge or does it come from somewhere else?

 

ECT sensor was the culprit!

Swapped it out this evening. Works like a charm! Bit of a pain to get to but overall a pretty easy job.