Hyundai Forums banner

1 - 20 of 50 Posts

·
Registered
Joined
·
18 Posts
Discussion Starter #1
hi.

ive been getting the p0101 fault code on my reader. i have been going through the sensor readings and discovered my MAF reading 9.76g/sec at idle when the engine is warm. idle is at 860rpm. I know this is quite high. the maf is working fine. if it is a leak, would it be pre-Maf or after to get that reading?. thank you in advance.
 

·
Registered
Drives : Nissan NV200 Flies : Rans S6ES
Joined
·
14,610 Posts
First of all, you can't get a vacuum leak on diesel engine because they don't generate any manifold vacuum.
And if there was an intake air leak it wouldn't cause the MAF reading to be high. It would cause it to be low, because the air that is leaking in will be taking up space in the cylinders that would normally be filled with the air that passes through the MAF sensor. So there is less air passing through the sensor, meaning the MAF value on the scan tool will be lower than normal.

If I helped you fix it, why not...

Your support is greatly appreciated
 

·
Registered
Joined
·
6,808 Posts
That engine will pump about 1.5 grams per second at idle. Something is off with your reading.
 

·
Registered
Joined
·
18 Posts
Discussion Starter #4
Thanks for the quick reply guys. i am also getting a p0532 code which is A/C Refrigerant Pressure Sensor Circuit Low Input. would this have any affect to the high maf reading. i have also replaced the maf with the exact type as the original and the readings are still the same. someone suggested doing the ecu reset method. im not sure it would sort ot though.
 

·
Registered
Joined
·
6,808 Posts
Your AC pressure will have zero effect on the MAF. Two different animals. I would try another scan tool. That engine would not run worth a hoot if that number were right.
 

·
Registered
Drives : Nissan NV200 Flies : Rans S6ES
Joined
·
14,610 Posts
That engine will pump about 1.5 grams per second at idle.
LOL...I think someone has mixed up their fuel and air induction figures. It might pump 1.5 grams of fuel per second, but it will be sucking in significantly more air than that. It's not the OP's reading that's off. It's your math, by a significant margin.

i am also getting a p0532 code which is A/C Refrigerant Pressure Sensor Circuit Low Input. would this have any affect to the high maf reading.
No, that wont effect the MAF reading. It just means your AC isn't working because the gas pressure is too low.

SamH79 said:
i have also replaced the maf with the exact type as the original and the readings are still the same.
Your MAF reading didn't look bad to me. Not at idle anyway.
I assume you erased the code after replacing the sensor? Has the same code been logged again since?

MAF range/performance problems are often not caused by a fault with the MAF sensor or the air intake system. They are quite often caused by problems with the EGR valve. It might be worth removing the valve and giving it a good clean. They tend to get gummed up with carbon from the exhaust gas.

If I helped you fix it, why not...

Your support is greatly appreciated
 

·
Registered
Drives : Nissan NV200 Flies : Rans S6ES
Joined
·
14,610 Posts
That engine would not run worth a hoot if that number were right.
Your a hoot. There isn't anything wrong with his MAF number.

If I helped you fix it, why not...

Your support is greatly appreciated
 

·
Registered
Joined
·
6,808 Posts
LOL...I think someone has mixed up their fuel and air induction figures. It might pump 1.5 grams of fuel per second, but it will be sucking in significantly more air than that. It's not the OP's reading that's off. It's your math, by a significant margin.
RoT on an engine is 1 gram air for 1 liter displacement. It's the right math.
 

·
Registered
Joined
·
18 Posts
Discussion Starter #9
LOL...I think someone has mixed up their fuel and air induction figures. It might pump 1.5 grams of fuel per second, but it will be sucking in significantly more air than that. It's not the OP's reading that's off. It's your math, by a significant margin.


No, that wont effect the MAF reading. It just means your AC isn't working because the gas pressure is too low.


Your MAF reading didn't look bad to me. Not at idle anyway.
I assume you erased the code after replacing the sensor? Has the same code been logged again since?

MAF range/performance problems are often not caused by a fault with the MAF sensor or the air intake system. They are quite often caused by problems with the EGR valve. It might be worth removing the valve and giving it a good clean. They tend to get gummed up with carbon from the exhaust gas.

If I helped you fix it, why not...

Your support is greatly appreciated
its
 

·
Registered
Joined
·
18 Posts
Discussion Starter #10
i did delete the codes and they returned as pending. the car was driving rough and felt really heavy
 

·
Registered
Drives : Nissan NV200 Flies : Rans S6ES
Joined
·
14,610 Posts
the car was driving rough and felt really heavy
The engine was running rough? By heavy you mean the engine performance was poor?
Those are another two symptoms we often see when there are EGR problems.

Does your scan tool allow you to view freeze frame data? Freeze frame data is data from some of the engine sensors that are recorded at the moment the trouble code is logged. It will let you see what the engine parameters were when the code was logged.

If I helped you fix it, why not...

Your support is greatly appreciated
 

·
Registered
Joined
·
18 Posts
Discussion Starter #13
The engine was running rough? By heavy you mean the engine performance was poor?
Those are another two symptoms we often see when there are EGR problems.

Does your scan tool allow you to view freeze frame data? Freeze frame data is data from some of the engine sensors that are recorded at the moment the trouble code is logged. It will let you see what the engine parameters were when the code was logged.

If I helped you fix it, why not...

Your support is greatly appreciated
The engine was running rough? By heavy you mean the engine performance was poor?
Those are another two symptoms we often see when there are EGR problems.

Does your scan tool allow you to view freeze frame data? Freeze frame data is data from some of the engine sensors that are recorded at the moment the trouble code is logged. It will let you see what the engine parameters were when the code was logged.

If I helped you fix it, why not...

Your support is greatly appreciated
446497
this was it at the time of the dtc.
 

·
Registered
Joined
·
6,808 Posts
OK, but where does the time factor in? You said 1.5 grams per second.
Prove it. Show us how you calculate mass air flow.
He's viewing the parameter as we use it in the US market. The only way we look at MAF is in g/sec. The calculations are found here but I just use the RoT of 1 g/sec per liter of displacement. Regardless of engine type under normal idling conditions this is very close. A 1L engine is very close to 1g/sec and a 6.5L will be close to 6.5g/sec. Just the way it is.
 

·
Registered
Drives : Nissan NV200 Flies : Rans S6ES
Joined
·
14,610 Posts
He's viewing the parameter as we use it in the US market.
Are you suggesting the value is wrong because he isn't in the US? Does that parameter not work else where on the planet?

grcauto said:
The calculations are found here
OK, so plug in the numbers and show us how you get to 1.5 g/sec for a 1.4 engine at 860 RPM. Just use plausible values for any unknown variables. It should get you pretty close.

grcauto said:
but I just use the RoT of 1 g/sec per liter of displacement.
I think that's a rule of thumb that you just made up yourself though. Or you've misread it/misunderstood it.

grcauto said:
A 1L engine is very close to 1g/sec and a 6.5L will be close to 6.5g/sec. Just the way it is.
Just the way it is on whatever planet you might be living on perhaps. But it's not the way it is here in the real world.

To illustrate the point here is a screen shot from my scan tool showing the MAF on my 1.5 engine...when it's not even running :p
446500


And just to prove the OPs figure is in the ball park, here is my engine at idle :
446501


If I helped you fix it, why not...

Your support is greatly appreciated
 

·
Registered
Joined
·
6,808 Posts
Are you suggesting the value is wrong because he isn't in the US? Does that parameter not work else where on the planet?

I suggest he gets a scan tool that provides accurate info. His is WRONG. So is yours.



OK, so plug in the numbers and show us how you get to 1.5 g/sec for a 1.4 engine at 860 RPM. Just use plausible values for any unknown variables. It should get you pretty close.


I think that's a rule of thumb that you just made up yourself though. Or you've misread it/misunderstood it.


Just the way it is on whatever planet you might be living on perhaps. But it's not the way it is here in the real world.

To illustrate the point here is a screen shot from my scan tool showing the MAF on my 1.5 engine...when it's not even running :p
View attachment 446500

And just to prove the OPs figure is in the ball park, here is my engine at idle :
View attachment 446501

If I helped you fix it, why not...

Your support is greatly appreciated
Covert your g/sec and see what you get. Why doesn't it work?
 

·
Registered
Joined
·
18 Posts
Discussion Starter #17
as it stands now, it is around 10.5g/sec which is around 43kg/hr when i switch the conversion.

i dont think its the maf. i replaced the old one just to see the reading and it was the same 9/10g/sec. it could well be the egr valve. is an egr valve duty reading of near 50% normal?.

when this started the car would buck just as im about to pull away on a cold start. when i apply a little bit of revs it would level and the car drives fine. mpg is still the same around 60.
 

·
Registered
Drives : Nissan NV200 Flies : Rans S6ES
Joined
·
14,610 Posts
as it stands now, it is around 10.5g/sec which is around 43kg/hr when i switch the conversion.
That sound OK, to me at least, and pretty much matches what I recorded on my own engine earlier.
The MAF value in the freeze frame is obviously way too low. As I said, the EGR valve is the likely suspect that is causing that.

SamH79 said:
is an egr valve duty reading of near 50% normal?.
That means the valve is being commanded open by the ECM. If you check your MAF value when the valve duty is 50% you'll see that it drops quite a bit. The problem is it might be sticking open at that 50% position after the 50% duty command has been switched off. If that is happening the MAF code will be logged because the ECM is expecting the MAF value to rise again when the ECM commands the valve closed (duty of about 5% or thereabouts).

SamH79 said:
mpg is still the same around 60.
60MPG...lucky you.

If I helped you fix it, why not...

Your support is greatly appreciated
 
1 - 20 of 50 Posts
Top