2000 Frontier 2.4 2WD, Surging Idle.

[wingnut510]

OK gang

I know this is a real Noob question, I did a quick search, nothing that applied.

I have noticed a intermittent condition, of the idle surging between 1500 and almost 2000 RPM. The idle will eventually settle down, sometimes to the normal 750-800 or so, and sometimes it will settle around 1100-1200.

I say the condition is intermittent, because it seems to occur when the weather gets wet. The first time it showed up, it would go away after warm up, but today it has been more persistent. I have only had the truck for a couple of months now, so this is just some of the fun process of finding what all is wrong with the new acquisition.

Another possible noteworthy thing. there is a very subtle hesitation, kind of a, one, two, stumble that is very subtle. I seem to be the only one that feels it, but it is there.

I figure, most of this is Vacuum related. The engine compartment is very clean and the few lines I have fondled, were soft/flexible. I will try to allocate the time to do some poking around, next couple of days are gonna be wet.

Peace Y'all, Wolf

[wingnut510]

New wrinkle in the problem with the idle. It appears to be associated with the blower motor for the heater/defrost. The A/C compressor has been disabled, and the dash A/C selector switch is off, so it is not the normal bump in idle associated with A/C operation.

So far, no input from the forum. I hope some sleuthing around in the FSM, will end in useful clues.

Hmmm? It just occurred to me, that I think the mode selector is in Defrost, so there may be an interlink between the compressor circuit that is not select-able. Still does not explain the surging, gonna have to wait till later to test this theory.

Thoughts?

Peace, Wolf

[Rainwood]

I have a 03 w/ a 3.3L. I am not so familiar with the 4 banger but, if it has the same grounding problems as mine you may want to look into Nissan's recalls and see if there is a Technical Bulletin written about that for your engine. It did clear up some issues of running lean which could cause idle problems for you. After that, look at adjusting your throttle body and linkage. Good luck.