About to push my path of a cliff

[Jessyj]

I have a 95 Nissan terrano 4x4 v6

Been having problems since the day bought it, right now the pathy smokes black and hesitates when reaching 2500rpm. When in park it rev ok but a lot of black smoke and back fire throw exhaust. We check all sensor wiring to see if there no shortage and also check to see if there reaching the ECU. Checked spark plugs wire for spark( everything seems ok) Check timing( also ok) Check if maybe my timing belt jump a tooth(also Ok)

List of more things I have done so far,

1. Took off Catalytic converter(thought it might be clogged up)

2. Change fuel filter

3. New knock sensor

4. New temp sensor

5. Cleaned injector and replaced seats

6. Bought used maf sensor and replaced

7. Replaced O2 with universal replacement

 

When we replaced knock sensor the ECU wasn’t giving this code anymore, now it’s giving me Maf Sensor, I replaced the maf sensor but the car is still running the same

 

 

I’m open for any suggestion that I haven’t tried all ready

 

Thanks

[edicer2]

you should try doing a compression test. also maybe different oil, injector cleaner, seafoam. Idk stuff to try that are cheap

[nige]

there is a vacuum line for the fuel pressure regulator near the #6 plug. See if it's cracked, plugged or it got knocked off the fitting.

 

black smoke is usually caused by too much fuel, so keep looking for problems in the fuel system

[Jessyj]

you should try doing a compression test. also maybe different oil, injector cleaner, seafoam. Idk stuff to try that are cheap

 

 

Ok, but we also checked if the injectors a spraying ok and not leaking, (they spraying ok)

 

 

I read somewhere in here about re-learning the ECU, how do i go about doning that?

[Jessyj]

there is a vacuum line for the fuel pressure regulator near the #6 plug. See if it's cracked, plugged or it got knocked off the fitting.

 

black smoke is usually caused by too much fuel, so keep looking for problems in the fuel system

 

 

We change the vacuum line and also replaced the fuel pressure regulator

[RJSquirrel]

Recheck your distributor and verify your ignition timing. It sounds like its isn't advancing properly. Use a timing light to see if it advances as you change RPMs. Re-verify that each plug wire is good. Is the distributor cap and rotor in good condition. Are the spark plugs clean and gapped properly? A dirty one will identify which cylinder is misfiring. Check fuel pressure. The pump may not be able to keep up as the RPMs increase. Rust in the fuel rail may be starving a cylinder as the RPMs climb.

 

Good luck.

[Simon]

It may be the ground wire on the harness for the MAF if it's throwing a code. It's not uncommon for folks to have to run new grounds off the plug, as the one in the harness stops working.

[Jessyj]

It may be the ground wire on the harness for the MAF if it's throwing a code. It's not uncommon for folks to have to run new grounds off the plug, as the one in the harness stops working.

 

 

 

I will try that, and the other suggestions

 

on the maf sensor there are A B C A= white wire B=Black C=Black/white

 

C= ground if not mistaking , I should rewire that right?

[gr8xr7]

Had this problem and found out it was the return line to the gas tank, hole in it. Very easy and cheap fix. Good luck.

[Chriskaw440]

Had this problem and found out it was the return line to the gas tank, hole in it. Very easy and cheap fix. Good luck.

 

black smoke can also be caused by faulty coolant temp sensor as I had experienced in the past. Engine thinks it is running "too cool" so it dumps more fuel into the cylinders..thus causing black smoke. My temp sensor just had a lose connection caused by the plastic housing being so brittle from age and broken up. Once it was fixed, no more black smoke.