2003 Odyssey harder to start when engine warm

[Rick Fulmer]

I own a 2003 Odyssey with 105,000 miles. At 99,000 miles I replaced the timing belt, timing belt tensioner, spark plugs, antifreeze, and water pump. Just in the last month I have noticed that if I restart the van after the engine is completely warm, it takes an extra second or two for the engine to fire. I checked the EGR valve and cleaned the EGR ports. I have added fuel injector cleaner in two different tanks of gas. The idle of the engine is perfect. I have no engine codes. If I start the engine cold, it fires the first time every time. I can hear the fuel pump come on for a few seconds if I turn the key to on. Would anyone have an idea what might be contributing to this problem?

[New Dad New Van]

Check the Main Fuel Relay. It is under the Driver's side dash. Search for more info using "main fuel relay".

If you said that it was stalling at idle after starting then I would have suggested the Idle Air Control Valve.

[davedrivesody]

+1 I would just replace the main FI relay. It's a common source of startup problems. It's also known to fail in high heat. So it may not be the hot engine that's affecting it, but rather the heat under the dash from the heater.

You said you can hear the fuel pump, which means the FI relay is working. However, it may be opening during cranking.

If you are electrically inclined, you could remove it and open it up. The solder points can become weak over time. Resoldering them can sometimes revive the relay.

[Rick Fulmer]

Thanks for the information. I will look at it tomorrow.

[Rick Fulmer]

I resoldered the panel today. I will test drive it tomorrow.

Thanks for the information.

[Rick Fulmer]

I did take a hair dryer to the relay and did not experience much difference in the starting.

[davedrivesody]

Thinking beyond the FI relay, dirt in the throttle body could create a fuel-rich startup. Try pressing the gas a little as you start the hot engine to add air into the fuel mixture.

[Rick Fulmer]

Thanks, I will try it tomorrow.

[ImTheDevil]

Failing coolant temp sensors will create issues like this as well. A CTS is often under $20, and they'll fail eventually, so a pre-emotive change isn't a bad idea.

[Tony_SS]

Let us know what you find, mine has the same issue.

[molsoncanadian]

In your "Free-Time" I would just clean out some of the intake parts such as the IAC Valve; as it is known to cause problems with idle, also what Dave suggested; the throttle Body, you know just whatever you can get your hands on, get the gunk out of it. Also take a quick glance over your Ignition components, checking their proper operation, etc.
I personally would not replace anything, unless you know of the exact culprit.

Cheers man, It's irritating to have little but big problems like this.

[molsoncanadian]

Just Curious, Which Spark Plugs did you put into her?

[OdyinNH]

Just Curious, Which Spark Plugs did you put into her?

Good question.

[Our Odyssey]

I put NGK iridium and have also used Bosch Platinum+4's but saw no difference

[Rick Fulmer]

Pressing the gas a little did not help!