maf sensor wire is jet black..
05-05-2017, 01:11 AM
#1
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Join Date: Feb 2016
Posts: 9
maf sensor wire is jet black..
Hi all. I went to go clean my MAF as it seems like from 4500rpm and beyond, the car's horsepower goes flat.. and in general, the car drives more like a 4 cylinder.. and i've got no check engine codes going on.
I went to go hit the little MAF sensor wire with CRC MAF cleaner, and the sensor wire was jet black. Despite a few direct hits with the MAF cleaner, it remained black.
I previously owned a 1996 Nissan 200SX SE-R and had this same problem, and the sensor wire was blackish. The MAF cleaner took the gunk right off, revealing a shiny grayish metallic surface, and the car had a massive power gain.
Is permanently black a normal color for the sensor wire? i do believe i have my original Nissan MAF sensor on there.
I went to go hit the little MAF sensor wire with CRC MAF cleaner, and the sensor wire was jet black. Despite a few direct hits with the MAF cleaner, it remained black.
I previously owned a 1996 Nissan 200SX SE-R and had this same problem, and the sensor wire was blackish. The MAF cleaner took the gunk right off, revealing a shiny grayish metallic surface, and the car had a massive power gain.
Is permanently black a normal color for the sensor wire? i do believe i have my original Nissan MAF sensor on there.
05-05-2017, 10:42 AM
#3
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Join Date: Feb 2016
Posts: 9
Changed the fuel filter a few months ago. Car fires up super strong from -20F to 120F even thought the battery is on it's last legs AND undersized. 220,000 miles on it now.
The car is kinda laggy up to about 3000rpm, it peaks around 4000rpm, and barely makes any additional power beyond that.
Up to about 2500rpm, if the throttle is pressed down significantly ( like i'm lugging it up a slight grade ), there is a pulsing in the engine. The coils and injectors are very suspect for this. This is not really present above 2500rpm but the more you lug it and the closer the RPM is to idle, the more you can feel the vibration.
I have 2.25" exhaust and a short ram intake and a good cat, so airflow isn't a problem. I'm sure some of the lagginess is from all that air, but i should have way more power up top. But it's flat.
The car is kinda laggy up to about 3000rpm, it peaks around 4000rpm, and barely makes any additional power beyond that.
Up to about 2500rpm, if the throttle is pressed down significantly ( like i'm lugging it up a slight grade ), there is a pulsing in the engine. The coils and injectors are very suspect for this. This is not really present above 2500rpm but the more you lug it and the closer the RPM is to idle, the more you can feel the vibration.
I have 2.25" exhaust and a short ram intake and a good cat, so airflow isn't a problem. I'm sure some of the lagginess is from all that air, but i should have way more power up top. But it's flat.
05-05-2017, 05:01 PM
#5
Senior Member
Join Date: May 2012
Location: Long Island
Posts: 1,564
For it to be coil packs the way you describe, it would have to be several at the same time. And if that were the case, it would also struggle at idle. Especially with the A/C on.
When was the last time you inspected the plugs? If you can't remember, maybe they've eroded to this point. They'd have to be really bad.
JvG, I think is pointing you in the right direction. Fuel Pressure or Fuel Injectors or maybe the TPS is shot and the ECU is sending the wrong information to the Injectors. So could the MAF.
Watch.... It's the tire pressure.
(J/K) LOL
Hope this helps!
When was the last time you inspected the plugs? If you can't remember, maybe they've eroded to this point. They'd have to be really bad.
JvG, I think is pointing you in the right direction. Fuel Pressure or Fuel Injectors or maybe the TPS is shot and the ECU is sending the wrong information to the Injectors. So could the MAF.
Watch.... It's the tire pressure.
(J/K) LOLHope this helps!
05-06-2017, 12:09 AM
#6
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Thread Starter
Join Date: Feb 2016
Posts: 9
Not to be ungrateful for your replies, but.. I've already been on a wild goose chase for over a year with this car and it's been totally frustrating. Let me tell you about what i've done in the last year:
1) spark plugs - no noticeable change. The old plugs were extremely worn but there were no signs of oil, detonation, or any other nasty condition.
2) replaced airbox that was leaking in multiple places with a short ram ( and yes, the intake air temp sensor is hooked up, it wasn't before ) - no change other than a slight shift upwards in the power band. I am a graveyard worker and drive the car at night, mostly highway, so heat soak is NOT the issue.
3) replaced ALL coil packs with a set that was apparently the wrong model for my car, yet the car still had the pulsing and performance was about the same. Put old coil packs on. Pulsing continues.
4) replaced all the exhaust tubing, resonator, and muffler.
5) replaced both front oxygen sensors. Cleared CEL, and actually saw a drop in power. I suspect that there are two different brands of oxygen sensor on the front. Readings in the torque app via a bluetooth OBD2 connector do have differing voltages and patterns. The car used to spin the tires with the CEL on.
6) cleaned MAF. Got a tiny power boost from this which subsided quickly. That is why i suspect the MAF is involved.
7) replaced several leaking vacuum hoses under the hood connected to the intake. No change.
8) had the EGR tube cleaned because there was a code for EGR flow. Replaced EGR solenoid on the motor. Code went away, popped up again, went away again, popped up again.. and now the CEL is not on. I strongly suspect that the EGR tube was not completely cleaned and plan to look into that and straight up replace the EGR valve.
9) PCV valve was replaced. No change.
Let's talk fuel since 2 of you brought that up.
I don't wait for the car to build up pressure before starting it, and it fires up great in all temps.
When the gas tank is down to 1/8th or below, i DO get sluggish starting and the performance starts to suffer the more i get close to having the gas tank light come on.
If i overfill the tank just a hair, the car will idle at 1500-2000rpm for a few minutes. I do not know if this is normal or not.
When i shut the car off, there is a loud mechanical pump sound coming from the area where the gas cap is located. It has been getting louder. It will run for a few minutes after shutting the car off. I believe this is where the other part of the evap system is located.
Fuel economy is as expected, but has been dropping. I hypermile my car and average 24-34mpg. My 20 mile highway record is 36mpg average, but it's been a struggle to even get 32mpg lately
So as you can tell, this car is a bit of a basket case and has had a lot of work. I still suspect the MAF for the severe loss of high RPM power. If you guys can't tell me whether the sensor element being jet black is normal or not, i get to head to the junkyard to inspect a few used MAF sensors, but that's hard to do because i work 70 hours a week so i figured i'd ask here instead.
1) spark plugs - no noticeable change. The old plugs were extremely worn but there were no signs of oil, detonation, or any other nasty condition.
2) replaced airbox that was leaking in multiple places with a short ram ( and yes, the intake air temp sensor is hooked up, it wasn't before ) - no change other than a slight shift upwards in the power band. I am a graveyard worker and drive the car at night, mostly highway, so heat soak is NOT the issue.
3) replaced ALL coil packs with a set that was apparently the wrong model for my car, yet the car still had the pulsing and performance was about the same. Put old coil packs on. Pulsing continues.
4) replaced all the exhaust tubing, resonator, and muffler.
5) replaced both front oxygen sensors. Cleared CEL, and actually saw a drop in power. I suspect that there are two different brands of oxygen sensor on the front. Readings in the torque app via a bluetooth OBD2 connector do have differing voltages and patterns. The car used to spin the tires with the CEL on.
6) cleaned MAF. Got a tiny power boost from this which subsided quickly. That is why i suspect the MAF is involved.
7) replaced several leaking vacuum hoses under the hood connected to the intake. No change.
8) had the EGR tube cleaned because there was a code for EGR flow. Replaced EGR solenoid on the motor. Code went away, popped up again, went away again, popped up again.. and now the CEL is not on. I strongly suspect that the EGR tube was not completely cleaned and plan to look into that and straight up replace the EGR valve.
9) PCV valve was replaced. No change.
Let's talk fuel since 2 of you brought that up.
I don't wait for the car to build up pressure before starting it, and it fires up great in all temps.
When the gas tank is down to 1/8th or below, i DO get sluggish starting and the performance starts to suffer the more i get close to having the gas tank light come on.
If i overfill the tank just a hair, the car will idle at 1500-2000rpm for a few minutes. I do not know if this is normal or not.
When i shut the car off, there is a loud mechanical pump sound coming from the area where the gas cap is located. It has been getting louder. It will run for a few minutes after shutting the car off. I believe this is where the other part of the evap system is located.
Fuel economy is as expected, but has been dropping. I hypermile my car and average 24-34mpg. My 20 mile highway record is 36mpg average, but it's been a struggle to even get 32mpg lately
So as you can tell, this car is a bit of a basket case and has had a lot of work. I still suspect the MAF for the severe loss of high RPM power. If you guys can't tell me whether the sensor element being jet black is normal or not, i get to head to the junkyard to inspect a few used MAF sensors, but that's hard to do because i work 70 hours a week so i figured i'd ask here instead.
05-06-2017, 02:00 AM
#7
Senior Member
Join Date: May 2012
Location: Long Island
Posts: 1,564
With the age and mileage of our cars, it's a good idea to keep another MAF sensor. If you can find one at a JY and it's OK, it will help diagnose issues like this. If you swap it and things are suddenly OK, you've found your problem. Some of the guys here do exactly this. This is the most reliable way to figure out if it's your MAF. And many MAFs die a slow intermittent death.
Now about the TPS, read this and understand that there are many sensors helping the brain gauge how to deliver the gas and air mixture for running properly throughout the Tachometer range. http://easyautodiagnostics.com/nissa...sensor-tests-1
The things that are happening with the tank getting close to empty or topped off are NOT typical. Noise from the filler area is usually fuel pump control module or something with the evap system. The Fuel Pump is in the tank and accessible under the rear seats in the middle. (CS_AR recently started a thread about doing his evap canister and supporting parts around that system. Should be in the top 20 threads in the 4th gen forum.) Read up and see if any is applicable to your situation.
Many times these are quite ambiguous to really figure out with so many different places that can cause the symptoms. Sometimes it's just trial and error that eventually finds it.
Don't give up, when you find the problem and fix it, with all that you've done, she'll run nicely! You're pretty close to finding it.
Now about the TPS, read this and understand that there are many sensors helping the brain gauge how to deliver the gas and air mixture for running properly throughout the Tachometer range. http://easyautodiagnostics.com/nissa...sensor-tests-1
The things that are happening with the tank getting close to empty or topped off are NOT typical. Noise from the filler area is usually fuel pump control module or something with the evap system. The Fuel Pump is in the tank and accessible under the rear seats in the middle. (CS_AR recently started a thread about doing his evap canister and supporting parts around that system. Should be in the top 20 threads in the 4th gen forum.) Read up and see if any is applicable to your situation.
Many times these are quite ambiguous to really figure out with so many different places that can cause the symptoms. Sometimes it's just trial and error that eventually finds it.
Don't give up, when you find the problem and fix it, with all that you've done, she'll run nicely! You're pretty close to finding it.
05-06-2017, 08:24 AM
#9
Newbie - Just Registered
Thread Starter
Join Date: Feb 2016
Posts: 9
In my OBD reader, the TPS readouts seem to go from 0 to 99, in accordance with the pedal. What does a bad TPS look like?
05-07-2017, 03:27 PM
#13
Senior Member
Join Date: Jan 2011
Location: Central AR
Posts: 3,041
TB - Does the one you purchased from Autozone have a green seal?
Check this out..
Autozone Part DL-6010 -$140.99
http://www.autozone.com/engine-manag...266832_0_12219
Advance Auto Part MA142 - $140.99
https://shop.advanceautoparts.com/p/...142/10033334-P
If these are the same parts, a TRT41 discount code at Advance brings the price down to $100.99.
Rock Auto Spectra MA142 - $88.79
https://www.rockauto.com/en/moreinfo...=6284253&jsn=3
::
Check this out..
Autozone Part DL-6010 -$140.99
http://www.autozone.com/engine-manag...266832_0_12219
Advance Auto Part MA142 - $140.99
https://shop.advanceautoparts.com/p/...142/10033334-P
If these are the same parts, a TRT41 discount code at Advance brings the price down to $100.99.
Rock Auto Spectra MA142 - $88.79
https://www.rockauto.com/en/moreinfo...=6284253&jsn=3
::
Last edited by CS_AR; 05-07-2017 at 03:31 PM.
05-08-2017, 10:37 AM
#14
Senior Member
Join Date: Oct 2012
Location: Portland, Oregon
Posts: 2,979
Not to be ungrateful for your replies, but.. I've already been on a wild goose chase for over a year with this car and it's been totally frustrating. Let me tell you about what i've done in the last year:
1) spark plugs - no noticeable change. The old plugs were extremely worn but there were no signs of oil, detonation, or any other nasty condition.
2) replaced airbox that was leaking in multiple places with a short ram ( and yes, the intake air temp sensor is hooked up, it wasn't before ) - no change other than a slight shift upwards in the power band. I am a graveyard worker and drive the car at night, mostly highway, so heat soak is NOT the issue.
3) replaced ALL coil packs with a set that was apparently the wrong model for my car, yet the car still had the pulsing and performance was about the same. Put old coil packs on. Pulsing continues.
4) replaced all the exhaust tubing, resonator, and muffler.
5) replaced both front oxygen sensors. Cleared CEL, and actually saw a drop in power. I suspect that there are two different brands of oxygen sensor on the front. Readings in the torque app via a bluetooth OBD2 connector do have differing voltages and patterns. The car used to spin the tires with the CEL on.
6) cleaned MAF. Got a tiny power boost from this which subsided quickly. That is why i suspect the MAF is involved.
7) replaced several leaking vacuum hoses under the hood connected to the intake. No change.
8) had the EGR tube cleaned because there was a code for EGR flow. Replaced EGR solenoid on the motor. Code went away, popped up again, went away again, popped up again.. and now the CEL is not on. I strongly suspect that the EGR tube was not completely cleaned and plan to look into that and straight up replace the EGR valve.
9) PCV valve was replaced. No change.
Let's talk fuel since 2 of you brought that up.
I don't wait for the car to build up pressure before starting it, and it fires up great in all temps.
When the gas tank is down to 1/8th or below, i DO get sluggish starting and the performance starts to suffer the more i get close to having the gas tank light come on.
If i overfill the tank just a hair, the car will idle at 1500-2000rpm for a few minutes. I do not know if this is normal or not.
When i shut the car off, there is a loud mechanical pump sound coming from the area where the gas cap is located. It has been getting louder. It will run for a few minutes after shutting the car off. I believe this is where the other part of the evap system is located.
Fuel economy is as expected, but has been dropping. I hypermile my car and average 24-34mpg. My 20 mile highway record is 36mpg average, but it's been a struggle to even get 32mpg lately
So as you can tell, this car is a bit of a basket case and has had a lot of work. I still suspect the MAF for the severe loss of high RPM power. If you guys can't tell me whether the sensor element being jet black is normal or not, i get to head to the junkyard to inspect a few used MAF sensors, but that's hard to do because i work 70 hours a week so i figured i'd ask here instead.
1) spark plugs - no noticeable change. The old plugs were extremely worn but there were no signs of oil, detonation, or any other nasty condition.
2) replaced airbox that was leaking in multiple places with a short ram ( and yes, the intake air temp sensor is hooked up, it wasn't before ) - no change other than a slight shift upwards in the power band. I am a graveyard worker and drive the car at night, mostly highway, so heat soak is NOT the issue.
3) replaced ALL coil packs with a set that was apparently the wrong model for my car, yet the car still had the pulsing and performance was about the same. Put old coil packs on. Pulsing continues.
4) replaced all the exhaust tubing, resonator, and muffler.
5) replaced both front oxygen sensors. Cleared CEL, and actually saw a drop in power. I suspect that there are two different brands of oxygen sensor on the front. Readings in the torque app via a bluetooth OBD2 connector do have differing voltages and patterns. The car used to spin the tires with the CEL on.
6) cleaned MAF. Got a tiny power boost from this which subsided quickly. That is why i suspect the MAF is involved.
7) replaced several leaking vacuum hoses under the hood connected to the intake. No change.
8) had the EGR tube cleaned because there was a code for EGR flow. Replaced EGR solenoid on the motor. Code went away, popped up again, went away again, popped up again.. and now the CEL is not on. I strongly suspect that the EGR tube was not completely cleaned and plan to look into that and straight up replace the EGR valve.
9) PCV valve was replaced. No change.
Let's talk fuel since 2 of you brought that up.
I don't wait for the car to build up pressure before starting it, and it fires up great in all temps.
When the gas tank is down to 1/8th or below, i DO get sluggish starting and the performance starts to suffer the more i get close to having the gas tank light come on.
If i overfill the tank just a hair, the car will idle at 1500-2000rpm for a few minutes. I do not know if this is normal or not.
When i shut the car off, there is a loud mechanical pump sound coming from the area where the gas cap is located. It has been getting louder. It will run for a few minutes after shutting the car off. I believe this is where the other part of the evap system is located.
Fuel economy is as expected, but has been dropping. I hypermile my car and average 24-34mpg. My 20 mile highway record is 36mpg average, but it's been a struggle to even get 32mpg lately
So as you can tell, this car is a bit of a basket case and has had a lot of work. I still suspect the MAF for the severe loss of high RPM power. If you guys can't tell me whether the sensor element being jet black is normal or not, i get to head to the junkyard to inspect a few used MAF sensors, but that's hard to do because i work 70 hours a week so i figured i'd ask here instead.
Please consider this as a possibility before you throw yet more money and parts at it.
A fuel starved car will run ok at low rpm, but will bog down at high rpm. Because it can't get enough fuel.
I've had cars with dirty fuel filters, bad fuel pumps etc. The cars acted much like yours.
05-09-2017, 04:22 AM
#15
Senior Member
Join Date: Jan 2011
Location: Central AR
Posts: 3,041
You have tried just about everything except measuring fuel pressure, or perhaps more important, fuel volume at pressure.
Please consider this as a possibility before you throw yet more money and parts at it.
A fuel starved car will run ok at low rpm, but will bog down at high rpm. Because it can't get enough fuel.
I've had cars with dirty fuel filters, bad fuel pumps etc. The cars acted much like yours.
Please consider this as a possibility before you throw yet more money and parts at it.
A fuel starved car will run ok at low rpm, but will bog down at high rpm. Because it can't get enough fuel.
I've had cars with dirty fuel filters, bad fuel pumps etc. The cars acted much like yours.
I use a $19 fuel pressure testing kit that I bought at Harbor Freight (Item#62623) several years ago to rule out pump/regulator issues.
06-13-2017, 11:04 AM
#16
Newbie - Just Registered
Thread Starter
Join Date: Feb 2016
Posts: 9
You have tried just about everything except measurine fuel pressure, or perhaps more important, fuel volume at pressure.
Please consider this as a possibility before you throw yet more money and parts at it.
A fuel starved car will run ok at low rpm, but will bog down at high rpm. Because it can't get enough fuel.
I've had cars with dirty fuel filters, bad fuel pumps etc. The cars acted much like yours.
Please consider this as a possibility before you throw yet more money and parts at it.
A fuel starved car will run ok at low rpm, but will bog down at high rpm. Because it can't get enough fuel.
I've had cars with dirty fuel filters, bad fuel pumps etc. The cars acted much like yours.
I don't know if this rules out a MAF.. but i still haven't had a chance to see if the wire should be jet black or not on a new one..
The EGR needs replacement, so i plan to tackle the fuel injectors using CS_AR's part recommendations this summer.
One thing i noticed is that the EGR check engine code pops on and off. There is a significant difference in power whether it is on or off. I believe my car might be going back and forth between a limp mode.
Yes, there is way too much going on with this car.. i wanted to rule out 1 part first ..
