Nmax92

`sup guys. I have a problem. when I turn on my A/C the idle on the car dips below 500 and fluctuates +/- 200rpm, plus the car is very sluggish when moving off. When the A/C is off, its a bit better, but not completely normal.

Also when I start the car, it revs up to 2K rpm then drops the to 1K then to about 250rpm sputters and dies. It will start right up and have trouble staying above 700rpm, i would have to race the engine.

I'm guessing its my MAF or my belts needs adjusting, I haven't check it out yet. Any ideas guys?

Greeny

iTrader: (43)

Sounds like the maf to me...

Unplug the maf harness,then start it up,if the funky idle problem goes away,bingo..

Note:The engine will not rev over approx. 2500rpm while the maf is unplugged,and your check engine light will come on while the maf is unplugged.

mofoaka

intake air control valve may need some cleaning??

Nmax92

mygreenmax94, if your method works should I spray the MAFwith electrical cleaner

Greeny

iTrader: (43)

It's worth a shot,i tried it with mine,but it was a no go..

Alex_V

CRC makes a MAF cleaner, its only a few bucks. I used it on mine a while back and it ran a little smoother.

~Alex

internetautomar

iTrader: (30)

I'd blame the IAC first.
or possibly bad injectors
not enough detail to make a close diagnosis IMO

92 Max

There's also an idle up control for the A/C that may not be increasing the idle when the A/C is turned on. This would cause the engine to drop too low at idle. The other things may be contributing.

Nmax92

92 Max, do you where is the idle control for the A/C?

Greeny

iTrader: (43)

The FICD [fast idle control device] selonoid is a integrated part of the idle control valve..



This part is located under the throttle body..


BTW,did you check the maf yet?

Nmax92

no, not yet. I'm going to check the maf today. I'll post later with the results.

Nmax92

sorry fellas, I didn't mention this is for a gxe. the se on my profile is my first baby.
Mygreenmax94, I checked the MAF. on start up the car was running quiet and smooth(with the MAF unplugged) like it came fresh from the dealer.

When I plugged it in thats when it started sputtering. check this out, with the MAF unplugged I turned the A/C on and the car just died. IS that stilll a maf problem?

I adjusted the idle to factor specs, still the same problem.

Greeny

iTrader: (43)

Hmmm...

Here are the results of my tests on my two maximas..SE/w VE engine/GXE/w VG eingine

Both with good mafs/Iacv's

SE..

1. Unplugged maf runs as normal/stumbles momentarily when maf is plugged back in wiith engine running,then recovers..

2. Still runs fine with maf unplugged/w AC on..

--------------------------------------------------------------------
GXE...

1. Runs as normal with maf unplugged..Stumbles but recovers when maf is plugged back in/w engine running..

2. Dies when AC is turned on/w maf unplugged...

----------------------------------------------------------------
According to the fsm,the VE engine iacv/ficd unit allows for more air when the AC system is turned on..

But is says nothing about the VG engine iacv/acc unit allowing for more air intake from the iacv/acc unit when the AC system is activated..

Unless someone with more knowledge of the vg iacv system chimes in,i'm still calling the maf as your problem..

internetautomar

iTrader: (30)

start with a used MAF that you know is good, since it clearly has a problem. It mau not be your only problem though.

Nmax92

I defintely think its the maf also. I cleaned the terminals and the filament on the maf, I clean the iacv, tightened the alternator belt(thought the system isn't charging enough...preventive maintenance), and adjusted the idle again.

so far its running ok. The next test is to start it in the morning if I get the same result I'm going to get a new maf and move on from there.

Nmax92

I had the smae stalling on startup this morning. Its confirmed it is the maf.

TxMaxima93

How in the sam hill do you just unplug the thing I just want to check it.

Greeny

iTrader: (43)

Use a small pick or other suitable tool to push the metal clip open while gently pulling back on the connector

'93maximaGXE

iTrader: (1)

haha, i thought you had to take the screws out to take it off.

TxMaxima93

Naw I wasnt going to take the screws off I learned a lesson by doing that on something i couldnt put back

x91max

if u disconnect the maf and the car dont start no more until you plug it back in whats that mean?

TxMaxima93

Well for me I am hoping its the MAF or the knock sensor this loss of power is baffling. When I went to get it tuned the guy told me I need to spend $1200 on a compression test and it would take 3 days. I was like hmmmm let me get back to you.

x91max

you can do a compression test urself given 3 hours of work. mine has its good days and its bad. sometimes itll have all the power in the world and others it will barely be able to start off.

cachejob

iTrader: (2)

time for a new mechanic...

TxMaxima93

I disconnected the MAF and the car just dies. I try to restart it and i have to rev it to keep it running.

internetautomar

iTrader: (30)

check for a vacuum leak.

TxMaxima93

Amazing I just replaced my MAF this morning I havent reset the ECU yet but I can already see the difference my car now has the power back. That's crazy that one sensor just makes the car run like crap when it goes bad. Thanks for all the help. Now I'm off to fix the power locks

TxMaxima93

Is the dealership the only place you can get the ECU reprogrammed

Greeny

iTrader: (43)

Reprogrammed?the dealer can't anything but check/clear codes from your ecu,which you can do yourself for free..

JWT can remap your ecu for about a gazillion bucks.

traxtar944

iTrader: (12)

My car dies when the MAF is unplugged, too. That's because of a vacuum leak? What is the procedure for diagnosing where the leak is?

Hmm...I found that the vacuum tube going from the intake manifold to the water **** solenoid was disconnected. This is for the AC unit, but could it be causing the engine to stop when removing the MAF? Because it still stops running when unplugged.

TxMaxima93

Service Request for Sterling McCall Nissan in Houston

If its just a reprogram with no other work performed $105.00

Thanks,
Bruce


Just wanted to make sure that this is about avg as far as the price goes.

Greeny

iTrader: (43)

Reprograms via consult tool are for later OBDII ecu's,not our ecu(OBDI)

Tquick

Any vacuum hose that is disconnected is going to cause a vacuum leak, regardless of what it is supposed to be connected to, and any vacuum leak is going to cause the engine to run poorly.

DaWifey's90

iTrader: (3)

i have the exact same issue on my 90 SE VG. turn the AC on an it feels like i'm towing a rig, turn off the AC and almost immediately it feels like i picked up 4 more cylinders.

i'll have to test the MAF

here's my ?
is it possible that the added load of engaging the compressor will exacerbate an existing condition that otherwise may not be severe enough to be detected?

internetautomar

iTrader: (30)

short answer: Yes.

nimmy

I'm having the same prob, went and took off the plug on my maf... it ran better at about 500rpm with no loss in rpms.. when i tryed to give it a little gas it went up then down and caught itself at 500rpm (cold engine). I plugged it back in and it completely went bonkers on me and started idling rough/trying to pull me while i was had my foot on the break in drive every couple seconds....

So I guess thats my maf, autozone cost.. 205.00 dollars, cleaning price, a few dollars? Are there any instructions on how to clean? I have a 95 btw, just found this post through search.

Greeny

iTrader: (43)

You could try to clean it,worth a shot..

Cleaning instructions-->http://videos.streetfire.net/video/4...6f015c3dac.htm

If cleaning don't work,try a used unit from the classifieds section here on the org..

Classifieds link-->http://forums.maxima.org/forumdisplay.php?f=61

Joe Rockhead

Hi Guys.
My 94 GXE has just started to do the same "stalling when cold","rough idle when a/c is on". I cleaned iacv (was pretty clean inside), but I think that the step motor attached to the front of the iacv may be bad! Any test for that? Any Ideas?

Thanks,
Joe

DaWifey's90

iTrader: (3)

holy cow people!!!
i pulled my MAF sensor and simply blew into it and reinstalled it. I CAN'T BELIEVE THE DIFFERENCE!!

so i picked up the MAF sensor cleaner and even more results!!!

i switched back to the stock cleaner (from an oiled-gauze type) and i almost have my chirp-in-2nd back!!

i know it has more problems but i can't believe the difference cleaning out the MAF made.

thanks yet again guys!!!