Idle Bad when cold, Improves with warmup..
#1
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Idle Bad when cold, Improves with warmup..
When i first start my car after sitting the idle seems to be rough. Like its misfiring every other second or so. After the car warms up or gets warmer the idle gets better. When it was warmer out the idle seemed to be good just about always too. So i was thinking something metal is the problem. When its cold the metal part is contracted and making less contact, and once it gets warm it expands creating a better connection? just a theory. Maybe its my wires or something simple?
#2
Somewhere it is said for older cars should not be "quick started". Which means that the vehicle should not be in motion (Our for some people, in high revs or acceleration) without the Maxima reaching operating temperature. For me, that means just as long as the temp gauge needle is not in the lowest position. One time I stalled my car by quickstarting. I could put it in D without warming it up.
Anyone else have any ideas?
Anyone else have any ideas?
#4
Don't want to derail, but I have the reverse problem. My 93 GXE idles like a dream when it's cold started. When the engine warms up, however, it idles horrible and I think it runs rich because I can smell gas in the exhaust. I swapped out spark plugs, distributer cap and rotor, PCV valve and CTS. Does anybody know what could be up ?
#5
In both cases try ECT sensor and IACV
92gxe/cg2 - all your vacuum hoses in good condition and properly connected?
Darkwing48 - I too don't like to use anything near full power (even half is too much imo) on a cold engine and especially old and cold auto box, but there is no real reason not to start moving the vehicle soon as its started - it was made to be able to handle that situation
92gxe/cg2 - all your vacuum hoses in good condition and properly connected?
Darkwing48 - I too don't like to use anything near full power (even half is too much imo) on a cold engine and especially old and cold auto box, but there is no real reason not to start moving the vehicle soon as its started - it was made to be able to handle that situation
#6
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In both cases try ECT sensor and IACV
92gxe/cg2 - all your vacuum hoses in good condition and properly connected?
Darkwing48 - I too don't like to use anything near full power (even half is too much imo) on a cold engine and especially old and cold auto box, but there is no real reason not to start moving the vehicle soon as its started - it was made to be able to handle that situation
92gxe/cg2 - all your vacuum hoses in good condition and properly connected?
Darkwing48 - I too don't like to use anything near full power (even half is too much imo) on a cold engine and especially old and cold auto box, but there is no real reason not to start moving the vehicle soon as its started - it was made to be able to handle that situation
#7
Yes my vacuum hoses are fine, and all that. Ive heard about the ECT (engine coolant temp??) sensor before and would liek to replace mine to see what happens. Where is this sensor at, what does it do that could interfere with the idle and how do i chagne it out? I believe i heard it was a simple sensor u just pull out but dont know for sure. i also highly doubt theres aynthing wrong with my IACV just to put that out there..
Last edited by Maxteca; 11-16-2007 at 10:03 PM.
#11
#16
Just be sure to buy new gaskets before you take it apart to clean/replace..
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#22
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john lets get some examples? Like when my plugs rotor and cap were bad, even tho i said they werent, and were they now? no..... lol but back to the IACV
ive read some symptoms of a bad iacv and mine doesnt have said symptoms. Also my idle is always a constant RPM, never fluctuates, slowly lowers itself when going from cold to hot after driven etc....
Im sure its possible to have a faulty IACV even if the idle speed is perfect and never fluctuates but im just doubting that. How would an IACV lead to a misfire too? i probably should clean it because even when theres no misfire and its idling fine u can feel a vibration thru the cabin more like a pulsing.
ive read some symptoms of a bad iacv and mine doesnt have said symptoms. Also my idle is always a constant RPM, never fluctuates, slowly lowers itself when going from cold to hot after driven etc....
Im sure its possible to have a faulty IACV even if the idle speed is perfect and never fluctuates but im just doubting that. How would an IACV lead to a misfire too? i probably should clean it because even when theres no misfire and its idling fine u can feel a vibration thru the cabin more like a pulsing.
#23
ECT determines mixture quality presented to the cylinder based on temp - the colder the richer in general. If the ECT tells the ECU lies, a lean mixture can be caused, and non-reliable ignition is the result.
If all else seems to be in good nik and working I guess the most basic of causes of this may simply be engine condition.................
Remove and block the crankcase breather hose from the rear valve cover (leave the nipple on the valve cover open) - is there an improvement/change in the symptoms described in your first post?
What are the actual individual WOT cylinder pressures when doing a hot compression test?
If all else seems to be in good nik and working I guess the most basic of causes of this may simply be engine condition.................
Remove and block the crankcase breather hose from the rear valve cover (leave the nipple on the valve cover open) - is there an improvement/change in the symptoms described in your first post?
What are the actual individual WOT cylinder pressures when doing a hot compression test?
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