One Possible Irregular Idle Solution

[flipboi13]

POSSIBLE PROBLEM: Exhaust Gas Recirculation (EGR) Temperature Sensor Faulty.

SYMPTOMS:
- irregular idle at startup
- irregular low speed idle
- RPMS will drop and feel like stalling when moving
 from stop
- triggered "check engine" light
- EGR valve checks OK, but does not operate on car
- slight loss of power (due to EGR malfunction)

The last owner of my 1995 240SX was probobly not treating it with the right diet, (and the damn used car dealer filled it up with 89 octane 'camel piss' right in front of me!!! &nbsp;After replacing a TON of components, I was left with the EGR system. &nbsp;The EGR valve was working correctly, but not operating on the car. &nbsp;When I took out the EGR Temp Sensor, I found lots of solidified exhaust particles all over it. &nbsp;hell if I'll put that in my car, so I replaced it (fucking $140 from Nissan, but $100 from Courtesy Nissan). &nbsp;Voila, the engine idles like a new car, and I don't have to worry about stalling anymore. &nbsp;Apparently, with the EGR Temp Sensor inoperable, the EGR valve itself was not functioning. &nbsp;I doubt this is a common problem, but its something to look into. &nbsp;Peace <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/biggrin.gif" border="0" valign="absmiddle" alt=':D'>

[Potatoskins02]

I'll have to try this...

[Russki]

I have an idling problem and have tried EVERYTHING to fix it, except for the EGR because I didn't know such a thing even existed. &nbsp;Turns out the hose going up to the sensor was torn, I replaced that and nothing has changed which leads me to one conclusion, the sensor itself is bad. &nbsp;Since i've never even knew about this thing, is there something I should test or look for in the old one before I spend the money for a new one? &nbsp;There seems to be remains of some kind of a foam in the middle of it, half of it is missing, is that important? <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/confused.gif" border="0" valign="absmiddle" alt='???'> &nbsp; At the parts store it's 120bux, but since i work for infiniti, i think i can get a cheaper one from nissan. &nbsp;Thanks for any replies.

[flipboi13]

You said sensor, but I think you're talking about the EGR valve. &nbsp;It looks like a mini aluminum garbage top and on the bottom there are a few holes (like 4) and there should be a sort of diaprahm there. &nbsp;This is the EGR valve which is designed to open at around 2-3K. &nbsp;Have someone SLOWLY rev the car in neutral and feel if it moves at that speed. &nbsp;But if like you said, it is torn, then you need a new one. &nbsp;The chiltons said to take it off and attach a vacuum pump to it or something... &nbsp;Then you can test it on the bench, but I knew on the car that it wasn't working by sticking my finger there.

BTW: I don't know what it feels like if it works, so be careful that air don't burn you, i don't want that &nbsp;<img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/wow.gif" border="0" valign="absmiddle" alt=':0'>

[Potatoskins02]

where is all this stuff located in the engine bay? ......

[flipboi13]

The EGR valve should be located behind and slightly below the intake manifold (2 silver discs about the diameter of 2.5") One is the EGR valve itself and the other is another component of the EGR system. There should be all sorts of vacuum tubes connecting them all. The EGR Temp Sensor should be located on the intake manifold and you can see it screwed b/t runners 2 & 3. There's also the EGR tube that runs exhaust from the headers to the intake side of the engine. This is an emissions system, but the engine requires this to be functioning correctly, so its worth looking into.

[flipboi13]

* Double Post *

[Russki]

Ok, after talking about it with my mechanically inclined buddies (infiniti techs) I realized i was looking at the other round thing, not the valve. &nbsp;The hose under it was torn and I replaced it but it didn't help any with the idle. &nbsp;I finally found the valve and pushed with my finger under it while the car was idling and it started to idle even worse, so now I know that it works. &nbsp;Back to the drawing board i guess... <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/sad.gif" border="0" valign="absmiddle" alt=':('>

[flipboi13]

Exactly what kind of idle problems are you having? &nbsp;Are they similar to the ones I had or are there others??

[Russki]

it's a totally weird one...
The motor shakes at idle speed, but there is no power loss or bad fuel economy, I get around 26mpg with city/hwy driving. On most days the idle speed is around 800rpm, but once in a while it's at almost 2000rpm and doesn't go down until i drive around for 20 minutes or so. &nbsp;I think what's effecting the speed is the air temperature because all last winter it was at 2k, but when spring came and during the summer it was around 800 rpm, but who knows.
I have tried adjusting the TPS to the right position, but it would only make my rpm stay at 2k and not even go down, so i just set it to the lowest setting so at leas it wouldn't idle that high. &nbsp;I also tried the idle adjust screw, but ended up just screwing it in all the way. &nbsp;I'm afraid there is some major problems with the motor, but i dont' know, i'm up to try almost anything that doesn't cost an arm and a leg since i'm using this as my beater and getting another 240 that's in better shape. &nbsp;I hope i didn't confuse you too much, any help is appreciated, thanks.

[flipboi13]

If there is nothing wrong with the power output besides the high idle, I don't think there is anything wrong with your motor, probobly a sensor is faulty or a bad connection... &nbsp;Hopefully someone has some ideas on this, in the meantime I'll think about what parts you can check....

[Russki]

Any ideas at all? &nbsp;<img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/confused.gif" border="0" valign="absmiddle" alt='???'>

[flipboi13]

Hey, hope you don't me asking you a few q's. &nbsp;Do you have a DOHC? &nbsp;Have you replaced your PCV valve? &nbsp;Checked ECU trouble codes? &nbsp;Checked compression??

[Russki]

I have a SOHC, have not replaced the PCV valve, I checked the ECU for codes, there was one for an air intake temp sensor, replaced that and didn't check it since, and I did not check the compression. &nbsp;I guess I have just added some jobs to my to do list. &nbsp;I'm gonna check the ECU again and check the PCV valve or replace it. &nbsp;I am not going to do a compression test unless I have a problem that is associated with it.
Thanks for your help.