J30 Stalling at Idle - Oxygen sensor?

[emgtech]

My 1997 J30 has started stalling and dying when it is idling. It will be at 800 and then it will waver a bit and crash. The idle is not rough - it just quietly dies. This does not happen all the time.

Soon after, the check engine light came on, throwing up P0325 and P0156. Could the oxygen sensor failure (P0156) be causing the dying at idle?

Strangely, when I have the temperature control on, the idle is rock solid at 800 and never dies. But when I turn it off or when I turn on my lights, it drops a bit and wavers more, occasionally dying.

Any help would be greatly appreciated!

Thanks,Evan

[driverdriver]

One of your codes is the rear oxygen sensor. Did you change the right 02 sensor? There are two.

The other code is your knock sensor.

zerothread/217492

[alex61089]

I'm going to attack this from two different ways. First I'd like to say that with these cars, the unusual or unexpected tends to happen. I.e. parts that normally wouldnt cause a certain malfunction do. Perhaps the knock sensor is retarding the timing so bad that the car decides "im going to shut off" I'm not too knowledgeable to the knock sensor so i'm not sure.However, a bad oxygen sensor I believe wouldnt cause you to stall out, unless perhaps all of them were bad or say 3 out of 4 are. But one? no. I would check your mass air flow sensor.

I had the Same problem as you did. It would often stall out on me with no indication, just some fluctuation in the idle and bam! it shuts off. Buy MAF cleaner, or even electronic parts cleaner (CRC makes both) and just double check to make sure its zero residue and clean your MAF and see if that fixes the problem.

Does the car turn on immediately after it shuts off? or do you have to keep cranking it? Does it stall out when you put your foot on the brake, or stopped i.e. Lights, stop signs, ect.Or, does it stall out when driving?

[emgtech]

Thanks for the information. I'll give the MAF a clean and hope that helps.

After it shuts off, the car restarts, but if I let it idle too long it usually shuts down again. It usually only stalls while stopped - foot on the brake - though a couple of times, it has stalled while slowly cruising - no gas - into a turn, like a driveway.

[yodawill2000]

Replace the Fuel filter lately ?

[GerryO]

Replacing the O2 sensors should improve your highway gas mileage.

Go here to cure your idle/stalling problems.

http://home.swipnet.se/e-solutions/IdleTech.html

Adjusting the idle speed up just a bit, simulating what happens automatically when the alternator and/or AC increase the load on the engine, could get you by for a while, but will also put more strain on the transmission and brakes, and worsen your mileage.

The failed knock sensor will change the engine timing below 3 or 4k rpms, and that could also be part of the problem.

[alex61089]

Thanks for the information. I'll give the MAF a clean and hope that helps.

After it shuts off, the car restarts, but if I let it idle too long it usually shuts down again. It usually only stalls while stopped - foot on the brake - though a couple of times, it has stalled while slowly cruising - no gas - into a turn, like a driveway.

I would aim for the mass air flow being dirty then perhaps the fuel filter needs to be replaced but first go with the cheapest method just make sure the mass air flow is completely dried before you put it back on, of course the stuff dries very fast so you should have no problem.

[emgtech]

Thanks for all the help. I'll give it a shot this weekend.

If these cheaper fixes don't work and I have to replace the oxygen sensor (left hand rear/after cat, I believe) is there anything special I should know - is it a tricky or difficult sensor to replace on the '97 J30?

Thanks again,Evan

[GerryO]

Thanks for all the help. I'll give it a shot this weekend.

If these cheaper fixes don't work and I have to replace the oxygen sensor (left hand rear/after cat, I believe) is there anything special I should know - is it a tricky or difficult sensor to replace on the '97 J30?

Thanks again,Evan

Replacing the O2 sensor should protect/extend the life of the catalytic converter, in addition to improving gas mileage. Each side is a bit different. Spray the threads wth some penetrating oil and give things time to soak in.

[emgtech]

Thanks for the advice. The gas mileage is a bit low.

Is this the right one?http://www.autopartswarehouse....gan=1

[GerryO]

I replaced both sides, when one started to fail and ordered them from here:

http://www.sparkplugs.com/resu...4&y=7

Thank you for your order at Sparkplugs.com. Below is a summary of your order for your records:

Date Placed: 9/27/2008Referred By: Nico Club Forum

Following is a summary of your order:2 - Denso OE identical O2 sensorStock Number: 234-3087Part Number: 234-3087Unit Price: $59.88Extended Price: $119.76

Subtotal: $119.76Shipping & Handling: $10.54 (UPS Ground)Tax: $9.28Total: $139.58

The 7.75% tax listed above is applicable for CA residents only.

OEM are Bosch and you may be able to find either brand cheaper somewhere else.
Modified by GerryO at 5:51 PM 9/25/2009

[Victor]

Quick fix, just leave the air conditioner on all the time. My 94 J30T idle speed fluctuates up and down with the air conditioner off, but doesn't stall out, but is rock solid with the air conditioner on. Maybe the engine needs some load on it to run at a stable idle speed.

[yodawill2000]

That's fixing the symptom instead of fixing the problem.Not to mention a big hit in gas mileage over time.

[Infinitiguy19]

Why not just unplug the O2 sensor(s) that's causing the problems?

Sure its not a permanent fix in any way, but beats having the A/C on in already cold temps.

[GerryO]

Doubt that failing O2 sensors are causing the low idle speed/stalling problems. Sounds more like other factors, including the KS code and its' affect on engine timing.

Simply turning the idle adjustment screw to increase the idle speed could cure the stalling problem, but then the ECM will no longer determine the low idle speed, and I suppose brake and transmission wear will increase too.

[yodawill2000]

I concur..

[emgtech]

Thanks for all the help. I cleaned the MAF over the weekend and that seemed to help a bit. Now, I can turn the A/C off. Also, the idle has dropped a bit, even with A/C, so that it is usually stable around 600. However, about half the time, the car still occasionally goes into fits of wavering of stalling for the first few minute. But after this initial fit, it seems to settle.I noticed, before the MAF clean, that the car was also driving a bit rough, which seems to be continuing.

Anyhow, I ordered a replacement o2 sensor from Bosch, which I plan to install as soon as it gets here. Also, the car is relatively new to me, so I don't know the maintenance state of a lot of parts. I think the fuel filter, as some folks mentioned, might be a good next target.

I'm hoping that the knock sensor code does not reappear, as I really don't want to replace it.

Thanks,Evan

[brettsdad]

had similar symptoms. fairly common for the j30. i have a 96 with 3 codes from the cel. 2 o2 sensors and a bad egr. i didnt and still havent messed with those. from searching on this forum i determened that it was the mass air flow sensor. changed it, runs fine. you can find a working used one for troubleshooting purposes on ebay fairley cheap. you may want to buy a new one though if it turns out that it is the maf sensor cuz the ebay one will likely last a few months or even weeks. also do not try to pry it open unless you are very skilled with a soldering iron.

hope you get it fixed. does it only die at stop sings, low speeds, parked? or does it ever die on the highway? mine always ran fine at speed, would only die at low speeds or when stopped.

good luck.

[reagd]

i also had similar symptoms on my oxygen sensor but thanks to my brother you have time to fix the issue, he only clean the MAF then the problem just got away.

[emgtech]

Just realized that I forgot to follow-up on this post:
Turns out the MAF was finished. I replaced it; car has run great since.

Evan

[GerryO]

Started my engine after a new water pump/timing belt/oil seals/etc session without the plastic intake tubing connected to the throttle bodies. It started, ran for about 15 seconds, sputtered and died. Made my wife sort of happy at the time. Suppose no air moving past the MAF sensor tells the ECM that the engine doesn't require any fuel either.

Also know that the engine will crank, but not start if the TPS is disconnected.