spiromax

Some people say, "If it ain't broke, don't fix it." My motto is, "If it ain't broke, fix it until it is."

I decided to take my Maxima, which was running just fine by the way, and clean her air filter (K&N) and her throttle body. Cleaning the filter was easy enough. I used K&N filter cleaner and filter oil and followed all the instructions properly. I've done this twice before, so I was pretty comfortable with the process. It was my first time cleaning the throttle body, though. Once I got the TB off, I made sure to handle it carefully with clean lint-free cloths. I used spray-on carb and throttle body cleaner to get all of the nasty dirt off of it, and I made sure to be thorough on and around the throttle plate. After I was done cleaning the TB, I let it sit for about fifteen minutes before I reinstalled it, just to make sure all of the cleaner had evaporated.

*Later that night*

My filter was clean and rinsed, and it had finally dried out enough for me to oil it and reinstall it. I oiled it and waited for the oil to set in, then I hit the few white spots on the filter with a touch more filter oil. While I was waiting for the last bit of oil to set in, I reinstalled my TB and plugged it in. Then I reinstalled my Berk pipe and MAF. All I had left to install was my filter, so I took another clean cloth and dabbed the pleats of the filter to make sure there wasn't a bunch of excess oil on it. Then I popped it on and tightened all the hose clamps. ALL DONE!

Then I tried to start the car.

START > ROUGH IDLE > DIE

Then I try to start it again.

START > ROUGH IDLE > ROUGHER IDLE > WON'T EXCEED 2K RPMS

Damnit. The check engine light is on. MAF trouble. Friggin MAF trouble. I think for a moment, then I realize that my MAF isn't blown at all. I merely forgot to plug it in. I plug in my MAF, take a good look around the engine bay to make sure everything else is plugged in and/or screwed tight.

Then I try to start it again.

START > IDLE SLIGHTLY ROUGH AND A BIT HIGH > REVS UP FINE

So the car is running now, and it will go over 2K RPM, so I assume that the MAF isn't blown. Of course, my check engine light is still on. I go check the trusty Org for the ECU/CEL reset procedure, and I print it out so I can look at it in the car while I reset everything. On my second try, I successfully perform the CEL reset.

Since the CEL is gone and the ECU is totally reset, I decide to do the accelerator pedal release position learning procedure and the throttle valve closed position learning procedure. Then I drive the car around, and it still seems to be idling a bit too high. I decide to do the idle air volume learning procedure, which is very similar to the ECU/CEL reset procedure. After doing that, my idle went down to a more normal level, and I figured everything was fine. I knew it would take a while for my car to adjust to my driving style, but I was willing to put up with that to get rid of the ugly orange light on my dash.

The next day, my CEL came back on. My idle still seemed fine, and my car isn't exhibiting the "limp mode" characteristics that would indicate a bad MAF sensor. I reset the CEL again.

Tonight, as I pulled my car up to the auto parts store so I could buy some new high beam bulbs, my CEL came back on. I reset it again, and it went away. Then I did the idle air volume learning procedure again. After doing the idle air volume learning procedure, my CEL came back on. I performed the ECU/CEL reset AGAIN, and I'm hoping that the CEL will stay off this time.

I have a feeling that it's going to go off again. If it does, I'm going to go get the guys at Autozone to read the code for me. I just hope I didn't break anything. By resetting my ECU back to its stock settings, I don't know if I confused it. After all, I have a BERK intake, so I might have a higher volume of air flowing over the MAF sensor than I would if I still had my stock intake. If my car's ECU is expecting a stock intake, would subjecting it to the increased airflow of the Berk immediately after resetting the ECU cause the computer to get confused? The ECU decides how much fuel to deliver based on an indirect calculation of air flow based on the voltage required to keep the MAF sensor at a constant temperature, so that almost sort of makes me think that the high idle was a result of my Berk. The car was detecting high air flow over the MAF, so it dumped in more fuel.

This is just my theory. It does not necessarily explain the CEL. I need help from a Maxima guru of greater intelligence than I.

dkotanto

iTrader: (1)

Spiromax,

Thanks for the warning. I was going to clean my TB and K&N (stock intake) soon but after reading your post, I'll leave it alone. Keep us posted with the outcome.

Jim K.

00i30T

I thought that once you reset the check engine light, that it took a while for the computer to reset itself, something like 200 miles? Is that not right?

Chucky.

rule da road

Is this a new MAF? I've had the same problem after installing a new MAF. Put my intake back on actually tighter than before. AZone gave me code p1130, something about too much air getting to egine with intake. Hopefully a reprogram will fix

spiromax

*UPDATE AND SHORT RECAP OF WHAT HAPPENED*

I'm getting the code P0507 (Idle Speed Control System RPM Higher Than Expected). I recently took off my Berk intake so I could clean my K&N filter and my throttle body. After I cleaned everything and put everything back together, I accidentally started the car without the MAF sensor hooked up. Of course, my car ran very roughly, and it wouldn't rev over 2500 RPM.

After I hooked the MAF sensor back up, the car seemed to rev like normal, but my idle was rough, and my SES light was on. I did the ECU reset procedure, and that made the SES light go away, but my idle was a bit high. After driving it around the block, I decided to do the accelerator pedal release position learning procedure, the throttle valve close position learning procedure, and the idle air volume learning procedure. After all of that, my idle went down to normal, and my car stopped feeling "wrong" when I drove it. It actually felt and sounded better than it ever has before.

Unfortunately, the more I drove, the higher my idle seemed to creep. The light has come back on twice, and I have reset it both times. I'm going to check to make sure I hooked everything up properly, and then I'm going to perform all of the reset procedures again. If that doesn't fix it and the light comes back on, I'm just going to let the light stay on for a couple of weeks to see if going through a complete drive cycle will give the ECU time to correct the problem by itself.

spiromax

Your problem code is P1130 (Swirl Control Valve Control Solenoid Valve). Hell if I know what that's supposed to mean.

My problem code is P0507 (Idle Speed Control System RPM Higher Than Expected). My working theory is that the unusually high idle is being caused indirectly by my Berk intake.

According to Sarah Forst:

"Mass Air Flow (MAF) systems use a sensor mounted in front of the throttle body that directly measures the airflow into the engine. Nissans use a hot wire MAF sensor. As air flows past a heated wire, a circuit measures the electrical current. The engine computer sends voltage to the wire to maintain a fixed temperature. Air moving past the wire cools it and more voltage is needed to keep the wire the fixed temperature. This is proportional to the mass of air flowing across the wire. Since MAF systems measure direct airflow, they can adapt easier to engine changes and modifications as well as being more responsive and accurate."

The throttle is really the "air pedal" instead of the "gas pedal." The ECU determines how much fuel to deliver based on how much air is entering the engine. Since the amount of air flowing into the engine is determined by an indirect calculation based on the voltage required to keep the hot wire MAF sensor at a constant temperature, it follows that any change in intake air temperature or intake air volume would effect the ECU's decision on how much fuel to deliver to the engine.

My Berk intake flows more freely than the stock intake, so more air would be flowing over my MAF sensor with the Berk than with the stock intake. Because of the difference in airflow between the Berk and stock intakes, it's possible that when I reset the ECU to its baseline settings, the extra airflow reading from the MAF sensor caused an increased amount of fuel to be sent to the engine, resulting in a higher idle speed. The problem is that the throttle position sensor would still see that the accelerator pedal was fully released. The ECU might be confused, since the throttle position sensor says that the throttle is released while the MAF sensor is reporting a volume of airflow that would indicate partial throttle application.

Performing the idle air volume learning procedure fixed my idle once, but then the idle speed slowly crept back up high enough to make my SES light go off. Like I said before, I'm going to try performing the procedure again, but if the SES light comes back, I'm just going to go through a full drive cycle to see if the ECU will learn the new intake and correct itself.

HNDA ETR

iTrader: (10)

any updates?

spiromax

I'm really not sure anymore. My MAF was fine, according to the dealership who bumped my timing up to 17 degrees. They said the problem was with my throttle body. I guess they figured I must have broken it when I cleaned it. I wasn't aware that the TB was too fragile to be cleaned.

The whole dealership experience was very shady. They ended up fixing whatever the problem was with my idle, but I'm not so sure it was my TB.

Epacy

iTrader: (6)

Other people have cleaned their TB and haven't had any problems or broke it. It doesn't seem like it is too delicate.

Bluesbrekr

iTrader: (4)

I wouldn't reset the ECU so fast. When a problem is detected the SES light will come on. If that problem is not detected on the next few starts the light will go off. By resetting the ECU that often, you may not have given the light a chance to go out by itself. In other words, if it's an isolated problem it may 'fix' itself.

screamindman

THis is sort of related. When I installed my Frankencar intake with the Stillen K&N filter set up, my cars idles slightly lower than before. It looks like it idles at 750rpm roughly. I've had my MAF changed twice due to malfunction, so I'm not even sure what MAF they replaced it with. So far so good (about 11K miles), but it's like a black cloud looming over my head, not knowing when I'll see the dreaded check engine light come on again for the same reason.

Epacy

iTrader: (6)

I cleaned my TB yesterday and there was alot of that black nasty goo intside the TB. I really would like to take the whole thing off and clean it. But I opened the valve and cleaned some inside there. I did start the car and I already a CEL for EVAP but I reset the ECU then anyway in case something else popped up from the cleaning. When I took my car out last night, I noticed the idle was all over the place. It reved up really big when I started it. I did have an issue where it would cut out sometimes after I started it, but I found I forgot to tighten the clamp that hold the rubber hose onto the actual TB from a week before. When I would brake the idle kept jumping up all throughout the braking process until I stopped. I went out this morning and most of that is gone. The RPM's only jump right before I come to a complete stop. It has definately got better and no CEL light yet. It seems it is learning the new air flow.

paralyse

I've heard stories that cleaning the throttle body on the VQ35's w/DBW (electronic throttle) that you can damage the throttle plate, shaft, or motor if you try to force it open to clean the throttle body. If the plate or shaft got bent or damaged it could screw up the idle. Given the extremely limited benefits of throttle body "Cleaning" i can't encourage anyone to try it on their 2k2+. If you want to see a real gain take your upper plenum off, separate it from the throttle body, clean both pieces separately and re-assemble, then run some sort of combustion chamber cleaner (seafoam, etc) to break up the carbon.

Perform the ECU reset/idle air volume and throttle position learns.

max007

I have the exact same problem after cleaning the TB. Has anyone attempted to take the TB sensor apart to look at the possible bent shaft/plate/motor? I never forced the TB plate open at any time, must be very sensitive and I would never recommend anyone doing this.

jjj

ecu or solenoid

Audtatious

Wow. Thanks for the info. I'm sure that solved their problems...

Epacy

iTrader: (6)

He is just post whorin. He has been doing it all the threads.

Audtatious

Yeah, I've noticed. I thought that was a banning offense

Epacy

iTrader: (6)

He should be banned.

Built2prfctn

def should be

Epacy

iTrader: (6)

Well I popped a code, different from the ones I was getting. It was related to the Throttle Body cleaning. P0113. The PCM has determined that the input from the intake air temperature sensore is higher than expected for the current engine operating conditions.
Well, I performed the Accelerator Pedal Release Position Learning Procedure for 2K2+, Throttle Valve Closed Position Learning Procedure for 2K2+ and Idle Air Volume Learning Procedure(Throttle Position Learning Procedure) for 2K2+. After this I reset the ECU and the code was gone, but before it took a little driving around to get the code to come on, so we will see. The idle speed is better though.