idle increase on parking?

[Green1]

The last week or two I've noticed when I get to my destination and put the transmission in park the idle jumps from it's usual 600-700 rpm up to about 1000 rpm.
I can't figure out why, I don't remember this happening in the past, but it's certainly happening now. I've checked the "usual" culprits (A/C is off, manual throttle is disengaged) but haven't found any reason for this.

I guess I have 2 questions:
1) should I be worried, or can I safely ignore this?
2) any ideas on what could be happening?

[Schwa]

similar thing happens to mine when in park and I shut down all the electric loads, gets up to 1000rpm or so... I figure it has something to do with cold air and winter diesel, but who knows...

[MardyDelica]

Hi, sometime this thing happen mostly if the weather is cold it get gel, i does to me also, but next day its gone,
also check the leak of your pump & the throttle cable sometime it get sticky as where the weather is cold, otherwise no need to be concern, regarding this issue. used diesel lubricant as much as possible so the pump wont dry, as our fuel here used low surfur diesel.
Cheers;

[robinimpey]

I too have noticed this a time or two and haven't come up with a reason for it. I hate to say this for fear of jinxing myself, but I have not found anything quirky on my Delica at all so I figured it must be something that it's supposed to be doing. Is it possible that the Delica idles higher if the battery needs charging?

If anyone knows what the real reason is that this is happening let the rest of us know.

Thanks

[Schwa]

It's actually more likely that it idles high because the battery is charged (or like in my case I turn off electrical loads) since as far as I know the only thing that kicks the idle up is the air conditioning compressor coming on, and in my van I notice that with just headlights and the front fan on the RPM will drop from 1000 to 800 in neutral or park and then go down to about 750rpm once in drive.

[Nisseman]

The idle increase should be due to your AC pressure switch. Your AC will run when in defrost mode if your AC button is on. Try turning the AC off with the AC button and see if this eliminates your idle fluctuations. It is normal for the idle to ramp up with the AC on.

[Green1]

The idle increase should be due to your AC pressure switch. Your AC will run when in defrost mode if your AC button is on. Try turning the AC off with the AC button and see if this eliminates your idle fluctuations. It is normal for the idle to ramp up with the AC on.

In my original post I stated that I had already checked to make sure that the AC is off.

[BCDelica]

This happens to our two Delicas too, but only when they are running at full operating temperature on full diesel in the winter. Does not happen on WVO (anytime) and doesn't occur in the summer months. Idle does run a little higher on diesel, maybe 50-100 rpm's during past summers.

Would like it if one of those mechanics here could explain this phenomena. My stab in the dark would be some thing's going on with the IP and TPS?

[DelicaMark]

Safety in numbers right....this started to happen to me the past few weeks. Seems normalish judging by the other responses. I am leaning towards the winter fuel and colder temps. These seem like a common denominator with everyone here.

-Mark

[Schwa]

From what I understand, the winter fuel ignites easier but contains less energy per volume, colder air is more dense, so packing a bit more air in with easier to ignite fuel might explain it. I noticed when I refueled at Husky in Coquitlam the idle was higher than my latest tank that I got from Chevron in Aldergrove, so it seems to vary.

[Nisseman]

The idle increase should be due to your AC pressure switch. Your AC will run when in defrost mode if your AC button is on. Try turning the AC off with the AC button and see if this eliminates your idle fluctuations. It is normal for the idle to ramp up with the AC on.

In my original post I stated that I had already checked to make sure that the AC is off.

Yes I know but a lot of people assume that if they have their heat on the AC isn't working so quite often they don't consider the AC as a possibility. My RPM ramps up all the time and if I hit the AC button it cuts back. The winter fuel can't be an issue around my neck of the woods because as far as I'm informed they don't switch fuels due to our moderate climate. Besides, an rpm increase of 400-500 rpm just due to winter fuel? Sounds highly unlikely.
I'm not saying it has to be the AC, just suggesting the AC might be working without people realizing it.

[Green1]

I'm not saying it has to be the AC, just suggesting the AC might be working without people realizing it.

in my particular case I have tried both positions of the AC switch, AND my AC is currently physically disabled pending installation of a part. it's not the AC.

I am buying the winter fuel + cold air excuse though, it actually makes some level of sense, and it explains a lot.

[dharmadelica]

I'm having similar issues. As far as I know the AC is off and there is a click from a module somewhere under the dash. The RPM's will jack to between 1200-1500 for a few seconds and then, click, drop back down to normal. I'm going out to triple check the AC off, any other suggestions. . .

[Green1]

the click behind the dash really seems to point to the AC I would think... if you're positive your AC is "off", try with it "on" and I suspect you'll find it goes away (ie you may be mistaken as to which position is "on" vs "off" it is a rather counter-intuitive indicator...)