TKHanson

Folks:

I'm having serious issues but don't want to start replacing parts till I know the cause (if that's even possible).

140K miles, new plugs and MFS replaced 3 years ago. Original coils (ouch).

Occasionally, and I mean occasionally, my car will run really rough to where the maintenance light will come on. It clearly is missing (1 or maybe 2 cylinders). Sometimes when it's cold, sometimes when its hot. But often only lasts for one drive or in between drives.

Now a twist. Recently, it will not hold its idle. If I let off the gas at a stop light or even on a coast or downhill part of the free way it dies. This too is intermittent. Just got in my car at the airport after being away for 4 days and it didn't stall nor miss but when I was 30 min. into my drive the stall started again.

It's like there is some CPU that has a short or something. Is it possible some sensor works occassional and then other times fails? I never thought I'd see myself say this but I almost wish it always failed so I'd HAVE to address it.

I know I should replace the coils, but again, the failing cylinder only fails on occasion.

Thoughts?

dfj240

iTrader: (1)

Is the Service Engine Soon light illuminated? If so, retrieve the trouble code(s) from it. Even if it's not illuminated, I would still plug it in and see if there are any "ghost" codes stored. An outright stall is probably a bit more than A coil. Possibly multiple, but not just one.

-Nathan

TKHanson

I'll pull them asap and let the board chew on that. Thx.

morris369

iTrader: (1)

Mine was doing this a while back. I noticed it was happening only when I was on the lower half of the gas tank. I replaced the fuel filter and it went away, hasn't happened since, with your mileage it wouldn't be a bad idea to just replace that anyway. It is easy and not very expensive. My car runs and drives much better and has gotten about 2-3 MPG increase.

phatboislim

iTrader: (27)

i forgot what i did that fixed this

noahrexion

If you've had your SES flashing at you (even intermittently) then you will have a stored code (even if light is currently not on).

Definitely get that pulled - that should generally be step one.

Again, very common parts on these maxima's that go are: Coil(s), MAF sensor, crank/cam position sensor(s)

If by MFS you mean MAF and you did put in a OEM Nissan unit I would not suspect that part - although your mileage in those 3 years was not mentioned.

The SES codes will tell a lot.

TKHanson

As usual, you guys are good.

Ok, it was the mass airflow sensor that I replaced 3 years ago and I believe we used stock Nissan.

Just pulled the codes:
P0505
P0304 #4 Cylinder
P1320

I'm going and buying a new coil and replacing cylinder #4s tonight.

As for the fuel filter, I'll do that too. Need to look up how but will replace it. Regardless if that solves it, 140K it is time.

By the way, this MAF has about 45K on it.

noahrexion

Not that everyone does, but some folks just replace all of them at the same time.

If you just started getting the stalling issue (PO505) it may be a different issue all together. Read up a little using that as a search - some folks have had the IACV leak internally and screw up the IACV and/or ECU - a potentially very costly issue.

I would pull it and check it out for full function, if not bypass the throttle body (from coolant) all together.

TunerMaxima3000

iTrader: (4)

bypass it anyways, not worth the risk.

TKHanson

Replaced coil just now. Considering cleaning my IACV first, as a lot have noted on this thread:

http://forums.maxima.org/4th-generat...ning-iacv.html

You guys concern that is a good next step? By the way, I don't understand how to inspect the IACV for leaks, etc. Any help or threads that can help?

Spence

iTrader: (1)

Cleaning your IACV is never a bad thing, so I'd go right ahead and buy carb cleaner and grab an old toothbrush and have at it. They generally don't leak per say so I'd give it a good clean and see what happens.

Also don't rule out vacuum leaks to check for future reference.

TunerMaxima3000

iTrader: (4)

Actually, it's insanely common for them to leak.

It's also quite common for them to fry the ECU.

Perform a coolant Bypass the Throttle body, it's simple, it's cheap. Do it.

TKHanson

Is there some solid docs about performing a coolant Bypass to the Throttle body? I have to admit I've not researched it.

I'm buying gaskets tomorrow as well as cleaner. I'll use my wife's toothbrush and see if she notices the difference.

TKHanson

By the way, I was trying to conduct some of the tests that are well articulated on this thread:

http://forums.maxima.org/5th-generat...is-thread.html

However, I don't know my way around all the hoses on my Maxima. I don't know how to find the vacuum hose (power steering) that is near the air cleaner. I feel like an idioit asking but can someone take a picture of theirs or somehow direct me to that hose so I can check that it has proper vacuum and doesn't have a leak?

shortymust23

Cam crank position sensor if yours is 02-03 it's a recall check the recall section

TunerMaxima3000

iTrader: (4)

There are 3 Vacuum hoses that go into the big plastic 'baffle' by your air filter. One large, one medium, and one very small.

As I recall, the one you are testing is the MEDIUM sized one.

If you're unsure, you can trace the hose back to the Powersteering SWITCH, which is over by your Right (passenger) strut tower in the engine bay.

TKHanson

Great instructions. Found the exact tube. I was able to pull it and didn't notice a vacuum when at idle but when turning the wheel it had serious vacuum. Is that an issue?

Also, cleaned off the IAVC, but idle still will not hold. Would you suggested I simply replace the IAVC at this point?

Also, please take a look at the attached photo. I noticed this tube near the Transmission dip stick (within the red squares) that is NOT connected to anything. Should it be just "out there" like that?

(link to hosted photo) --> http://postimage.org/image/vk5fbd0dx/

TKHanson

Wait a second. I was going to price a new valve and relized they only sell the entire assembly. See link:

http://www.autopartswarehouse.com/de...QQSIAC278.html

So perhaps I need to get back in and pull the whole assmbly to clean everything? I pulled only the black valve that is held on with the two Philips screws. Does anyone know if there are possible faulty parts within the assembly that would lead me to believe I could have cleaned in there? Or said differently, is the only part that really fails and causes the 505 error code the black valve part. Thoughts?

TKHanson

Any thoughts on my photo I like above?