MAFs - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

chickenmanq · 11-25-2001, 10:40 PM

This may have been covered before, but who has mass airflow sensors for the ka24e, and how exactly does it work?  I know it pulls more air, but I thought the ECU would have the final say as to how much air gets by.

trashcan · 11-25-2001, 11:47 PM

MAF sensor doesn't pull in air, it just measures how much air is coming in.  The computer uses this and other sensors to determine how much fuel to inject.  

matic 240sx · 11-26-2001, 02:27 AM

man... got here to late.. heh..  trashcan is right...  and your car will not run without it... not long anyway

chickenmanq · 11-26-2001, 10:51 AM

Cool.  Thanks for the info.  Does anyone know where to get one, or are they retrofit items?  I couldn't find any on the internet, but maybe I'm not checking the right spots.  Anyone know how much they cost, too?

vancouvers14 · 11-26-2001, 11:09 AM

looking for a stock one (car-part.com) or an upgrade(mustang mafs should work)?

trashcan · 11-26-2001, 01:03 PM

Unless you have tested the Mustang MAF before, usually its not a good idea to just drop in a new air-flow sensor/meter (whatever).  This is pretty important since it helps determine how much fuel the injectors are going to squirt into your engine.  If the new one operates in a different voltage range than your old one, your either going to run very lean, or very rich.  Either way its not going to be pretty. So if you do get a new one, its going to be time to get a ROM tune at the same time.  But Mustangs aren't very common here, so maybe its a bolt-on part.

Patrick

chickenmanq · 11-26-2001, 01:29 PM

</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote </td></tr><tr><td id="QUOTE">Quote: from vancouvers14 on 11<img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/wow.gif" border="0" valign="absmiddle" alt=':0'>9 am on Nov. 26, 2001
looking for a stock one (car-part.com) or an upgrade(mustang mafs should work)?
</td></tr></table><span id='postcolor'>

Hey vancouvers14, do you know if the mustang mafs work, or are you guessing?  If so, does it retrofit easily?

vancouvers14 · 11-26-2001, 01:44 PM

i've heard of a bunch of 240s with them.  i'll try and dig up some more info...

vancouvers14 · 11-26-2001, 01:52 PM

ok, a cobra mustang or a z32 mafs will work, but you will have to re-program the ecu.  i'm pretty sure there's no mafs that you can just swap in and out

chickenmanq · 11-26-2001, 02:06 PM

####!  #### ####!  Couldn't they just make it easy for once.  So to reprogram the ECU, I'm gonna have to take it to someone like Jim Wolf, huh?

*drifterx* · 11-26-2001, 04:33 PM

listen to this... i dont have a clamp on my intake and my MAFS and sometimes it falls off and then my car would stall...........
i only had it happened on the highway 1 time and i got to the breakdown lane
i got the clamp now......

trashcan · 11-26-2001, 05:38 PM

You can take it to JWT, or you can get standalone engine management and reprogram it yourself, It might be expensive, but you if you do a lot of mods to your car (not just header, intake, exhaust) it'll be cheaper than getting it reprogrammed over & over.

Patrick

ca18Silvia · 11-28-2001, 07:48 PM

MAFs each have a diiferent curve of voltage output to airflow measured. Those that use voltage at all that is.

If you do not know the properties of the MAF you are replacing or the properties of the MAF you are replacing it with you are playing russian roulette with your engine.

The MAF is the ECUs PRIMARY sensor. This is not something to be kludged. Those who do either do not know better or do not have a choice.

chickenmanq · 11-28-2001, 08:01 PM

Yeah, I kinda got that impression.  I can imagine the engine trying to self destruct if it got the wrong signals.  I'm guessing an ECU upgrade will change that curve anyway, right?  Essentially making a bigger MAF not needed?  Thanks for the warning though.

misnomer · 11-29-2001, 02:46 AM

I don't imagine the MAFS is gonna give you any big speed boost till you get to the point that the factory one hits it's limit. It's simply a sensor, doesn't directly impact the vehicle's performance (untill the air flow is beyond it's range, at least <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/tounge.gif" border="0" valign="absmiddle" alt=':p'>)

ZeroGS14 · 11-29-2001, 05:04 AM

To run the mustang maf you have to have your ecu redone...I know JWT has a setup for that already...Jun can set up your ecu for a z32 maf..but I wouldnt worry about that until you are doing something major..ie...turbo

ca18Silvia · 11-29-2001, 04:45 PM

The only reason to change is seeing 5.2 volts on the multimeter you have on your MAF signal.

Most of the factory MAFs have a nominal air flow figure which they will top at. The for example Z32 is about 500hp worth.

This is all about the metering range. It has nothing to do with the size of the pipe. :-)

The JDM is full of tuners replacing MAFs with Z32s or R32s. The airflow improvement is only at the very top end. The extended metering range is the usual reason.

Hitting the fuel/airflow cut is not fun and depends on the fuelling and ECU spec of a given model. Your 240 models may have a better ceiling than some others.

My ca18 hits fuel/airflow cut at 9psi. Stock turbo with only minor efficiency improvements.

The Z32 AFM, PUMP, and large injectors are all necessary at this point. The factory cleverly specs all these levels to work out similarly. Once you max out one you are protected by the ECU from going too far wrong.

To change is a matter of altering the ECU parameters for the MAF and to suit the spec of the engine.

JWT as well as many others can do this job for you.

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11-25-2001, 10:40 PM	#1
chickenmanq Zilvia FREAK! Join Date: Nov 2001 Posts: 1,000 Trader Rating: (0) Feedback Score: 0 reviews	This may have been covered before, but who has mass airflow sensors for the ka24e, and how exactly does it work?  I know it pulls more air, but I thought the ECU would have the final say as to how much air gets by.

11-25-2001, 11:47 PM	#2
trashcan Leaky Injector Join Date: Nov 2001 Posts: 52 Trader Rating: (0) Feedback Score: 0 reviews	MAF sensor doesn't pull in air, it just measures how much air is coming in.  The computer uses this and other sensors to determine how much fuel to inject.

11-26-2001, 02:27 AM	#3
matic 240sx Join Date: Jul 2001 Location: las vegas Age: 42 Posts: 798 Trader Rating: (0) Rides Gallery: matic 240sx Feedback Score: 0 reviews	man... got here to late.. heh..  trashcan is right...  and your car will not run without it... not long anyway

11-26-2001, 10:51 AM	#4
chickenmanq Zilvia FREAK! Join Date: Nov 2001 Posts: 1,000 Trader Rating: (0) Feedback Score: 0 reviews	Cool.  Thanks for the info.  Does anyone know where to get one, or are they retrofit items?  I couldn't find any on the internet, but maybe I'm not checking the right spots.  Anyone know how much they cost, too?

11-26-2001, 11:09 AM	#5
vancouvers14 Zilvia Addict Join Date: Jul 2001 Posts: 868 Trader Rating: (0) Feedback Score: 0 reviews	looking for a stock one (car-part.com) or an upgrade(mustang mafs should work)?

11-26-2001, 01:03 PM	#6
trashcan Leaky Injector Join Date: Nov 2001 Posts: 52 Trader Rating: (0) Feedback Score: 0 reviews	Unless you have tested the Mustang MAF before, usually its not a good idea to just drop in a new air-flow sensor/meter (whatever).  This is pretty important since it helps determine how much fuel the injectors are going to squirt into your engine.  If the new one operates in a different voltage range than your old one, your either going to run very lean, or very rich.  Either way its not going to be pretty. So if you do get a new one, its going to be time to get a ROM tune at the same time.  But Mustangs aren't very common here, so maybe its a bolt-on part. Patrick

11-26-2001, 01:29 PM	#7
chickenmanq Zilvia FREAK! Join Date: Nov 2001 Posts: 1,000 Trader Rating: (0) Feedback Score: 0 reviews	</span><table border="0" align="center" width="95%" cellpadding="3" cellspacing="1"><tr><td>Quote </td></tr><tr><td id="QUOTE">Quote: from vancouvers14 on 11<img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/wow.gif" border="0" valign="absmiddle" alt=':0'>9 am on Nov. 26, 2001 looking for a stock one (car-part.com) or an upgrade(mustang mafs should work)? </td></tr></table><span id='postcolor'> Hey vancouvers14, do you know if the mustang mafs work, or are you guessing?  If so, does it retrofit easily?

11-26-2001, 01:44 PM	#8
vancouvers14 Zilvia Addict Join Date: Jul 2001 Posts: 868 Trader Rating: (0) Feedback Score: 0 reviews	i've heard of a bunch of 240s with them.  i'll try and dig up some more info...

11-26-2001, 01:52 PM	#9
vancouvers14 Zilvia Addict Join Date: Jul 2001 Posts: 868 Trader Rating: (0) Feedback Score: 0 reviews	ok, a cobra mustang or a z32 mafs will work, but you will have to re-program the ecu.  i'm pretty sure there's no mafs that you can just swap in and out

11-26-2001, 02:06 PM	#10
chickenmanq Zilvia FREAK! Join Date: Nov 2001 Posts: 1,000 Trader Rating: (0) Feedback Score: 0 reviews	####!  #### ####!  Couldn't they just make it easy for once.  So to reprogram the ECU, I'm gonna have to take it to someone like Jim Wolf, huh?

11-26-2001, 04:33 PM	#11
drifterx Premium Member Join Date: May 2001 Location: boston, ma Age: 44 Posts: 1,533 Trader Rating: (0) Feedback Score: 0 reviews	listen to this... i dont have a clamp on my intake and my MAFS and sometimes it falls off and then my car would stall........... i only had it happened on the highway 1 time and i got to the breakdown lane i got the clamp now......

11-26-2001, 05:38 PM	#12
trashcan Leaky Injector Join Date: Nov 2001 Posts: 52 Trader Rating: (0) Feedback Score: 0 reviews	You can take it to JWT, or you can get standalone engine management and reprogram it yourself, It might be expensive, but you if you do a lot of mods to your car (not just header, intake, exhaust) it'll be cheaper than getting it reprogrammed over & over. Patrick

11-28-2001, 07:48 PM	#13
ca18Silvia Join Date: Nov 2001 Posts: 4 Trader Rating: (0) Feedback Score: 0 reviews	MAFs each have a diiferent curve of voltage output to airflow measured. Those that use voltage at all that is. If you do not know the properties of the MAF you are replacing or the properties of the MAF you are replacing it with you are playing russian roulette with your engine. The MAF is the ECUs PRIMARY sensor. This is not something to be kludged. Those who do either do not know better or do not have a choice.

11-28-2001, 08:01 PM	#14
chickenmanq Zilvia FREAK! Join Date: Nov 2001 Posts: 1,000 Trader Rating: (0) Feedback Score: 0 reviews	Yeah, I kinda got that impression.  I can imagine the engine trying to self destruct if it got the wrong signals.  I'm guessing an ECU upgrade will change that curve anyway, right?  Essentially making a bigger MAF not needed?  Thanks for the warning though.

11-29-2001, 02:46 AM	#15
misnomer Nissanaholic! Join Date: Jul 2001 Location: Nevada Posts: 2,293 Trader Rating: (0) Feedback Score: 0 reviews	I don't imagine the MAFS is gonna give you any big speed boost till you get to the point that the factory one hits it's limit. It's simply a sensor, doesn't directly impact the vehicle's performance (untill the air flow is beyond it's range, at least <img src="http://www.zilvia.net/f/iB_html/non-cgi/emoticons/tounge.gif" border="0" valign="absmiddle" alt=':p'>)

11-29-2001, 05:04 AM	#16
ZeroGS14 Zilvia Member Join Date: Oct 2001 Posts: 181 Trader Rating: (0) Feedback Score: 0 reviews	To run the mustang maf you have to have your ecu redone...I know JWT has a setup for that already...Jun can set up your ecu for a z32 maf..but I wouldnt worry about that until you are doing something major..ie...turbo

11-29-2001, 04:45 PM	#17
ca18Silvia Join Date: Nov 2001 Posts: 4 Trader Rating: (0) Feedback Score: 0 reviews	The only reason to change is seeing 5.2 volts on the multimeter you have on your MAF signal. Most of the factory MAFs have a nominal air flow figure which they will top at. The for example Z32 is about 500hp worth. This is all about the metering range. It has nothing to do with the size of the pipe. :-) The JDM is full of tuners replacing MAFs with Z32s or R32s. The airflow improvement is only at the very top end. The extended metering range is the usual reason. Hitting the fuel/airflow cut is not fun and depends on the fuelling and ECU spec of a given model. Your 240 models may have a better ceiling than some others. My ca18 hits fuel/airflow cut at 9psi. Stock turbo with only minor efficiency improvements. The Z32 AFM, PUMP, and large injectors are all necessary at this point. The factory cleverly specs all these levels to work out similarly. Once you max out one you are protected by the ECU from going too far wrong. To change is a matter of altering the ECU parameters for the MAF and to suit the spec of the engine. JWT as well as many others can do this job for you.