# 92 stanza, runs fine... don't turn left?



## scafidipro (Jan 26, 2005)

My girl friend has a 92 Stanza. It has about 172,000k on it and still runs great!!! I rebuilt the top end after bending all the valves and after that it ran great... Recently i have noticed a strange problem that keeps getting worse and worse. Everytime i turn left the car jumps erratically. It feels like the fuel is cutting off or i'm missing a few pistons. If i turn right its fine... Only if i'm turning left do i have this problem. I have never encountered a problem like this so I am stumped. Any help would be great because this is getting really annoying. Thanks in advance!!!


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## scafidipro (Jan 26, 2005)

Okay, so last night took a left turn with the gas pedal about half-way to the floor. For the apex of the turn it seemed like the fuel was completely shut off. When i started to straiten out the wheel it finally fired and started running again. What the hell could cause this???!!!


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## scafidipro (Jan 26, 2005)

scafidipro said:


> Okay, so last night took a left turn with the gas pedal about half-way to the floor. For the apex of the turn it seemed like the fuel was completely shut off. When i started to straiten out the wheel it finally fired and started running again. What the hell could cause this???!!!


okay.. well thanks for all the replies everyone... this sucks...


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## KA24Tech (Feb 2, 2004)

Sorry that I didn't get to you sooner...

Check the fuel pressure and the fuel pressure regulator.
Check the harness under the hood by pulling on it in different locations while it is running. There may be a harness issue that when you turn the harness is stressed.
Access the ECU after disconnecting the battery, then pull the connector off the ECU and spray the clean both sides of the connection with electrical contact cleaner. Replace the connection, the battery terminal and test drive.
This should give you a few things to check for now. Let me know what you find or if you need more to go on.

Troy


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## scafidipro (Jan 26, 2005)

KA24Tech said:


> Sorry that I didn't get to you sooner...
> 
> Check the fuel pressure and the fuel pressure regulator.
> Check the harness under the hood by pulling on it in different locations while it is running. There may be a harness issue that when you turn the harness is stressed.
> ...


So far i checked the cap and rotor and found a broken gasket on the destributor but everything seemed clean and is firing okay. I checked to make sure all the injectors are firing by disconecting one at a time and they seem to be working fine. Checked the air filter, plugs, cap & rotor, intake manifold vaccum, and did a compression check. everything was fine except for the plugs so i replaced those. replaced the fuel filter... i don't have a fuel pressure tester so i don't think i can check that.


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## scafidipro (Jan 26, 2005)

*Dude, where's your computer? Dude...*

Where is the computer!!!??? I pulled up the carpet on passenger and driver sides and its not there??? I started taking off interior panels and i'm still not finding it!!! The only thing i found was this stupid little box on the driver side behind the panel next to the clutch pedal, but there is no button or lights for self diagnostics... I'm going crazy!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Also i bought a mutli-meter... i finally figured out how to turn it on... what do i do now...


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## KA24Tech (Feb 2, 2004)

You can rent the pressure tester at certain auto parts stores but you might try unplugging the fuel pressure regulator and capping that off, then test driving it to see if it makes any difference. It doesn't guarantee the regulator is good but it can sometimes lessen the symptom enough to suggest that the regulator has an issue.
Also try manipulating the harness as I previously suggested. 
Diagnosing this is one of the most frustrating problems but these things are what usually causes the problem. Let me know what you find.

Troy


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## scafidipro (Jan 26, 2005)

KA24Tech said:


> You can rent the pressure tester at certain auto parts stores but you might try unplugging the fuel pressure regulator and capping that off, then test driving it to see if it makes any difference. It doesn't guarantee the regulator is good but it can sometimes lessen the symptom enough to suggest that the regulator has an issue.
> Also try manipulating the harness as I previously suggested.
> Diagnosing this is one of the most frustrating problems but these things are what usually causes the problem. Let me know what you find.
> 
> Troy


Thank you, thank you, thank you. I will try this tomorrow Do you know where the ECU is? I can't find it anywhere... The haynes manual i have sucks... It doesn't say where it's located.


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## KA24Tech (Feb 2, 2004)

The ECU is located behind the lower front cover of the center console.

Troy


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## scafidipro (Jan 26, 2005)

KA24Tech said:


> The ECU is located behind the lower front cover of the center console.
> 
> Troy


Okay, i found the ecu and ran a self diagnostic check. It flashed code 55 which means everything is fine. I didn't have time to check the connections on the other side yet. i also tried un-hooking the fuel pressure regulator vaccum hose and capping that off. Is that what you meant? That is what my book said to do i think. Or did you mean taking off the fuel return tube and capping that off? Anyway it didn't make a difference. I noticed that the fuse box next to the battery is very loose but i jiggled it and nothing really happened so i doubt that is the culprit... I'm going to buy a fuel pressure tester tomorrow and try to check that. if it does end up having low fuel pressure what does that mean i should replace? How can i make sure, for certain, that it is the pump or the pressure regulator?


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## KA24Tech (Feb 2, 2004)

If the fuel pressure is low try to isolate it by pulling the vacuum line to the fuel pressure regulator if it goes up then the regulator is most likely bad. If no change then the fuel pump or the regulator is possibly bad. Next to isolate this problem, pinch the fuel return line. If the pressure goes up then the regulator is bad. If it stays the same or just slightly increases then the fuel pump is bad. The next test would be to check the fuel pressure lose when the pump is no longer on, with the pressure gauge still inline before the fuel rail turn off the car and observe the pressure gauge and monitor occasionally for at least an hour. The pressure should bleed off very little otherwise the system has another problem. If you have a vacuum pump check the pressure regultor diaphram by applying a vacuum to it as the vacuum increses the fuel pressure should decrease as the car is running.

Try pulling the harness connector at the ECU to inspect it and clean it also. This is where Stanzas will intermitently have a problem.

Troy


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## ftovar (Dec 2, 2004)

It seems to me that before doing a great deal of painful -and potentially damaging- testing around the engine one must rethink what's happening: power cuts off when *steering* in one direction.

If my memory does not fail me and I'm not imagining things, I think I remember somebody asking the same question to the Car Talk guys in NPR. I believe that they suggested a loose/broken wire near or in the starting switch in the steering column. Check and search their website.

Just an idea that I hope would help.


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## scafidipro (Jan 26, 2005)

KA24Tech said:


> Try pulling the harness connector at the ECU to inspect it and clean it also. This is where Stanzas will intermitently have a problem.
> 
> Troy


I pulled off the Connector and it was perfectly clean and installed very firmly to the ECU. was a little dusty on the outside so i just dusted it off and re-installed it. Test drove and still having the same problem. I don't have a vacuum tester or a fuel pressure tester so i can't really check that stuff. I put my finger over the vacuum line from the fuel pressure regulator and it seems to be creating enough suction to function but that's just an estimate. I think i'm just going to take it to a shop up the street. They said they can do a "scope & scan," whatever that means, for $45 and tell me whats wrong.
I am almost positive it is the fuel pump but at $210 for a new one from Nissan i don't want to just start replacing parts i'm not sure about.


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## scafidipro (Jan 26, 2005)

ftovar said:


> It seems to me that before doing a great deal of painful -and potentially damaging- testing around the engine one must rethink what's happening: power cuts off when *steering* in one direction.
> 
> If my memory does not fail me and I'm not imagining things, I think I remember somebody asking the same question to the Car Talk guys in NPR. I believe that they suggested a loose/broken wire near or in the starting switch in the steering column. Check and search their website.
> 
> Just an idea that I hope would help.


I doubt it is an electrical problem because it died once while i was working on it just idling. It also doesn't stall every single time i turn left. It is more of an intermittent problem, although now it is really bad and hesitates almost all the time even while driving strait...


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## scafidipro (Jan 26, 2005)

Finally got it back after being in the shop for 5 days... Turns out it was the fuel pump relay. I guess for some reason when the car was turning the fuel pump was losing voltage due to the relay being kind of messed up. It is really weird though because i tried jiggling all of the relays while it was idling and it didn't do anything. I guess they were able to have one mechanic drive it around the shop while the other sat in the back to test the voltage to the fuel pump. And they traced the voltage drop back to the relay... Anyway, thanks for all the help!


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