So...

After I:

- replaced the spark plugs
- fuel filter
- #6 ignition coil
- #6 injector
- re-cleaned air filter
- cleaned IAC valve
- cleaned MAF sensor
- cleaned throttle body
- ran many cans of injector cleaner

I found that it wasn't any of the above. I now have two spare injectors, a couple of good coil packs, and 6 good G-Power NGK spark plugs.

What was causing the poor idle on my 99? After reading about someone else with a 99 having a pinched intake manifold gasket, and I was also hearing a loud vacuum sound, I took a can of WD-40 and spraying around my intake with the car idling.

WOOOF!!! Right around the rear part of intake #6 the gasket was pinched allowing air to seep in. @#*#$*$*!!!$*$*!@@

Anyways, loosened the two rear manifold bolts, took off the front 4, and shimmied out the old pinched gasket and put a new one in after I cleaned off the intake with alcohol and a long q-tip and then blew compressed air to dry it off.

I wonder how many of us are having the EXACT same problem? Bad idle, but you've put in new coils, injectors, plugs, cleaned the TB,IAC,MAF, air filter, when it's a @@($%* poorly designed 2 dollar gasket Nissan put on our manifold.

Anyways, she's idling like a Lexus. Problem solved.

 

pics please ?

 

How can you describe the poor idle that you had ? You felt vibration in N or D ?
Also pics would be highly appreciated

 

good info,
have few Q's ,
have you ever removed the Intake manifold for any reason, and maybe disturbed the gasket by any chance, or the IM have never been removed
and the cause for pinched gasket is something else?

and how do you exactly "and shimmied out the old pinched gasket "

thanks !!!

 

Sounds like he didnt undo the egr and just lifted the upper IM just enough to remove the gasket.

 

You guys need to go here and suggest advice for the vacuum leak.

http://forums.maxima.org/showthread.php?t=496091

Same problem.

 

Great information

 

Thank you.

I will follow your advice and check for vacuum leaks before checking for bad fuel pressure on my car.

Lately it has been idling erratically, on some days just fine, on some days good RPMs but the engine shakes a little, and on the worst days the RPM's are extremely low at idle.

Do the amps have anything to do with it? My battery is really low-amp and I do notice that when I put on a strain on the electrical system by turning on all the lights at once the RPMs drop slightly.

 

Fork,

I think this is my problem as well, i sprayed some T-body cleaner around the area of hte intake manifold where you described and the rpm's actually kicked up a little so I guess i have a leak there. Did you have to take everything off of the upper manifold to replace the gasket? I have never done this on the maxima. Thanks.

Chris

 

i figure that if you just undo the bolts of the upper IM and just lift it right off a little and slip out the old gasket