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Won't idle cold, runs fine at operating temp
2002 Nissan Frontier, 137000 mi. I-4, Auto
I was having rough idle when cold, and wouldn't keep running without pumping throttle like crazy and then most times had to restart 3 or 4 times. Once engine reached operating temp, it did ok. Light was on and Code was 420. so I replaced MAF, O2, and upstream sensor - light stayed on. Then found leaking valve cover gasket and fouled plug in #4. Code was 420 and 306. After new spark plugs, wires, dist cap and rotor, valve cover gasket, runs smooth and fine AND all codes reset themselves, which the mechanic was puzzled about and could not explain. BUT I still have rough idle on cold start and engine dies. AND if I bring it up to 3000 rpm and hold it, it stays there for 3-5 seconds and falls off and dies. And again, drive it a few blocks, warm it up, and it does fine, smooths out, and starts fine for rest of the day. Sitting overnight and idle problem returns. Also I started it today in 81 degree weather after sitting since yesterday and same problem. What do you say? Remember, all codes are now cleared and no dash light. Last edited by BgDnTX; 10-02-2016 at 05:13 PM. |
#2
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Still looking for some suggestions - would really like some help on this. Thanks
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#3
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You might have a bad distributor.
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#4
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It sounds like a problem with the IACV-AAC Valve, which is used by the ECM to control cold start fast idle and help maintain idle under loads. Sometimes the valves get dirty and stick and sometimes they just stop working and need to be replaced. A factory service manual can instruct you on how to check the valve and its circuit.
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#5
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Thanks. New distributor writes plugs, and pulled the air box off seem to help. When air box is installed problem returns, goes away when removed. Guess I'll run a straight duct and leave it off.
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cold, fine, idle, operating, runs, temp |
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