2001 sentra se idle question

After my car has warmed up, and idles around 750 rpm, and I come to a full stop, the idle is smooth for 10 seconds. Then the engine stumbles, the idle dips down to 250 rpm for 2 seconds, almost stalls, then the idle goes back up to 750 rpm. I have new spark plugs, spark plug cables, clean air filter, ( there is no fuel filter, except for the one inside the tank(brillant, NOT!)).

5 speed manual, and my mechanic (at a Nissan dealership) claims to have tested the fuel pressure, and sez it's ok. He wanted to change some valve for $369, but said he wasn't sure if that would fix the problem, so I declined. Any ideas?

-Don

Reply to
Don
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Sounds like it could the the Idle Air Control Valve. Looks like this:

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It should be located on top of or on the side of the Throttle Body. Should be a pretty easy swap if you want to do it yourself. It will run you $134 from Napa. Sure beats the $370 at the stealership.

Reply to
AA

Thanks for advice. I can't find anything similar to the pic on my car, though. There doesn't seem to be a Chilton's or Haynes book out yet for my car. If I do locate the IAC valve, could it be cleaned using carb cleaner, assuming the solenoid works? I miss the simplicity of my '66 beetle...unlike this car. There's a weird black plastic hook thingy sticking out of the throttle body/air intake area, no wires, no vac lines, no cables, doesn't go any where, wtf could it do? Infact, it looks like a question mark.

Reply to
Don

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Check out the linked pics. I just went out and took a few of the IAC on my girlfriend's '03 SE-R (2.5l). If the design is similar between engines, it should look something like in the pictures. It is the finned black piece on the back side of the throttle body. Once you find and remove it, you can try to clean it with some carb cleaner, taking care to not "clean" the electrical parts with the carb cleaner. It's pretty corrosive stuff for sensitive electronics. I haven't had much luck in cleaning them out in the past, some have though. My attempts to clean them with carb cleaner ended up with an idle around 4k and its not the most pleasant feeling in the world dropping it into drive at that rpm to get to the parts store for a replacement.

Give it a shot, let us know how you work out. If you really can't find the thing, post some pictures and I can help you locate the unit.

Reply to
AA

Wow, thanks for the effort! I appreciate it. On my 2.0, the IAC seems to be located at the bottom of the throttle body intake tube. Does anyone know if the IAC can be tested by turning on the AC? I've read that a dip of about 100 rpm would mean malfunction of the IAC valve. I'd like to confirm this. Also, if anyone could comment on the 10 seconds smooth idle, 2-3 second rough idle,

10 sec>
Reply to
Don

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