tke148

Idle issue:

First off I did a search and couldn't find anything associated to my exact issue. Maybe someone can help?

I have a '99 SE 5 sp. w/ 165k.

When first starting the car cold the rpms rev high to 2k and higher. When they get to about 2200 the car then drops to 1500 and slowly up to 2200. Once the car warms to normal temp it seems to run close to normal.

I have removed and cleaned the following, replacing the gaskets in the process:
IACV
TPS
Throttle body
MAF

The TPS was tested and adjusted by the dealer when i had another issue fixed (leaking intake manifold gasket replaced). So, I don't think it's the TPS.

Also, I said 'close to normal' when driving. Every time I push in the clutch to slow to a stop the rpms will sit at about 1500 then fall to about 600-800 rpms. And while driving, the accelerator is touchy when starting to depress it making the car jumpy.

This is starting to drive me nuts. Please Help!!!

Thanks.

aackshun

iTrader: (3)

I have the same "problem" i guess... This only happens to me when the car is cold, when the temp gauge gets a little bit below the middle it runs just fine.... IMO I think that's just "close loop mode" (or it may be "open", I forget which term it is exactly at the moment), the car trying to warm up.

::EDIT::
Check for vacuum leaks too.

mahanddeem

It's normal (althought alil bit 2000 or 2500 is kinda high..) ...
When the car is cold (like when you turn it on at morning) the idle jumps for a while in the 1500~ area...then slowly drops to about 700-800 when it's fully warmed up...
My car seemed to idle higher (especially at morning..i.e. cold) after I cleaned the TB and IACV....So I re-adjusted the idle using the black plastic screw on top of the IACV..Search about adjusting the idle using that way,you'll find many threads about that issue........
and my advice is to wait to idle for 2-3 min at morning before you take off with your car...taking in account the temp in these days are coming colder.........

tke148

thanks for the info.
I've owned the car since new and know the issue I'm having is not normal.
I'll try adjusting the screw but since the idle eventually settles to the correct rpms I'm not sure how much I can adjust it.

tke148

I adjusted the idle screw but that didn't have any affect.

My issues deals more with the 'control' during warm up. What controls the engine rpms when the car is warming up? Is it the tps, IACV, EGR? Once I figure that out I will be able to narrow down a fix.

Thanks!!

Tom

iflossdaily

I'm having the same issue. Mine is completely normal when warm, but when cold it will rev continuously from 1500-2100, over and over. It's very unsual. I cleaned the TB and used Seafoam in the intake. I understand it takes a while for the ECU to work itself out, but it's been about 3 weeks, and I'd think it would be normal by now. Any luck yet? I'd also like a solution...

mahanddeem

you also can check your TB cable tension,can be alittle bit tense more than it should be

smai555

there is a cold idle valve on the bottom of throttle body when the coolent is cool it open up the throttle body to let more air in for a higher RPM and the coolent warms up it closes the throttle body and lets the IACV take over

so that part maybe opening too much or needs adjustment

RAZ76

iTrader: (8)

It's normal guys.

tke148

How can the cold idle value be adjusted? This very well could be the issue. I know I had to disconnect two hoses when I took off the TB and lost some of the coolant in those lines. I figured the system would replenish the fluid after reattaching the hoses, could there be a air void in the coolant system that is causing the idle issues?

I have a Haynes manual and will see if it's mentioned in there tonight after I get home. But if someone can answer that question before then, that would be apppreciated.

Thanks.

aackshun

iTrader: (3)

I doubt this will help much but the problem has completely went away for me...

When I posted earlier, I had a broken MAF -> Cone filter adapter, which allowed air to seap in, also wrecked havoc on my car making it run really lean or really rich at times... Well this week I got a BOMZ SRI from eBay, as soon as I installed that part, after awhile I noticed that my idle had returned to normal and that the idle wouldn't jump around as much, even when cold (along with a happier max).

So my point is to closely examine your intake for any cracks, or sources of a vacuum leak. Which is what I said do earlier lol...

njmaxseltd

iTrader: (19)

There is a linkage from the cold idle plunger with an adjustment screw. The cold idle plunger and linkage is down under the left side of the TB. There are also scribe marks on the linkage, most likely no longer visable because of corrosion. Adjust the linkage as necessary to obtain your desired cold start idle speed. Mine is set to approx. 1500 RPM.

To set a proper idle speed and help eliminate the hang.
Get the car completely up to operating temp. Drive it!
With the engine off, disconnect the TPS. Make sure all accessories are off.
Start the engine and set the throttle body set screw to obtain ~550 RPM's in park or neutral.
Turn off the engine and reconnect the TPS.
Restart the engine and make sure idle speed is within spec. ~650. If it's not, adjust the IACV to obtain the correct idle speed.

tke148

Is it possible to get a picture of the exact adjustment screw for the cold idle plunger. I looked at the TB last night but couldn't figure which one to adjust.

Thanks

jholley

iTrader: (13)

The cold idle plunger is part #16391U on this site:

http://www.courtesyparts.com/maxima-...1800_1801.html

It's on the lower left side of the throttle body. After adjsting this screw my cold start RPMs dropped from 2000rpm down to 1400rpm.