1994 Nissan Maxima 6 cyl GXE

Ok I followed the various instructions on how to read error codes thru the ecu and Im getting an error code 51 - Fuel injector circuit open (California models only) ..... How do i correct this?

Im a newbie so pictures are worth a thousand words to me if possible......

 

does the car run poorly/rough/stumbly? the 51 usually means you have a dead injector, tho sometimes it can be wiring/corrosion on the electrical contacts. check all your fuel injector plugs for green corrosion, and clean that up. if that doesn't fix the code and get the car smooth again, do a power balance test by pulling off one spark plug wire at a time, searching for whichever cylinder does NOT affect the car's idle. that cylinder is the cylinder whose injector needs replacement. (protip: turn the ECU screw all the way to the right to shut the iacv off, that will help make the dead cylinder more apparent since the idle will not automatically compensate. turn it back to the left before driving the car tho.

 

Ok thanks for the response ..... When the check engine light is on, it idles rough, sometimes with a noticable vibration and sometimes with a slight vibration .... A few times it will stall when i back up but will start right back up .... When i drive sometimes there is a slight hesititation when i press the accellerator but it is mostly when im stopped at a stop sign or light when it seems like it might stall but doesnt..... The check engine light and vibration used to go away when i used b12 or fuel injector or that heet added to the gas ... like i said used to ....

A lil bit of history is that I had a hole in the radiator hose that led to the engine so I dont know where it squirted water and antifreeze on but thats been fixed along with a new radiator .....

Im not sure about what the fuel injectors look like ... so a picture to me is worth a thousand words .... but on the spark plug wires do I disconnect them from the spark plug or the distributor when im testing them????

 

you would dissconnect them from the sparkplug because you still need the end connected tot he distributer to throw the spark through the wire....but i believe your dealing with a fouling injector or 2.....

 

It's 100% a dead injector, now you need to figure out which one..

 

huh? you disconnect them from the spark plug so you don't get shocked.. not the reason you said. you can disconnect the wires from the distributor, but you'll probably get zapped pretty good if you do.

 

Oops must have been thinking about checking plug wires and not injectors

 

And I agree 100% with him

 

History - The ECU returned an error code 51 so it was suggested that I check each spark plug wire to determine where the bad injector was located .... with the ECU screw turned all the way to the right.

So I went out and started the car and when I turned the ECU all the way to the right the car stalled and had trouble starting it back at first but it would start but unless I was pumping the accellerator it would stall before I got out of the car (no helper) ...... when i turned the ECU back to the left the car started but more sluggish .. but whenever I turned the ECU to the right it would stall as soon as I turned it to the right ...

SO .... I didnt even attempt to adjust the idle or check wires while the ECU was turned back to the left as I figured the 1st spark plug/injector is bad?


Here is a video of the car motor idling with ECU turned back to

http://www.geocities.com/bigdmusicma...otoridling.wmv


Here is a video of the exhaust while the car motor is idling with ECU turned back to left (Its not really really loud in person as it sounds on video)

http://www.geocities.com/bigdmusicma...austidling.wmv

Whats my next step????

 

Im asking ..... do I still need to try and check the spark plug wires one by one with the ECU turned to the right or do I need a mechanic????

Is it stalling because the first plug/injector is bad???

 

Where do you live fotoman? We might have a 3rd gen member close to you with some experience with diagnosis/ injector replacement.

If no one is close to your location,i suggest you take the bad injector information that you already have and take your car to a known trusted mechanic for repair.

 

Im in Dallas, Texas

 

OK keep in mind im new to this .... but while checking the injectors for corrosion, etc ..... around the spark plug area of #1 injector I saw a loose tube I hadnt ever noticed before ..maybe it was knocked loose during the spark plug and spark plug wire installation or while i was adding oil or when they replaced my radiator hose? Should i reconnect the tube and what does it do?


This is a pic of the loose tube .....




This is a pic of where the tube is coming from what does this do.....

 

it's the "water cock" valve. when your hot/cold slider is on full-cold, it blocks coolant flow through the heater core. replace that bit of cracked hose on the manifold and plug it in

 

That's the vacuum line to your heater control valve, plug it back into the larger rubber part right by that hose..

and wrap some electrical tape around that rubber intake part it plugs into, it's cracked pretty bad(read: vacuum leak=crappy running)

 

Ok I reconnected the tube and taped the cracked part up ......

When I started the car it idled consistently around 750 rpms or just around 1000 and the vibration was barely noticeable but I cold still hear a softer miss than before from the exhaust ..... Whenever i stepped on the accell the check engine light went on and stayed on after i drove it around the corner and it still has a slight hestitation at first sometimes but the idle was not as rough as before and i can hear the miss as I drive.... Checked the ecu and still have the error #51 ...... So I turned the ecu **** all the way to the right and it did not stall but there was a noticable ruffness in the idle ..... I suspected that #1 and/or #3 were the bad spark/injector but they all sound like they are clicking .. it was getting dark and i forgot what kind of sound I was listening for .... so want to know what yall think????

 

wat happens wen u disconnect the MAF sensor harness? its the black one between ur intake...

 

Well ... if your listening/watching the videos I posted earlier that was before I knew/discovered that the vacuum line was not connected .......

I dont know what the MAF sensor is or what it does ... what would disconnecting it do??

 

Second year automotive tech huh?, he has a freaking code 51= a dead injector. this is the only reason the car is sputtering.Stop trying to confuse the issue with unfounded stupid guesses..

 

I have this exactly same problem, code 51, car stumbles, rough idle, sputters, etc.

It is indeed a dead injector, had this problem like for two months now, but unfortunately can't afford to pay mechanic and I don't have the experience to do it myself.

However my injectors (All of them) had a lot of (green) corrosion and even I clean them the problem is still there, so I know one of my injectors is dead, but I did not knew that I have to turn the ECU all the way to the right to unplug every spark plug, I though i was suggested to disconnect every injector.

Well I just want to confirm what everybody already told you, Dead Injector.

 

If it wasnt for me reading thru past threads I wouldnt have stumbled across the one that let me know that the car had an ecu and then how to operate/read it ......

I hadnt had the opp to check each spark plug/injector one by one as i have been getting home after dark.

However I dont recall seeing any green corrosion around an injector ..but now that i think of it I may not have checked all of them only the ones that were clearly visible .....


What should I ask for if i get one at a pick your part place and whats the price range once i figure out which one is bad?

 

i would never buy a used injector much less one from a pull your part j/y buy a new one because they will more than likely break again and force u to go through all of this to replace em again

http://www.internetautosupply.com/ca...0eedeedd7fc7f2

this site run by a org member internetautomar

 

Well ... from what i could determine after i turned the ecu all the way to the right ...... when I disconnected spark plug wire #4 there was no change in the idle but it stalled when i disconnected #2 and there were subtle and ruffer changes when I disconnected #1,3,5 and 6. But it seemed like i could still hear clicking when I disconnected # 4.

I didnt notice any corrosion on the injectors i could see ..do yall think i could have a bad spark plug on #4 as it seemed like all the injectors were clicking when i pulled the spark plug wire?

If its an injector I will go ahead and buy a new one .... and whats the difference between a green marking and a yellow marking... WHY ARE THEY SO EXPENSIVE?

 

well, you probably heard the other 5 injectors clicking when #4 was disconnected... so #4 is still likely your code-thrower.

 

I guess what would be helpful for those driving with a bad injector(s) is to know what precautions other than not driving at all should be used while driving before the bad injector is replaced. I use my car to drive very short distances - 10 to 20 miles with rest stops in between trips and rarely take the highway, but I know some people drive longer and faster, what do we need to do not to make the problem worse, like does using fuel injector cleaner helps, etc....

 

most fuel injector cleaners u pour in the tank are crap get a nitrogen flush ive had three and each time the engine feels brand new (never had a bad injector either)

 

i've always heard good stuff about BG44k tho. i'm usually not a fan of the typical STP or Gumout ones (often wonder if they do more harm than good, somehow) but there are good/effective cleaners out there. just usually they cost more too.

 

ive never heard of bg44k but it looks quality ive heard this stuff is pretty good too: http://www.wynnsusa.com/Fuel.aspx

but theres a huge difference in just pouring some cleaner in your tank and having a pressurized flush no matter what chemical ur using

 

My god people, just replace the injector in question.....

 

I noticed a lot of people on the forum have a problem with fuel injectors or similar and I totally intend on replacing the bad injector at some point but it appears to be an expensive repair at the moment, so in the meanwhile i just wanted to see what i could do until then, I have never heard of the BG 44K, not sure if its available at Auto Zone or OReillys as I was just looking for the fuel injector cleaners that were on sale and that retails for around $20 bucks, i will give it a try or maybe one of the higher end Lucas brands in the meanwhile ... when I first started getting the sputtering I was told I prob had a case of bad gas and the fuel injector cleaners did smooth the vibration but the miss was still there ... but as i stated above i will still have the fuel injector replacement done as soon as I can afford to.

 

Where can you get a nitrogen cleaning?