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I have 2001 nissan altima auto,4 cyl ,85k and the idle is at 1400-1300 rpm during startup, it goes down to 1100-1200 rpm after warmup,,normally it should be in 800-750 rpm,, i cleaned the idle air control valve and adjust the idle screw and also i replaced PVC valve but no changes,,,any suggestion is greatly appreciated,thanks
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Ok,
What’s left….
1 Re-tension springs are weak… not likely
2 Throttle cable not retracting fully … possible
3 Idle cam deformed …possible but not probable. I have seen where some have tweaked the end where it rests on the adjustment screw to achieve the correct idle.
4 Idle adjustment screw changed adjustment … not likely.
5 Idle control valve defective
6 Wear on the throttle body… also possible
My suggestion…
First … Make sure that the idle cam linkage and throttle moves without binding through it full travel.Second … Confirm that the throttle cable moves without binding to both it fully open and closed positions.
Third … By hand, manually push ( with moderate pressure ) the idle cam to its minimal position when the engine is at operating temp.
If the idle drops down to normal while applying pressure to the idler cam, that shows that either, the idle control valve is faulty somehow,
or it could be that the linkage directly attached to it shifted position, or operation wear.At that point you have to decide if you want to replace it or readjust the idle screw to compensate.
I should think operating temp rpm is ~700 – 750 in gear, 800 – 850 in park, so your issue is minimal being your up around 1100.
It can be adjusted out. ( cheating way out )Summary:
Item1- spring unlikely weak
2-trottle cable check out
3- cam not deformed
4- screw was tight
5- are you talking about idle air control valve ?
6 – wear on trottle body,im not sure
Your suggestions 1-3: they were checked no problemI saw this video in youtube about TPS adjustment, does this also apply to 2001 altima? Here is the pic,i dont know how to show the link
Also is it (high idle) because of a blowby engine ? I open the oil cap while engine is running and i put a tissue on top and i think my car is suffering from blowby, note new pcv valve was installed less than a year.thanks
First thing
That article and video (which are very good BTW, I watched many of his repair videos) are for a V6 3.3L.
Not sure if the same procedures will apply to your 4 cylinder.
Actually you need to follow this one More applicable to you. Starting at 4:25 on the videoWith out seeing your exact setup I’m assuming yours is similar.
Forgive me what we have been calling the idle air control valve maybe incorrect…
The issue may be with fast idle coolant solenoid.( which I have on my engine and hoping your has it too.)
As I said it tough when there are no detailed pictures.
But I am trying my best.this is the exactly the same as mine and its selling in ebay,im looking at the “coolant plunger something “where coolant goes in and out ,i dont know if the problem is there somewhere,any comment?
eBay item number: 231589744741Finally some detailed pictures :silly:
Now that I can see what you have …
If I remember correctly, when doing timing you disconnect the TPS (which raises the idle) on my setup
Just for grins and giggles you might try this..
Warm up the engine to operating temp Take note of the rpm.
Switch it off and disconnect the TPS connector
Restart the motor and see if the rpm change.
If I’m correct you may have a faulty TPS
It maybe adjustable or nothttp://easyautodiagnostics.com/nissan/2.4L/how-to-test-the-tp-sensor-1
http://easyautodiagnostics.com/nissan/2.4L/idle-switch-tests
It may also be a wiring or signal issueI’m going to check it out now , brb
btw what do you mean by “If I remember correctly, when doing timing you disconnect the TPS (which raises the idle) on my setup” ? tyThere is a procedure to set the timing EC-650,651,652, Part of the complete Service and repair manual for my truck.
I believe the idle increase when the TPS was disconnected.
It was last year when I check the timing when I replaced the timing belt.all checked out idle linkage resting in adj screw, cam swing to lwest point, I took some pics,
one is 800 rpm in drive or reverse,
1100-1200 rpm in park or neutral with tps connected,
1400-1500 rpm in park or neutral with tps disconnectedYou can test the TPS
Following these instructions:
http://easyautodiagnostics.com/nissan/2.4L/how-to-test-the-tp-sensor-1
And the idle switch with these instructions:
http://easyautodiagnostics.com/nissan/2.4L/idle-switch-tests
So if one or both fail testing well it looks like a replacement is needed.
If they both pass you can try adjusting the TPS using these instructions:
http://easyautodiagnostics.com/nissan/2.4L/idle-switch-tests#2I also found this site about adjustment for a KA24DE engine motor; i guessed its also apply to my vehicle;
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