p0505 on a 2000 Pathfinder

[esprit]

Hi folks, longtime lurker needs some help here. My 2000 Pathfinder (especially when the engine is hot) will struggle to start. It cranks, but will catch weakly, like it's missing, and struggle to stay running until I give it gas a few times. It shows codes for p0505 and p04440. I've had the p0440 for a long time (despite replacing gas cap and evap canister) so I ignored that.
For the p0505, I read a bunch of threads here and elsewhere about the 'dreaded' IACV which when it goes bad will fry the ECM. Now, I smelled an electrical burning smell the other day when I was struggling to start the Pathy, and so I was afraid that was the ECM. I took off my lower dash today and got it out to check.



I'm not seeing anything burnt-looking on this board. That makes me happy but confused. From what I have read, if it was the IACV, and I continued to drive it (several times), then the ECM should be burnt. So what's next? Do I focus on hoses? Do I try to take the IACV out and test it? I have no idea what I'm doing.

[04pathse]

Yes it wouldn't hurt to take a good look at the hoses particularly intake hoses.

You could try cleaning the IACV with throttle body cleaner only, there are several youtube videos on how to clean an IACV

It is possible for the IACV to be faulty and not take out the ECU.
This is an easy way to test the IACV: Start by clearing the fault codes. Then unplug the IACV and start the engine (this may cause other IAC codes to set. Just ignore them for now). If the P0505 code doesn't reset, then you likely need to replace the IACV.

If the IACV is found to be bad, you can pick up a new Hitachi IACV on eBay for around $100 shipped.

[esprit]

Thanks 04! This may be a stupid question, but can I start the car (to do the test you suggested) without putting the ECU back in? I'm kinda paranoid that it will burn out at some point if the IACV is bad, after reading all those stories. Is there anything else that would explain a burning smell accompanying the p0505, or maybe that's unrelated?

[Buzzman]

Just to clarify, is your Pathy equipped with the 3.3 or the 3.5 engine?
The 3.5 didn't show up until the 2001 model year.
The whole IACV, burning ECM stuff is only happening on the VQ35 engine.

As for starting the engine without the ECM in it?. Uh, I don't think so.

[esprit]

It's definitely a 2000, which means the 3.3. I didn't know the burning was limited to 2001+...I guess there's a lot of confusion/disinformation sometimes when you're reading so many threads with so many posters.
That makes me feel better about putting it back in. I'll look at the hoses some more tomorrow, and see if I can test that IACV the way 04patse suggested. Another thing I've seen mentioned is the "MAF sensor"? Maybe I will look into that, too, and go buy some kind of cleaner. It would be awesome if it was just a dirt issue.
Thanks for answering my dumb question, I had a feeling it was ridiculous just based on what little I knew about the ECM/ECU but like I said, I have no idea what I'm doing and just trying to learn as I go.