My 2000 is having an issue now with stalling out at idle, but only when cold. But I can keep it running with a little gas. When the car warms up after 10 mins of driving or so, it holds fine at idle without stalling. I am getting a P0505 code. I replaced the MAF sensor and did the idle relearn procedure, but the issue persists. I used up about 1/3 of a can of carb cleaner and didn't detect any vacuum leaks.

I did have idle stalling issues maybe 7 years ago or so, but then it stalled out all the time at idle regardless of how warm the engine was. I replaced the IACV then and the issue resolved.

Question is, do I need to replace the IACV again or are there any other things I should troubleshoot first?

Thanks

 

When turning your car on and it's running, what RPM does it idle at? If this is initially too low (under 750RPM) it would be cause for the engine to stall. If it's under that 750 point, you can easily adjust the butterfly for the idle near the throttle body. Otherwise my initial thought was a failed MAF, but you replaced yours. The next second guess is a failing IACV.

 

I can't really tell - it never goes to idle - if there is no gas, then the RPM drops down to nothing. When the engine is warm, it does seem like it was between 750 - 1000, depending on the day (i'm going off of memory now).

I pulled the throttle body / IACV out last night to take a look and clean. It wasn't that dirty, or certainly not compared to the last time I replaced it. I will reassemble this afternoon and go for a drive to see if that cleared it up and/or see what it is idling at.

Any other thoughts or tips on what I should be doing while I have it out? Understanding that I will have to take it out again if I need to replace the IACV.

Thanks again

 

While I'm not entirely certain if ignition coils could cause this, I'm leaning towards your MAF sensor with this. Unless you have a severe leak which you scoured for and did not find, a very faulty MAF could cause this. IACV would still have the car start, but either idle very high, or have your RPMs jump like crazy. I see you also replaced the IACV several years ago. How long was that in bad shape before changing? This would cause your ECU to fry or become damaged, so maybe it created a lingering issue for your ECU that is now showing itself?

 

The good news is your car starts. The issue is keeping it on, so the MAF would be the cheapest to check before delving deeper into this. You very well may have purchased a faulty MAF -- **** happens.

 

Thanks for the feedback. For an update, I put everything back in last night, did the idle relearn procedure, etc.. Problem still persists when cold. With the engine warmed up, it is idling at around 500. I have a manual, so I understand it should be idling closer to 625-650, rather than the 750 for autos? This afternoon I will try to adjust the throttle up and see what happens.

FYI - for some other background, I did replace the MAF last week, but I wasn't positive that the old one was bad. What are the odds that the new one is fault too, but only for the same issue?

For some further background, I dug back through all of my old emails and found that I bought the IACV in Nov 2010, so I guess that's when I replaced it; I thought it was a few years later than that but I guess not. I had been having the stalling issue for at least a month prior to doing that, so I actually got quite good at managing it while driving the manual. I remember pulling the ECU at that time, nothing burned out then. Given that this was 2010, I have certainly driven it quite a bit since then, including driving back and forth between Chicago and Detroit every week for about 2 years, so I would assume anything residual ECU issues from then would have popped up before now. Original (bad) engine coils were replaced in 2007/8 or so.

The car was also rarely driven since the end of summer, 2016. After having a baby, we needed a car that my wife could actually drive, but only had 1 parking space in Chicago, so the Maxima was semi-retired to my parents' place out in the country. We moved out to Salt Lake City last September, where we can have multiple cars, so I started fixing things up last summer. Notable repairs at that time included (original) fuel pump and battery replacements. Then I replaced the (original) starter two days before driving it 1,400 miles to SLC. I feel like the idle problem probably started right around this time, because prior to replacing the starter and battery, I had to jump it and let it run for a while a few times, while trying to figure out if I had a battery, starter or alternator issue. As I said, I was still on my original 2000 starter, alternator was last replaced in 2015.

During the polar vortex in Feb 2019, some mice did get in and cause some damage. They also chewed through the wires to my wiper blades, so it might be possible that they bit into something else somewhere that isn't immediately visible.

 

Try voltage testing your TPS check for 5v reference and between 4.5 and 5.5v signal.

 

I will try that out - thanks.

Also, one more thing I forgot. In addition to the P0505, I am getting P0110 and P0135. 0110 has been there for 6 years, but the 0135 not. Any chance that could be causing this? What I read on that so far suggested otherwise, so I figured I'd resolve that after dealing with the idle issue, but it is certainly something noteworthy to mention.

 

P0110 is air temp sensor,p0135 is B1S1 Is right in the back of the engine close to the bulk head these combined could absolutely cause this air temp is not correct combined with skewed fuel air mixture and you also say P0505 the ECU is struggling to find good references it could be a plugged cat causing this because its telling you its not breathing right.

 

she cant relearn the idle if she has these codes showing any way.

 

Thanks again for the input. The 02 sensor replacement has been reprioritized but the repair is on pause because Autozone and the others want $100+ for a replacement upstream (right) sensor, so I'm waiting for the part from RockAuto in the mail.

I the meantime, I've reassembled everything except the air intake scoop and all of the other junk before the air filter. Interestingly, I have noticed that instead of taking ~10 minutes for the engine to warm up enough, it now only takes ~2 minutes of driving to get to that point.

 

Just wanted to add another update - the old O2 sensor was fused to the bung in the exhaust when I removed it, so I had to order a replacement bung (I opted for a weld-free strap-on model, since my welding skills suck even when I do have room to work). Anyway, that showed up on Saturday, so I was able to put everything back together. With the new sensor in place, the P0135 code is gone, but I still have P0505 and the P0110.

Idle issues still as they were, with it taking a couple of minutes to warm up and then no more stalling

 

Also check your water temperature sensor wiring and sensor it may be faulty.