Ok I have searched and all that but can't find anyone with my particular problem.
First of all the engine only has 79k on it (1993 S13). When I got the car I had new intake, cap/rotor, plugs, plug wires installed. I also had them do the B&G cleaner or something like that.
I changed the 02 sensor about two weeks ago. (big thanks to those on this board that walked me through it).
It seems everything is working OK and I get 25-26 mpg (city driving).... I will be getting the drive belts changed tomorrow.
Ok so on to the problem.. you know when you idle without the A/C on and then when you turn it on, you hear that click coming from the engine bay and then your idle goes up since its using more power?
I notice that when I am driving then braking and coming to a stop, the idle drops to the 500rpm line and shakes a little. Then it moves up a little bit... then you hear the click, and it goes back up to normal levels. The A/C is on the whole time.... if I drive without the A/C same thing happens..... then if I sit there long enough (stop light) it will drop 100-200rpm for no reason, then you hear the click again and it goes back up. On long stop lights this process may occur a few times during the duration of the idle.... havent tested if the click happens when A/C is off but it happens when it is on... when A/C is off, the same slow bob effect still occurs.
ANOTHER idle problem (searched)
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O0ooAJoo0O
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SkylineDriven
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Ok I will consider that... any other suggestions out there? What would explain that "click" sound right before the idle bumps back up to normal levels. The click I am guessing is NORMAL when you turn the AC on for the first time but I dont think it is normal when you are sitting idle and watch it drop, then click and go back up, then drop a minute later, and click back up again.
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O0ooAJoo0O
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the click is probably a relay. look in the panel under the passenger side front wheel well. its right under the glove box. i think you have to take off the plastic cover. the ECU clicks sometimes, get someone to listen and then you manually make the car make the "click" most likely its the AC relay, but i doubt that is related to the idle problems.
it sounds like there is a relay in the ECU that cuts out the ac momentarily, when braking. ive heard of something similar to this before. i know mine used to drop rpms, but my ac is broken, so its always off.
also, you might want to check and see if the AC clutch is working correctly, look for a belt spinning, not sure which one, i havent done any AC work.
that rpms bobbing effect could also be temperature sensitive? maybe, have your temp sensor checked, or check if its even plugged in, mine shakes loose sometimes.
lastly, i would check all of your vacuum lines, even the little skinny ones. theres some on the intake box, theres some under the AIV, theres some on the throttle body, CHECK them all. idle problems are almost always a leaky/loose/unattached vacuum line.
hope that helps, keep me posted
it sounds like there is a relay in the ECU that cuts out the ac momentarily, when braking. ive heard of something similar to this before. i know mine used to drop rpms, but my ac is broken, so its always off.
also, you might want to check and see if the AC clutch is working correctly, look for a belt spinning, not sure which one, i havent done any AC work.
that rpms bobbing effect could also be temperature sensitive? maybe, have your temp sensor checked, or check if its even plugged in, mine shakes loose sometimes.
lastly, i would check all of your vacuum lines, even the little skinny ones. theres some on the intake box, theres some under the AIV, theres some on the throttle body, CHECK them all. idle problems are almost always a leaky/loose/unattached vacuum line.
hope that helps, keep me posted
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SkylineDriven
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Slippery S14
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The clicking when the ac shuts on and off is more or less normal. Like others have said, its probably just a relay that is not in perfect shape but *I* wouldnt worry about it. Does your idle fluctuate without the ac on and the brakes pressed, ie, when you are coming to a stop with the ac off does the idle fluctuate? I really think you are dealing more with an idle problem when the engine is under strain than with an ac problem.
I think someone else mentioned the aiv and hose checks(from what ive heard, the aiv *typically* takes care of these idle issues).
-Slip
I think someone else mentioned the aiv and hose checks(from what ive heard, the aiv *typically* takes care of these idle issues).
-Slip
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SkylineDriven
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Ok.. turns out that it was only when AC is on as I previously stated.... well I took the car in today to get the belts changed.. and I also told my tech about the idle problem... he told me that its normally recommended that the idle be adjusted everytime the engine is tuned up and he says they have a comptuer thing that puts it under stress and use it to adjust the idle control... well my nonAC idle is fine... and well actually for some reason after the belt changed.... my AC idle is a little better... maybe he also adjusted it for me? dunno.