I've just completed a 1,300 mile trip from CO to CA. Oil was done before trip, plugs still have life and oil levels check out. After day one.. car still ran fine. After day two and upon arriving at my destination the car began to have jumpy idle and would die if not in gear.

It has been pretty hot here, including the day I got in. I'm assuming my three year old Optima red top wouldn't be the culprit. Again the car seems to drive fine when in gear only. All electronics work and the car starts up just fine - it's just when it idles that it has issues. Ended up checking the MAF and air filter - a little dirty, but nothing major. Cleaned both and reinstalled. Car still runs like crap. Just finished up replacing the front AF/O2 sensor per someone's suggestion. No luck. Could it be the IAC...or something else? I'm stumped.

 

Worth a shot. Clean the IAC and don't forget to replace the gasket. Do you have a cel? Seafoaming the car wouldn't hurt as well.

 

IAC pulled and cleaned. Reinstalled and still having the issue. The odd part is I am not throwing a CEL at all...

 

Is there any power loss or bogging?

 

That's the weird part - when it's in gear and throttle is being applied it seems to be running normally. The problem is only happening when out of gear or idling.

 

I too would like to know this. Happened to me today while driving around the block without an air filter on ( yeah, i know, stupid).
died when it was out of gear.

 

Ended up bringing it down to a local shop. Ran diagnostics and did some poking around. They came up with the decision that the stock BPV was shot (bad spring?). Hmm...

 

Would that cause more air to enter the engine?

 

hmm that's real weird. Haven't heard that one before. Well I mean it can happen I guess, stay stuck. Just get another around the forums or on craigslist. They go relatively cheap. I would NOT suggest a BOV as a alternative solution. Good Luck.

 

Seafoam car.

1/3rd in BPV or BOV vac line (I used a funnel and a cup after pourin 1/3rd into the cup)

1/3rd in oil

1/3rd in gas

Let it sit for 10-15 minutes.

Rev car in neutral for about 5 minutes at various range (3k to 5-6k) leave it at a high rev every now n' then, dont just rev n' let it drop. And watch the white smoke leave ur car

If ur going to put it in your oil, you will probably want to change your oil after ur done. Dont drive around afterwards without changing ur oil.

I did this and my idle went from almost dying/hard idle to a lot smoother n' calm idle.