2000 MaxSE stalling when not pushing gas

[bradfordrb]

Brief preface - my car is a 2000 Maxima SE w/ ~80k miles; I've replaced one of the 02 sensors (believe it was the second (rear) bank pre-cat) and changed out one of the ignition coils (#2) and all six spark plugs around 6 months ago.

Recently the car has begun to stall when I'm not pressing the accelerator - first noticed it when shifting to park after pulling into the garage, car died before I got to the keys. Since then it has repeated stalling SEVERAL times, usually in park or neutral. Car runs fine when driving and I can't hear/feel any symptoms of misfires. For example, I was driving around town and began a downhill.. wanted to see if it would stall with me taking my foot off the gas, rpms dropped but then recovered; so I shifted to neutral - almost immediately the rpms dropped and the engine stalled. The car has always cranked back up right after stalling (sometimes it stalls a second time but then cranks up).

Any help would be appreciated! I have not checked/changed the fuel filter/fuel pressure yet.

Thanks in advance,

[NISTECH]

since the car runs fine while in gear and does not stall I dont think its a fuel or spark problem but an idle air problem. Either to do with MAF input or IAC motor. try checking for codes, post your findings.

[carnal_c30]

check your MAF sensoryou might want to try cleaning the MAF and seeing if it makes a difference, make sure whatever you use is sensor safe, the MAF is pretty sensitive, maybe someone else can recommend using something, electrical parts cleaner maybe?

also what about vacuum leaks? check all your hoses, does the car idle in gear fine? My Lexus would idle a bit jumpy, but would drive fine, and then it would stall when I shifted it into neutral or park, there was a tear in one of my vacuum lines

[bradfordrb]

Thanks for the help guys, it was raining here today so the Autozone guys wouldn't take their OBDII readers outside. The check engine light wasn't on earlier; I managed to get it to turn on after I disconnected the MAF on my way to cleaning the throttle body butterfly valve area. The car seemed to idle ok w/o the hoses hooked up but the moment I closed the gap between the flexible air duct between the resonator box and the valve the car stalled - maybe it was coincidence.

Anyway, now the SES light is on and I'll try to have them pull the MAF code and reset it tomorrow. Should I expect other codes to be thrown from earlier even though the SES light wasn't on?

[bradfordrb]

only code thrown was P0100 = MAF; I suspect I made it throw this one when I cranked the car after unplugging the MAF Autozone reset the computer and it is still stalling.

I've attempted to listen and check for vacuum leaks, but haven't heard anything yet.

Since the car will run fine occasionally, I've begun to "try" to make it stall to see if that might help diagnosis. In neutral:I've found that if the car is running around 1000 rpm and I rev it up to ~3000 then let me foot off the gas, the engine almost always stalls. If I rev it up to 3000, then slowly drop it back to 1000 and let off the gas, it won't stall immediately, but may stall after a minute or two without throttle. While driving:Hard acceleration followed by a shift to neutral = stallGentle stop with no accelerator & rpms ~ 900 followed by shift to neutral/park = no immediate stall, but may stall after a minute or two.

[NISTECH]

with it idling try wiggling the harness coming off the right strut tower going to the engine,see if wiggling/twisting that kills the engine. If it does you probably have a broken wire in that harness loom. TSB exists for that, but several codes are usually associated with that failure.

[carnal_c30]

I would try cleaning the MAF with electrical parts cleaner, my friend with a 2000 max had the same exact problem, and he couldnt figure it out... MAF does get pretty dirty

its simple and you might as well just try it

and for vacuum leaks use a vacuum gauge to see if the vacuum jumps around, probably you would have a leak

[bradfordrb]

Well, after checking the wiring harness and vacuum hoses I decided to get the MAF changed. New MAF = problem solved! Thanks to NISTECH for his guidance.

[carnal_c30]

I hope you tried to clean the old MAF first, its a bit pricey, kind of alot to spend, 2000 Maxima MAFs are pretty hardy, only Maxima MAFs I've heard of having more than miniscule problems have been the 2002 MAFs...

oh well glad you have your problem fixed, still have your old one?

Well, after checking the wiring harness and vacuum hoses I decided to get the MAF changed. New MAF = problem solved! Thanks to NISTECH for his guidance.

[bradfordrb]

Well, I didn't really know what all to check on the old one.. I pulled it, checked electrical connections to the sensor and sprayed some computer motherboard cleaner on around the inside.. not sure if that did any good or killed it; but the car still stalled after reassembly. I was able to get a new MAF for ~$100 after tax etc.. but threw the old one in the trash (left the house yesterday ..