2000 Nissan Maxima GE 3.0L #1 injector dumping fuel (FIXED)

Hello Scanner Danner,

I had recently changed the gaskets on the valve covers and plenum. I accidentally pulled out the power wire to the #1 injector but did not know this until I started the car up, ran it for 10-15 minutes, then it shut off. I blew the injector fuse, put a knew one in and immediately blew it again. I had taken the plenum back off to find the ground and there it was, the power wire came out and was short circuiting.

I had fixed that, put it all back together, and started the car back up. It ran but now I had white smoke and raw fuel spewing out of the exhaust. I hooked up my OBD2 reader to find the #1 cylinder was misfiring. I checked the injector harness with a noid light, had a solid light show a ground somewhere as there was no pulse from the computer to that injector but the other 5 had a computer (ECM) pulse . The harness was inspected all the way up to the computer and was fine. I next checked the IAC valve because the ground for the injectors connects to the IAC and that tested fine. I tested all of the injector circuits and wiring with a ground light and still #1 injector had a ground somewhere. I swapped injectors from the #1 to the #2 and still had the same problem.

Next I swapped ECMs from the same car at a junk yard. I had to get the chip key and immobilizer programmed to work. I started up the car and had the same problem with raw fuel dumping in the exhaust.

With the plenum off and fuel pump fuse out, I checked all the injector harness from this new ECM with a noid light and all get a pulse from the computer. I then put a stethescope to each injector and listened for operation (opening and closing) and every injector operated. The original ECM #1 injector circuit seems to be short circuited, but not this other one.

I called 3 different dealers about reprogramming/flashing the computer and they could not give me an answer in surety.

My question is, does this year make and model require a reprogram or flash from the dealer or other software? The only other thing I could think of is an injector sticking open, but is doubtful.

I would appreciate an input on this one.

Andrzej

Instead of a Noid light use a tungsten test light --- 0.4 to 1.5 watt should be okay if that flashes on the problem injector the same as the others all should be okay with the wiring and control so change the injector. This is the best you could do without either doing an injector balance test or using an oscilloscope.

What is a tungsten test light? Can you send a link or picture where I can find one?

I used a ground detecting test light on the injector circuits and found the ground to the #1 injector circuit with the original ECM. The new ECM off the other car sends a pulse to all the injectors and I had listened to all the injectors operate/click with the new ECM.

I doubt it is a partially open injector but you never know.

I think the ECM may need programming/flash.

If you swap ECMs do you have to get it reprogrammed/flashed to operate properly in the other car, even if they are the exact same cars? The dealers could not answer this question.

And I had already tested AND physically examined the #1 injector harness up to the ECM as explained in my original post.

I believe Andy is speaking of a non LED test light.
So that I correctly understand, You possibly shorted out the original ECM and swapped them. Before you swapped them, the #1 injector didn't operate, but since you changed the ECM, you are getting raw fuel from the tailpipe, and the #1 injector is firing. All wiring to the ECM looks good. Is the #1 plug getting fire?

Hey Brewfiner! Have you had the chance to look at codes or scan data since the new ECM was installed? Mostly wondering if the computer picked up on a misfire again, and if the fuel trims reflect an extreme rich condition. Speaking of, does the engine still seem like it has a single cylinder misfire?

As far as reprogramming, I've only installed ECM's on two Nissan/Infiniti models, and neither one required any sort of reprogramming. Just made sure the ECM part number matched the YMM, and relearned the anti-theft system.

An outside chance I can think of is you have excessive fuel pressure from a failed regulator or a pinched return line. Unfortunately, both would require a fuel pressure gauge to diagnose beyond a visual inspection. If you wanted to be 100% about an injector issue, you could remove the injectors and rails from the intake and pressurize the fuel system. A leaking injector will be evident.

Hi Dave,

The #1 plug as far as I know is firing. The spark system is direct coil-to-plug set-up.

Hello Tyler,

Yeah that is what I figured about whether reprogramming/flashing or not. The numbers matched for the ECMs, had the immobilizer and chip programmed to start the car, and still had raw gas dumping from the injector(s).

I am going to pressure test each injector and see what I get. After that....the mystery continues I guess lol.

Thanks for the input so far guys.

Well, fixed the fuel leak problem, now have a high idle problem with this new ECM. It is blowing white smoke out of the exhaust but not raw gas anymore. It seems like coolant. I am wondering if I am having IAC issues.

It revs up to 3,000 to 3,500 rpms and stays there at idle.

How long have you let it run? If you had and injector stuck open, fuel flowing out the exhaust, there may STILL be fuel puddled in the exhaust system. It could take some time to boil/burn off. What does the WHITE SMOKE smell like?

Brewfiner wrote: Well, fixed the fuel leak problem, now have a high idle problem with this new ECM. It is blowing white smoke out of the exhaust but not raw gas anymore. It seems like coolant. I am wondering if I am having IAC issues.

It revs up to 3,000 to 3,500 rpms and stays there at idle.

If you disconnect the IAC, does the engine speed settle down to something reasonable?

It might be easier to use a pressure tester on the radiator and pull the intake boot off the throttle body. Or, remove the IAC motor from the coolant block and see if coolant drips out.

Hello Pole71,

It smelled like a mixture with maybe some left over fuel. Fixed the problem, our friend who helped out installed the cruise control throttles too tight! lol

The car runs great with this ECM from the junk yard.

Thank you all again for your inputs.

Tyler,

I was thinking about that, when I went over to the IAC area while the car ran, I felt that the cruise control cable was a little tight, rotated it and the rpms went up and down. So I corrected the cable, the car purrs like a kitten and runs great!

Thank you all again for your inputs. I will look forward to passing the help forward here.

(FIXED)