# Fluctuating Idle problem... help!



## littlebadboy (Jan 25, 2005)

Hi guys! I have a 1993 Sentra ECCS. I think its a B13. I have a problem with my car. It has a very erratic idle. Whenever I accelerate or even rev high and immediately release the accelerator pedal, the rpm needle would dive and shut off the engine. However, acceleration and running at high speeds are a-ok.

I hope you guys can help me coz it has been bugging me for quite some time already. I have to step on the brakes and gas at the same time just to compensate. I already tried to adjust the idle screw but no improvement has been incurred. Thanks!


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## toolapcfan (Jul 10, 2002)

Welcome to the club. I've been trying to solve this problem for 2 years now. By the way, your car is a B13, all sentras and NX's made between 1991 and 1994 are B13's and ECCS isn't a model that's just what they stamp on the intake manifold for the GA16DE. Your model is either E, XE, SE, LE, or GXE. I'm not trying to hassle you, just informing you so that some jerkoff doesn't come in here and act like they're a genius for pointing those things out to you. Actually, some jerkoff will probably still come in here and do that, so just be prepared for that.


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## Catman (May 21, 2004)

> It has a very erratic idle. Whenever I accelerate or even rev high and immediately release the accelerator pedal, the rpm needle would dive and shut off the engine. However, acceleration and running at high speeds are a-ok.


I had hesitation, stumbling, and sometimes my car stalled when the compressor turned on. First, I increased the idle with the idle screw. No help. Then I removed the part that the idle screw is located in. It is called the Idle Air Control Valve Unit. Mine had a lot of carbon built up, causing it to not respond, or adjust appropriately. Do a search. I posted pictures after cleaning it, since I had the problem for years. Also, cleaned the throttle body and changed the fuel filter. The combination produced great results. I can finally merge into traffic or stop and accelerate without the engine wanting to stall. Also, my running at high speeds was OK. It was just getting up to higher speeds that was the problem. Hope that helps.


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## Modemagic (May 13, 2004)

I second catmans thoughts... also, check the timing. The majority of my problems were timing related.


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## StevenLK (Jul 15, 2002)

i had that happen to my ga16 b'4, it was a vacum leak, and sometimes just shut off because bad fuel injectors. but urs maybe a difrrent problem. i was just suggesting what the problem was with mine.


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## littlebadboy (Jan 25, 2005)

Thank you everyone for your information!



Catman said:


> I had hesitation, stumbling, and sometimes my car stalled when the compressor turned on. First, I increased the idle with the idle screw. No help. Then I removed the part that the idle screw is located in. It is called the Idle Air Control Valve Unit. Mine had a lot of carbon built up, causing it to not respond, or adjust appropriately. Do a search. I posted pictures after cleaning it, since I had the problem for years. Also, cleaned the throttle body and changed the fuel filter. The combination produced great results. I can finally merge into traffic or stop and accelerate without the engine wanting to stall. Also, my running at high speeds was OK. It was just getting up to higher speeds that was the problem. Hope that helps.


Maybe I should try that.



StevenLK said:


> i had that happen to my ga16 b'4, it was a vacum leak, and sometimes just shut off because bad fuel injectors. but urs maybe a difrrent problem. i was just suggesting what the problem was with mine.


I am suspecting a vacuum leak and timing issues too. How do I check these?



toolapcfan said:


> Welcome to the club. I've been trying to solve this problem for 2 years now. By the way, your car is a B13, all sentras and NX's made between 1991 and 1994 are B13's and ECCS isn't a model that's just what they stamp on the intake manifold for the GA16DE. Your model is either E, XE, SE, LE, or GXE.


Thanks for the info. Here in the Philippines, my model is called a Sentra Super Saloon ECCS. It has the GA16DE engine with 4-doors.


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## Solidox2k (Jan 21, 2004)

> Thanks for the info. Here in the Philippines, my model is called a Sentra Super Saloon ECCS. It has the GA16DE engine with 4-doors.


heh, "Super Saloon" . i like that lol.  

yea, i third catman. i took his advice, its real easy, and it solved that problem with mine right after i finished. 

have the timing checked just in case, couldn't hurt. i myself dont really know how to throughly check for vacuum leaks (properly). i just check hoses for deteriation, cracking, ect... or listen for odd whistling noises under load and idle. problem with me, is im real lazy and it seems like there's 40+ hoses under there :/

as for timing, i've never done it myself so cant really comment on that.


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## littlebadboy (Jan 25, 2005)

Hey guys, a mechanic told me it had something to do with the Servo. Something about air/gas adjustment that can only be electronically done.

What do you guys think? Thanks!


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## new94 (Jan 9, 2004)

I'd just start with the usual probs and go from there, clean the iac motor, check timing, and what happened with mine was the mass air meter plug came loose and this caused the car to stall everytime the throttle was let off at a light etc.


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## littlebadboy (Jan 25, 2005)

new94 said:


> I'd just start with the usual probs and go from there, clean the iac motor, check timing, and what happened with mine was the mass air meter plug came loose and this caused the car to stall everytime the throttle was let off at a light etc.


thanks for the advice. where can i locate the mass air meter plug?


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## redhat-z (Feb 14, 2005)

*Possible stumble fix*

My se-r does the same thing. I was thinking it was the EGR not regulating the amount of exhaust it draws in and sending way to much back to the intake. I am removing the whole EGR assembly sometime soon anyway. We don't have yearly emmissions testing here anymore plus I think EGRs are a waste of time and hp when running 93 octane.


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## RBI*04 (Sep 10, 2004)

my GA16 4spd manual drops the rpms to the point where its _just about to_ stall when ever i rev it then let off the gas, but not once has it stalled (its stalled plenty of times, but they were isolated incidents)


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## new94 (Jan 9, 2004)

Mass air meter is where your air filter is hooked up to, there's a plug about mid way to your intake just wiggle it or unplug and plug it back in to be sure it's tight.


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## etvaugha (Apr 11, 2004)

RBI*04 said:


> my GA16 4spd manual drops the rpms to the point where its _just about to_ stall when ever i rev it then let off the gas, but not once has it stalled (its stalled plenty of times, but they were isolated incidents)


I know this sounds dumb, but check your fuel filter. I had the same problem and surprisingly a new fuel filter fixed it. You could also try cranking up the IAA.


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## littlebadboy (Jan 25, 2005)

Thanks for all your advices!

I tried to change the plugs. They're still ok, except that the tips were sooo BLACK! What does this mean?



etvaugha said:


> I know this sounds dumb, but check your fuel filter. I had the same problem and surprisingly a new fuel filter fixed it. You could also try cranking up the IAA.


Forgive me for my ignorance but... what's an IAA?


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## littlebadboy (Jan 25, 2005)

Hii guys! Here's an update.

I used to have idling problem. If you release the throttle, it would die. I raised up the idle at around 1,500rpm without aircon. At first, it worked but would still later on die out.

I tried cleaning the IAA. I took it off and sprayed some Carb cleaner into it. I did not dismantle the whole thing though. I took off the Air Cleaner and the tube going to the ECCS. I cleaned the air filter. I saw a sort of an Air Sensor which comes right after the filter. I did not dare try to clean it fearing that I might break it. It looked so delicate. I pumped in a lot of Carb Cleaner Spray into the ECCS thingy. I cleaned up the plugs. I screwed everything on afterwards.

Afterwards, I opened up the distributor cap. I found out that the rods and the rotor itself were already corroding. I cleaned it up a bit.

I assembled back everything and then started the engine. It sounded smoother even when i adjusted idle lower drastically. Idle now is at 800rpm. Gasoline mileage is now better. I took it for a spin and everything seems better.

I tried to restart the engine in the following morning. The idle would still die out if you release the gas pedal but would get better when the engine has been warmed up.

Things are definitely better than before except for the engine dying out if I release the gas pedal specially when the engine is not warm yet.

If I am correct, perhaps I missed out something. Any tips? Can I clean the Airflow sensor? How? Should I replace my distributor cap and cables too?

Thanks to all of you. Can't wait to work on my babe again soon.


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