Abbreviations and what they are... help

[Crunkrich]

I've read so much about clearing up my rough idle my head has started to hurt with all the different abbreviations, what they mean, and where they are located. Could you say what these stand for, what they do, and where they are located, I've done as much as I know but correct me if wrong. Thanks a bunch

AIV - Air Idle Valve, located behind the stock airbox connected by a short vacuum hose, controls the fuel injection to air ratio (i think this is right)

AAI - ?, located on the passenger side side of the engine below the intake manifold, ?

AICV - Air Idle Control Valve, ?, ?

MAFS - Mass Air Flow Sensor, just past stock airbox, measures amount of air taken in

Are some of these the same and that's why I'm getting lost when reading about them and the material is all similar? If there are any other valves/sensors related to intake / fuel injection a heads-up about those would be awesome, thanks again
Modified by thenameismatt at 7:28 PM 4/16/2006

[rsmithdrift]

AIV = Air Injection Valve. It's connected to the exhaust manifold and goes to a black box that connects to the intake air box.

It injects air into the exhaust when there is a vacumm on the system to help the cat warm up. If it malfunctions it'll inject exhaust gas intot he intake and make your car run stupid.

MAF is the most important device under your hood for controlling your Air/fuel ratio. Make sure it works properly or you'll be sorry.

CTS = Coolant Temperature Sensor. It's another very important device for controlling air/fuel ratio. It's the red bosch type connector on your upper radiator hose where it goes into the motor. If it's bad your car may not start and you'll loose 10hp.

O2 sensor another very important device for controlling air/fuel ratio. They need replaced every 90k miles and will make your car fail emissions, loose power and get god aweful gas mileage.

IACV = Idle Air Control Valve, this adjusts your idle.....nothing more.

[Crunkrich]

I figure I'll just describe everything that happened from day one I started having the idle problems... here goes... I know its long please bear with me

-First I bought a short ram intake from ebay (yeah bad choice i know lol) and when I went to install it, the pipe didnt fit nicely how the stock one fit.-When it ran down to meet the throttle body it was off by about 1" to the left, so I had to put the rubber sleeve on it and push it down to meet the throttle body as close I could get it, when sealed off with the sleeve it was still about 1/2" to the left.-All three hoses connected to the intake near the throttle body were connected properly and sealed off.-the MAF was connected but the metal adaptor plate for the filter didnt line up perfectly so I had to make it fit as close as I could, ended up so that if I looked directly in through the adaptor plate it didnt line up with the pipe; it was about 1/2" off. (my guess here is the air was not being fed with as great a volume over the sensor wires for the maf, so the maf was getting a low air signal).-my intake kit didnt have a connection for the AIV hose, so i just left it open in the engine bay w/o a breather on it... dumb i know now

-after about 2-3 days my idle started acting up, or down rather lol. It would idle around 200 and come close to stalling out. After constantly driving heel-toe for about 2 weeks, it cleared up and ran fine for a month or so. Then it started doing it again randomly, but if I ran it harder than usual it ALWAYS stalled out when I let off the throttle. After two months of this, I got some fuel injector cleaner and ran that through and it cleared up for a week or so. Then it started idling anywhere from 1500-200 all the time anytime. I finally just reconnected everything stock thinking that reconnecting the AIV and properly connecting the MAF would fix the problem.... nope.

Any ideas what could be wrong? First thing I'm planning on doing it cleaning the AIV as soon as I get home. I know that was really long thanks if ya read it and any help would be great.

[180fan]

The AIV can do some weird stuff but it won't cause a near stall out. I suspect either a mafs or vac issue.

[rsmithdrift]

Take a look into your MAF sensor......if it's dirty, then spray it with carb cleaner.

Check ALL VAC HOSES FOR LEAKS.

What I would do first is to jiggle every elect. connection under the hood next time it runs stupid. I'd even take it farther and diconnect then reconnect them while it's running.

If doing this solves your problem temporarily......THEN CONGRADULATIONS!!!!! YOU MUST OWN A NISSAN!!!! LMAO Seriously it's a very common problem with nissans over 5 years old. I'd put dielect. gel in every important connection just for good measure.

[Crunkrich]

thanks for all the help

ill be able to check all this stuff as soon as i get home (family vaca on spring break lol) could you elaborate a little bit more on the dielect gel? thanks

[rsmithdrift]

thanks for all the help

ill be able to check all this stuff as soon as i get home (family vaca on spring break lol) could you elaborate a little bit more on the dielect gel? thanks

You can get a tube of it from any autoparts store, and even walmart, kmart, taget, etc.k

Anyways, you disconnect your elect connections under the hood and put some of the gel in there and it greatly improves the elect. connection and that can solve all sorts of problems with your car you probably didn't even know you had.