# '94 Altima sputtering problem, egr, obd-codes.



## jbleau (Aug 13, 2010)

Hey all,

My girlfriend has been recently having problems with her 1994 Altima. She'll be driving along and seemingly randomly it'll start to sputter really badly. If she accelerates too hard it raises the RPMS then drops quickly and does this over and over really quickly at a consistent frequency. 

I'm not a mechanic but I always try to learn new things about cars. I popped the hood and I could tell that it might have something to do with the EGR. I smelt almost pure gas. I fiddled with the EGR to see if it was getting stuck and maybe it need cleaned. 

I got a second opinion from someone who knows a little more and they said that it might be that, but it could also be a sensor and that I should have the scan-codes pulled.

I took it to Autozone and found out that the 94 is just a few years short of having OBD-II implemented and that they couldn't scan it. Now here I am looking up scanners online for OBD-I systems and I've learned that I'll need a specific plugin for the Altima, because OBD-1 wasn't as standardized.

First, if anyone has had similar problems and might know what it is, I would love any advice.

Second, if I need to pull the scan-code, is this what I'm looking for? Nissan Consult ECU Diagnostic Interface - Gift Finder Online

I'm a computer tech so getting the computer software end to work should be no problem, but I'm just not 100% if this is the right connector for the 94 altima.

Best regards all, and any help at all is greatly appreciated. If you know what's wrong and happen to live in SE Michigan I'll buy you a good brew. 

JB


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## lilfoo22 (Mar 22, 2010)

if the egr is stuck open it will make it idle and or run rough. if an o2 sensor is bad it will make it run bad also. comp cant detect how much fuel to accurately give it so it just guesses. in result smells like raw fuel. but in your case id get those codes before you waste any money throwing parts at it and hoping it fixes it. 

i know most obd-1 you can jumper wire and count check engine light flashes for codes. but not too sure about your car.


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## rogoman (Dec 16, 2004)

jbleau said:


> I smelt almost pure gas. I fiddled with the EGR to see if it was getting stuck and maybe it need cleaned.
> 
> Second, if I need to pull the scan-code, is this what I'm looking for? Nissan Consult ECU Diagnostic Interface - Gift Finder Online
> 
> I'm a computer tech so getting the computer software end to work should be no problem, but I'm just not 100% if this is the right connector for the 94 altima.


If you smell gas, then there is an external leak; a bad EGR will not cause this.

The sputtering can be caused by an EGR that gets stuck open. Disconnect the vacuum to the EGR and drive the car around for a while to see if the sputtering clears up; if it clears up, then the EGR valve is dirty.

You can do an ECU code readout without using any fancy scan code hardware/software. Download a copy of an FSM for your car from:

Nissan Service Manuals


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## double b26 (Aug 21, 2010)

hey, thanks for the service manual link. i just got a 93 altima today, and was looking for one earlier, but couldnt find it. awesome. i had to go with the 94 model book though, but it should be close enough.

to the OP, you might start by looking around the injectors for a leaking seal. also look at your fuel feed and return lines. you should see something wet if there's a leak. 

however, if the egr is putting too much egr gas into one of the chambers, it can make it not detonate, or not completely anyway, and will result in unburnt fuel flooding the chamber. it will 'wet soak' the plug, and if there is enough gas in there, you can smell it outside of the engine. 

the egr system recirculates unburnt fuel back into the combustion chamber to keep the cat converter from have to work as hard. they can get clogged with carbon. also, the egr intake runners can clog as well. some engines (like honda f22's) have removable plugs that you can pull to clean out the port passages leading to the combustion chamber. 

on my honda, there is an egr block plate that you can put in place of the valve, and do away with the system completely. you'll gain a couple horses, the intake will stay clean longer, but you'll also have a chronic CEL lit up. hey, you cant win 'em all!


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