# 1994 Altima GXE dilemma



## alraqib (Oct 26, 2007)

:newbie:

Hi all, I bought my daughter a '94 Altima GXE w/AT as her first car recently and as is my custom I dove right in to get a maintenance baseline. That is, I tuned it up with cap, rotor, plugs and wires. I set the timing and RPM to spec, changed the oil, filter and trans fluid and dumped in fuel system cleaner and filled up with 93 octane.
I checked the on-board trouble codes and was showing "knock sensor" and "throttle position sensor" codes. I have replaced both and am now showing no trouble codes on the system.

So, here's the problem...
While the car starts and runs fine I'm finding that when I adjust the TPS to where I get "off" at closed throttle (rotating the top of the TPS toward the front of the motor), the engine revs high when shifting to 2nd gear and more so to 3rd. This only happens when accelerating very gently, seems to shift OK when I accelerate more aggressively. 
When I adjust the TPS the opposite direction (rotating TPS toward rear of motor), the idle goes up and sits between 850-950 rpms but the trans shifts perfectly.
I'm going to clean the throttle body tomorrow thinking that I may not be getting a true closed on the throttle body, but if that fails I' stumped.

Has anyone run into this? I'd really appreciate some ideas.


----------



## alraqib (Oct 26, 2007)

*1994 Altima GXE TCU question*



alraqib said:


> :newbie:
> 
> Hi all, I bought my daughter a '94 Altima GXE w/AT as her first car recently and as is my custom I dove right in to get a maintenance baseline. That is, I tuned it up with cap, rotor, plugs and wires. I set the timing and RPM to spec, changed the oil, filter and trans fluid and dumped in fuel system cleaner and filled up with 93 octane.
> I checked the on-board trouble codes and was showing "knock sensor" and "throttle position sensor" codes. I have replaced both and am now showing no trouble codes on the system.
> ...



Hey folks, I'm still trying to figure out the above problem, but have a few more facts that might be relevant.

I've come to find out that the motor and trans in this '94 is a actually from a '95 model. It was swapped out by the previous owner. 

My question: is the TCU from a '94 programmed differently than one from a '95?

I know the model numbers are different, ETC-N53 for the '94 and ETC-N400 for the '95.
Does anyone know if this could be the cause of above shifting problem? The current TCU is flashing 1 long and 10 short, so apparently all my sensors are OK.


BTW, I sprayed carb cleaner around the intake manifold and found leaks at #3 and #4 cylinders so I replace the intake manifold gasket and while I was at it I replaced the PCV and IACV. So, the engine is running very good.

Any input?


----------



## alraqib (Oct 26, 2007)

*1994 Altima GXE Update*

Hi everyone, just an update to say I got it all worked out.

I replaced the TCU with a '95 and dropped the trans pan and replaced the filter and refilled.
The filter itself wasn't too bad, but the magnets were a bit fuzzy. Cleaned it all out and refilled with about 4 1/2 quarts and now everything works great. Although nobody replied I did learn an awful lot about Altimas from this website, so thanks all...


----------



## Altima SSS (Oct 10, 2007)

alraqib said:


> BTW, I sprayed carb cleaner around the intake manifold and found leaks at #3 and #4 cylinders so I replace the intake manifold gasket and while I was at it I replaced the PCV and IACV. So, the engine is running very good.


I hear removing and replacing the intake manifold isn't very easy. Was there any tricks involved in that? Sounds like you did a lot of work that all worked out well.

I take it TCU = Tranny Control Unit? Where is that unit located?


----------



## alraqib (Oct 26, 2007)

Altima SSS, replacing the intake manifold is certainly no picnic, but definitely doable. And when it's all said and done it feels like you've rubbed your knuckles with a cheese grater.

The way I did it was first pull or disconnect all the ancillary stuff and then pull the starter and drop the collector. You can't get the collector plenum out thru the bottom, but you can move it around enough to make room to get to the lower manifold bolts.

I put it together the opposite way, dropping the collector in unattached, torqued down the manifold and then bolted on the collector.

I'd say, all told, that it took me about 8 hours, give or take.:woowoo:

The TCU is located under the passenger side kick panel, just in front of the door hinge. Tell you the truth, I'm not sure that replacing that had any effect on this, since all these things seem to be inter-related, but I got the part for $20 and it was easy to swap.
After I was done I reset the timing and re-adjusted the TPS and it all fell in line.

BTW, I thinks it's true about the Bosch plugs. I replaced them with NGKs and it seems to make a difference.

Cheers...


----------



## mensagero4u (Dec 8, 2009)

*94 altima TPS crazy code 43*

I have a Nissan Altima 1994 GXE 2.4 liter Automatic and I'm having some problems with my car. The problem is that the something is messed up and I don't know what it is. I install new distributor, new Knock sensor, new Throttle position sensor, new spark plugs and new ECU. 
Here is the problem; the car runs perfect in the morning wile is cold.
After reaching normal temperature I park the car for five minutes and that’s when the problem starts.
The car runs fine after getting on 2nd gear but ones you get to full stop the car runs like trash.
I read the code on the ECU and is giving me a code 43 > 3 short flash and 4 fast flash after TPS, I did change angle but at the center of the TPS is were best work.
Every time I reset the ECU the code 43 is back.
Timing is perfect and injectors are working well, the distributor or connections are clean and I am aware of the oil distributor problems as well of the one with the knock sensor but those parts are new clean and working fine wile is cold.
I believe is something related to a temperature problem or sensor.

But I don’t know what else it could be. 

I can afford to take it to the mechanic at this point because I spend the money in all this new parts. 
Can anyone please help me out I'm out of hope, very frustrated and desperate for HELP!
Thank you in advance, Luis.
:balls:


----------



## mensagero4u (Dec 8, 2009)

*1994 Altima GXE Code 43 temperature problem*



mensagero4u said:


> I have a Nissan Altima 1994 GXE 2.4 liter Automatic and I'm having some problems with my car. The problem is that the something is messed up and I don't know what it is. I install new distributor, new Knock sensor, new Throttle position sensor, new spark plugs and new ECU.
> Here is the problem; the car runs perfect in the morning wile is cold.
> After reaching normal temperature I park the car for five minutes and that’s when the problem starts.
> The car runs fine after getting on 2nd gear but ones you get to full stop the car runs like trash.
> ...


Ok, I went out tonight to confirm that the car is working fine wile is cold and that’s exactly what it happen.
Car is working excellent in cold condition but when reach normal temperature start giving me the mysterious problems.
Any help? Please.
:waving:


----------



## mensagero4u (Dec 8, 2009)

Ok I just found something, one of my coolant or temperature sensors are bad and is the one at the top the red one with two pins.
That one is the one signal the ECU and at the same time turns on and off the radiator fan the other one is for the instrument panel.
I notice my car was getting hot but not blowing fans; I took the plug out and start working.
I my say the code 43 for now is there, after I’ll replace the sensor I will reset the ECU and see what happen.
I will replaced and keep you update about what’s going on.


----------



## heelfan92 (Sep 16, 2007)

hopefully that will fix it, but if it doesn't good luck. My dads prelude has had this problem for at least a year and we've changed every sensor on it, and its no better. but this isnt a honda forum so i guess ill shut up, lol.


----------



## mensagero4u (Dec 8, 2009)

I fix it replacing the tranmission selenoid and the dropping resistor, now is perfect.
the TPS only have one position and should be check it with a meter open and closed position.:idhitit:


----------



## slym34 (Aug 27, 2009)

mensagero4u said:


> I fix it replacing the tranmission selenoid and the dropping resistor, now is perfect.
> the TPS only have one position and should be check it with a meter open and closed position.:idhitit:


Can you tell me where dropping resistor is exactly? I'm having the same issue, but haven't found it's location just yet. I hear it's near filter?


----------

