About to give up

[Jessyj]

So,i've had my pathfinder for over a year now and still can't solve it's problem ( see older topics) i've change every sensor including ECU checked all wires from sensors to ecu , and car still smokes black (getting to much gas).

 

So if i'm about to sell it parts seening that this problem can't be solved.

[5523Pathfinder]

Im not gonna lie, Im not going to try and findy your old posts. What exactly does your rig do? Happens all the time? Hot? Cold? What all have you changed? ECU codes? No reason to give up if you have gone through all the proper steps. More info you provide, the more we can help.

[Jessyj]

Im not gonna lie, Im not going to try and findy your old posts. What exactly does your rig do? Happens all the time? Hot? Cold? What all have you changed? ECU codes? No reason to give up if you have gone through all the proper steps. More info you provide, the more we can help.

 

 

it's giving me temp sensor and maf sensor .really i think i've tried everything and replace everthing

[Jessyj]

I've changed injector seats,oxygen sensor, maf sensor, ecu, tps sensor, changed mechanics twice

[5523Pathfinder]

Ok. So than I am to assume you relaced both the temp sensor(for the ECM, yellow end), and the Mass air flow meter with new units, correct? If you are burning too much fuel, your computer thinks you are running lean, hence the fuel dump. There is known issues with the O2 sensor itself, as well as water getting into the connector up on the right fender(the sensor harness runs over the top of the trans left to right, then up to the inner fender, behind the battery). It is possible the O2 is not thowing a code. I would pull it out and inspect to make sure nothing is obvious. You may also have a vaccum leak somewhere, causing the rich condition. Look around for anything loose or disconnected. You can even spray around the engine with some carb cleaner or brake clean to check for leaks. If it obvious, you probably can hear it hissing. When you checked the codes, what code(s) numbers were flashed?

 

Oh, I will add, have you double checked the basics? Is the Engine timed properly? New spark plugs? Cap? Rotor? Oil level correct? Runs, well, idles smooth? No other major repairs before this happened?

Edited January 20, 2011 by 5523Pathfinder

[Alkorahil]

adding to what 5523Pathfinder posted:

 

I too have seen many O2 sensors that do not throw a code but are still bad.

The ECU only registers an error is the voltage is less or greater than the specified operating peramiters. IIRC 0.5V is nominal on these O2 sensors with a +/- 0.2v varience. As the engine/exhaust run the voltage output to the ECU will fluxutate between .3V and .7V. What I have seen several times is the O2 sensor is actually bad and stuck inputting to the ECU a constant say.... 0.5V. The ECU will not register this as an error since the input is within norm, however the ECU is not making any adjustments to the mix either so it will run poor.

 

 

 

If you are having MAF problems Nissan had a service bulletin to help correct this problem. Try adding the MAF ground sub harness Part Number: 24079-40F00. Nissan List is : $30.88

This jumper harness gives more ground to the MAF to help with the MAF wiring harness problems the VG30 engines are notorious for. Several people on here including myself have done this fix and had no problems since.

[Channel595]

are you sure it truly is gas smoke? did you have an exhaust analyzer tell you its rich? some times blow by looks the same

[Kingman]

Blow-by is blue, rich gas is black.