Frosty

Alright, so my car has hit 75,000 and it was time for a spark plug change, I went with the NGK Laser Iridium. I Changed them out, didn't have to much of a problem. So I drove on them for about an hour or so, I could see some good clean gains all around, but after about 30 mins or so, the service engine light comes on. The only odd thing I ever noticed about the change was a little more smoke than usual out of the exhuast. Any ideas fellas?

sascuderi

May or may not be from the new plugs. I remeber someone else having problems with the Iridium plugs. First step is to get the code pulled at Autozone (for free)

Frosty

for free you say?

Frosty

I was also thinking maybe a ECU reset as well, but thats after I find out what the code is.

aussie983

iTrader: (16)

OK this is what a nissan tech told me off the cuff. He said dont use any other brands of plugs unless they are the original plat nissan ones, or the ngk plats. He said others such as coppers or any other brands will cause problems. Hes seen a lotta cars that get engine probs after switching plugs.
not sure if its true, but thats what he told me.

aussie983

iTrader: (16)

and yes they will lend u the code reader for free, but u gotta pull the code urself and knwo where to plug it in.

Frosty

yea I know where the plug is. under the dash, on the left side right?

limsandy

iTrader: (1)

Never listen to a Nissan tech.

Frosty, did you gap the spark plugs before you install them? Even if they're pre-gapped, you should always check the gap.


~limsandy

Frosty

hmm, no I didn't I didn't think I needed to.

ZIPPIN

iTrader: (32)

that would be me. i changed to iridium at 96000. it misfired like crazy after 2 days. switched back to the old plugs and she drove fine. then came ses. failed coils. changed coils and put back in the iridium. ran fine for a week, and started misfiring. so i bought new OEM plugs. runs fine now. someone suggested the plugs in cars that have high miles, should not be upgraded. in my case it just made the already weak coils worst....

pull the code and get ready to spend some $ on changing the coils...

Rafe

Funny you mention that , i was at my local Nissan dealer Saturday, and a Sentra SE-R spec V was toed in. When i came back that afternoon to pick up my spark plugs, i asked the tech what was the cause of the spec V being toed in, the tech told me the guy had put "Split fires" in his car. DOH!

Frosty

Well I got the codes at Autozone today.

P0505
Idle Control System Malfunction.

Alright any Takers?

It actually had thrown this code twice.
I had him erase the codes for now, figured it would throw them again if it was still an issue

cobymoby

iTrader: (2)

IMO Irridium plugs are a crap shoot. They seem to work on some applications but wreak havoc on others. I've seen one break appart on the dyno and basically destroy the motor.

I'm running HKS irridium plugs on my MR2, they gave me 5HP across the board on the dyno and really cleaned up my graph. I can't really say if they were the plugs that helps, or just the fact that that old NGK plats were a little worn. Before anyone flames me for spending $16 per plug on the HKS plugs, HKS gave them to me for free.

theMax

From the service manual

DTC P0505 IDLE AIR CONTROL VALVE (IACV) — AUXILIARY AIR CONTROL
(AAC) VALVE

On Board Diagnosis Logic

Malfunction is detected when
(Malfunction A) the IACV-AAC valve does not operate properly,
(Malfunction B) the IACV-AAC valve does not operate properly.
Possible Cause

MALFUNCTION A

I Harness or connectors
(The IACV-AAC valve circuit is open.)
I IACV-AAC valve
MALFUNCTION B

I Harness or connectors
(The IACV-AAC valve circuit is shorted.)
I Air control valve (Power steering)
I IACV-AAC valve
DTC Confirmation Procedure

NOTE:
I If “DTC Confirmation Procedure” has been previously
conducted, always turn ignition switch “OFF” and wait at least
10 seconds before conducting the next test.
I Perform “PROCEDURE FOR MALFUNCTION A” first. If 1st
trip DTC cannot be confirmed, perform “PROCEDURE
FOR MALFUNCTION B”.
I If the target idle speed is out of the specified value, perform
“Idle Air Volume Learning”, EC-67, before conducting
“DTC Confirmation Procedure”. For the target idle speed,
refer to the “Service Data and Specifications (SDS)”,
EC-643.




This system automatically controls engine idle speed to a specified
level. Idle speed is controlled through fine adjustment of the
amount of air which by-passes the throttle valve via IACV-AAC
valve. The IACV-AAC valve changes the opening of the air by-pass
passage to control the amount of auxiliary air. This valve is actuated
by a step motor built into the valve, which moves the valve in
the axial direction in steps corresponding to the ECM output signals.
One step of IACV-AAC valve movement causes the respective
opening of the air by-pass passage. (i.e. when the step
advances, the opening is enlarged.) The opening of the valve is
varied to allow for optimum control of the engine idling speed. The
crankshaft position sensor (POS) detects the actual engine speed
and sends a signal to the ECM. The ECM then controls the step
position of the IACV-AAC valve so that engine speed coincides with
the target value memorized in ECM. The target engine speed is the
lowest speed at which the engine can operate steadily. The optimum
value stored in the ECM is determined by takig into consideration
various engine conditions, such as during warm up,
deceleration, and engine load (air conditioner, power steering and
cooling fan operation).

COMPONENT DESCRIPTION

IACV-AAC Valve

The IACV-AAC valve is operated by a step motor for centralized
control of auxiliary air supply. This motor has four winding phases
and is actuated by the output signals of ECM which turns ON and
OFF two windings each in seqeunce. Each time the IACV-AAC
valve opens or closes to change tha auxiliary air quantity, the ECM
sends a pulse signal to the step motor. When no change in the
auxiliary air quantity is needed, the ECM does not issue the pulse
signal. A certain voltage signal is issued so that the valve remains
at that particular opening.

NuJerseyDrive

iTrader: (3)

theMax, does the manual illustrate and describe how to replace the IACV-AAC Valve? I've ordered this part today and know of someone who has the SM. I would like to do this myself rather than pay someone if it's not too difficult to replace.

theMax

Its a round cylinder looking thing right under/in front of the throttle body.

No step by step for valve removal. Take a look under your hood and see what the job looks like. Looks like the power steering can also be a cause.

NuJerseyDrive

iTrader: (3)

Gotcha, thanks.

ZIPPIN

iTrader: (32)

i have to agree with coby. irridium did not do anything but cause trouble for her...

Frosty

Well so far the Iridiums are holding up, they seem to be working good, I thinked I fixed the problem with the Service Engine Light. I forgot when I replaced the plugs I tightend up the the throttle wire, I think I tightend it too much and ever sense I losened it up things seem to be running smoothly. On a side note I just blew my 3rd set of PIAA PLasmas, any suggestions on a longer lasting good bulb?

panda_1

iTrader: (4)

im sorry to say i disagree with the statement you posted. for you see i am running bosch platinums and have absolutely no problems with them. "knock on wood".

callmezeus

"Knock on Wood" I even see an increase in gas milage; now I can turn the overdrive off a little more.