strange idle at stop in drive or rev

86fazer · Post by **86fazer** » Thu Apr 22, 2010 2:48 pm

hey all hows it going on a 2000 model with auto trans 80k miles there's a strange low idle that happens, but if I tap the throttle it comepletely goes away untill the next stop. Back at 50k I read on the other neons.org the fix was simple, decarbonize the throttle body, gap the plugs and put a small hole in the butterfly instead of adjusting the set screw to bring up the idle some and alleviate @ stop vibrations with out the a/c on. ( never does it with the a/c on)

seems like it would be a vac leak but vac leaks go back to sparatic idle even if you tap the trhottle.

soo thought I'd ask the big 2ng family if anyone had this happen yet and what their fix was.

Thx Anthony

Paul56 · Post by **Paul56** » Thu Apr 22, 2010 3:35 pm

If by strange idle you mean a rougher idle... yes I have that.

If the AC is on

-or-

I shift into neutral

-or-

I move the wheel enough to engage the power steering

...the idle smooths out.

I just live with it.

NEON PARABOLA · Post by **NEON PARABOLA** » Tue Apr 27, 2010 1:08 pm

this is exactly my issue. I found it interesting that simply screwing with the steering wheel fixes the choppy idle. What exactly is the diagnosis? is this a sign that the engine is on the tail end of it's life? something geting ready to fail? I would love to fix this....

esfan · Post by **esfan** » Tue Apr 27, 2010 1:34 pm

viewtopic.php?t=50153

Refer to the above link.
Not need to worry about a lot. IAC dirty.

sidepipe87 · Post by **sidepipe87** » Tue Apr 27, 2010 1:55 pm

^He's on to something.

I have the same issue on my '00 too. It idles very rough and at stops or in traffic it feels like it's going to stall out if I don't throw it in neutral. When I get a chance I'm going to clean the IAC. Should fix the problem.

esfan · Post by **esfan** » Tue Apr 27, 2010 2:54 pm

Actually I don't think it will stall, just the rpm is around 500-600 which is considered low and causing horrible vibration. If you are with the engine mount inserts, then the vibration could be even worse.

gilly02le · Post by **gilly02le** » Tue Apr 27, 2010 4:42 pm

It's not the IAC. It's a screwup in the programming for the computer. It's called idle undershoot, and to fix it, like you said, drill a 1/8" hole in your throttle plate. Voila, problem solved.

86fazer · Post by **86fazer** » Thu Apr 29, 2010 12:49 pm

gilly02le wrote:It's not the IAC. It's a screwup in the programming for the computer. It's called idle undershoot, and to fix it, like you said, drill a 1/8" hole in your throttle plate. Voila, problem solved.

did that 5 years ago and now it's back, cleaned everything on the intake side... something somewhere is carboned up and I have no sparkplug tubes leaking oil or bad coils, wires, plugs etc. so far checking all the vaccum areas to see if there is a leak of some sort but since it only does this during a stop, not with a/c on or with the engine cold, only after it's in op temp range.... really weird and annoying even will throw the low oil pressure light on at times ( and yes oil lev is correct)

odd none the less but soon as I figure it or another posts we will be good to go again

cgneon · Post by **cgneon** » Thu Apr 29, 2010 4:23 pm

try gapping your plugs to 32.. mine hasnt done it since..