96 Altima rough idle

I have a 96 altima with 65K miles. It has a very rough idle at about 500 RPMs. It idles better with the ac on but then the RPMs go up to 1K.

At low idle it sometimes stalls and sounds real bad at the exhaust. There isn't any black smoke.

The performance seems to be OK.

I have changed the sparkplugs, dist. cap and rotor and inspected the plug wires. I also took the injectors out and cleaned them with brake cleaner. Nothing seems to help. The only light on is the airbag light. I took it to autozone and they said the computer would not pull any codes if the check engine light was not on.

I also inspected the distributor for any oil getting in but I did not take it apart. At the time I could not see how to look inside the distributor.

Any help would be appreciated.

James

i have a suggestion, but it would just be masking an existing problem, if in fact one does exist. you can raise your idle by turning the idle adjustment screw located between the 1st and 2nd intake runners. the car may run fine after doing so, but like i said, it will just mask whatever problem the car may be having. doesn't hurt to try it out tho :)

I thought about raising the RPMs but considered other options.

I noticed a set screw on the intake manifold that would limit the amount that the throttle body would close. It looked like a real pain to adjust because the set screw is upside down. I assume that is what you are talking about. If there is another one let me know.

Thanks for the info.


James

Also what should the idle be with no A/C on and the engine is up to temp? 500, 1K?

James

with no a/c on and engine at operating temp, normal idle should be around 650-750. i personally keep mine at 800 tho.

and as for the idle adjustment screw, all you need is a long phillips head screwdriver to reach down there. its not upside down (on my motor at least). its pretty easy to do.

you have a vacume leak at the intake manifold. Do yourself a favor and open the hood and you will hear a hissing sound at the backside of your engine compartment. Will sound like a tire with a whole in it. I have fixed 28 or 30 90-00 at 60k-90k miles with the same exact symptoms Replace Intake manifold gasket with O.E. Intake is aluminum and gasket is best removed with razor and bolts torqued in sequence.
The only thing is if you do not hear the hiss simply and carefully remove Idle control valve(located passanger side rear of intake 2wire connector and has coolant hose attached. Note that the gasket is 10 yrs old if it rips or tears leave it be and use some honda bond with the gasket when done cleaning (use a tooth brush and some injector cleaner what happens is carbon build up does not let the plunger seat and causes a vacume leak

DO NOT TOUCH YOUR THROTTTLE LINKAGE ADJUST ANYTHING THERE IS A BIG VACUME LEAK VACUME WHEN YOUR AC COMPRESOR IS RUNNING(LOADING THE ENGINE AND THIS CAUSES THE FAST IDLE TO ENGAGE AND MASKING THE LEAK) any good repair shop not dealer will find the leak in 5 min but will charge 1 hour 350 labor gasket 28 dollars 415.00 parts and labor and the best thing a warranty

Thaks for the info. I will check it out.

James

cool hope you are able to fix the problem cause you will save so much money in gas when you get that leak fixed

OK I can hear a hissing noise but it is near the throtle body. I assume it is just the airflow from the air intake. Just to make sure you know the engine is a 4cyl. I could not find the idle control valve. What is a good way to pinpoint the location of vacume leak?

Hi Bo Jangles

I believe you're right because mine is rough iddling and spending more gas than usual.

Can you recommend me a place where I can go to read and get more details about how to fix the problem? Pictures will be great !!!

Thanks in advance for your help !!!

Javier

where am i pose to get a new one? i swap my motor and advance my timing and my idle keep f*cking up so i adjust it i ran 14.5 on intake headers exhaust and my an auto and then my car keep choking and found out i need a new screw
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