my 91 na runs with no maf

mr2 newbie · 08-20-2009, 09:43 PM

Im new to the 5sfe. can it run with no maf or no mass air flow sensor if you will. the car was running fine would not like high speeds over 80mph the car would cut now it is doing it under stander driving i know that the maf controls the air fuel but i also know that it is not suppose to run with out one help out a new guy if you know anything i need to fix my car

Medusa · 08-20-2009, 09:48 PM

No you can not run without a MAF. Very much not.

Sounds like a fuel cut problem, except the stock turbo's usually hit it, not the N/A motors. Actually, I don't even know if the N/A motor has a fuel cut.

And the MAF doesn't control your air/fuel mix. The MAF only tells your ECM how much air is entering the engine. Now, if it is defective and telling your ECM that very little air or too much air is entering, the ECM might cut or enrich your fuel mixture to the point that it would cause hesitation.

And at what RPM's is this happening?

mr2 newbie · 08-21-2009, 06:41 PM

it happens at all rpms and my car will start and run with no maf i know its crazy sounding but it does do you know it this has a cps or a cam sensor i had the same thing happen to my gfs old car and that is what it was but that was obd2

Oteck · 08-21-2009, 06:47 PM

the 5sfe run on a MAP

mr2 newbie · 08-21-2009, 10:03 PM

so if my car has a bad map do you think it will run like that it feels like a spark cut not fuel.

mr2 newbie · 08-21-2009, 10:09 PM

Quote:

Originally Posted by Medusa

And the MAF doesn't control your air/fuel mix. The MAF only tells your ECM how much air is entering the engine. Now, if it is defective and telling your ECM that very little air or too much air is entering, the ECM might cut or enrich your fuel mixture to the point that it would cause hesitation.

the apexi safc is a piggy back that controls the air fuel like most piggy backs. It wires into the maf that will tell the ecu or ecm how much fuel to send so there for the maf does contral the air fuel

fvillota · 08-22-2009, 12:16 AM

Quote:

Originally Posted by mr2 newbie

the apexi safc is a piggy back that controls the air fuel like most piggy backs. It wires into the maf that will tell the ecu or ecm how much fuel to send so there for the maf does contral the air fuel

we dont use maf! we use map sensor!
if that still installable like that?

shimric · 08-22-2009, 01:57 PM

Quote:

Originally Posted by mr2 newbie

the apexi safc is a piggy back that controls the air fuel like most piggy backs. It wires into the maf that will tell the ecu or ecm how much fuel to send so there for the maf does contral the air fuel

The 5sfe does not use a MAF. It uses a MAP. No MAF is anywhere to be found, if there is one. Someone put it on for unknown retarded reasons.

Medusa · 08-26-2009, 10:11 AM

Now I feel like a dumbass lol.

I didn't even check to see if he said, and if I was replying, MAP or MAF. Thank you all who corrected me.

@mr2 newbie-you failed to mention, in your original post, that you had a SAFC. That could cause a problem if not set up properly. And again, the MAF/MAP does not directly control your air/fuel ratio. It just reads the amount of air entering your engine, and tells that to the ECU. Your ECU, from this signal a a few others, decides how much fuel to inject. I'm not an expert on piggybacks, I don't really know much about them, but I believe they manipulate the output voltage on the MAP, therefore sending the ECU a signal different from the actual reading, which would cause it to inject different amounts of fuel for a given amount of airflow.

mr2 newbie · 08-31-2009, 07:52 PM

thanks all you helped i found out that my clutch was broken into 2. now the car just idles high but is jerking any more

Medusa · 08-31-2009, 10:03 PM

^WUT

How did you drive with a clutch broken in two?

08-20-2009, 09:43 PM	#1 (permalink)
mr2 newbie No Skills Join Date: Aug 2009 Posts: 5 Thanks: 0 Thanked 0 Times in 0 Posts iTrader Rating: (0/0% )	my 91 na runs with no maf Im new to the 5sfe. can it run with no maf or no mass air flow sensor if you will. the car was running fine would not like high speeds over 80mph the car would cut now it is doing it under stander driving i know that the maf controls the air fuel but i also know that it is not suppose to run with out one help out a new guy if you know anything i need to fix my car

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08-20-2009, 09:48 PM	#2 (permalink)
Medusa Cage Fighter Join Date: Sep 2008 Location: Reno, NV Posts: 630 Thanks: 9 Thanked 10 Times in 10 Posts iTrader Rating: (0/0% )	No you can not run without a MAF. Very much not. Sounds like a fuel cut problem, except the stock turbo's usually hit it, not the N/A motors. Actually, I don't even know if the N/A motor has a fuel cut. And the MAF doesn't control your air/fuel mix. The MAF only tells your ECM how much air is entering the engine. Now, if it is defective and telling your ECM that very little air or too much air is entering, the ECM might cut or enrich your fuel mixture to the point that it would cause hesitation. And at what RPM's is this happening?

08-21-2009, 06:41 PM	#3 (permalink)
mr2 newbie No Skills Join Date: Aug 2009 Posts: 5 Thanks: 0 Thanked 0 Times in 0 Posts iTrader Rating: (0/0% )	it happens at all rpms and my car will start and run with no maf i know its crazy sounding but it does do you know it this has a cps or a cam sensor i had the same thing happen to my gfs old car and that is what it was but that was obd2

08-21-2009, 06:47 PM	#4 (permalink)
Oteck RAAAGE! Join Date: Aug 2005 Posts: 2,154 Thanks: 8 Thanked 60 Times in 57 Posts Blog Entries: 2 iTrader Rating: (3/100% )	the 5sfe run on a MAP

08-21-2009, 10:03 PM	#5 (permalink)
mr2 newbie No Skills Join Date: Aug 2009 Posts: 5 Thanks: 0 Thanked 0 Times in 0 Posts iTrader Rating: (0/0% )	so if my car has a bad map do you think it will run like that it feels like a spark cut not fuel.

08-26-2009, 10:11 AM	#9 (permalink)
Medusa Cage Fighter Join Date: Sep 2008 Location: Reno, NV Posts: 630 Thanks: 9 Thanked 10 Times in 10 Posts iTrader Rating: (0/0% )	Now I feel like a dumbass lol. I didn't even check to see if he said, and if I was replying, MAP or MAF. Thank you all who corrected me. @mr2 newbie-you failed to mention, in your original post, that you had a SAFC. That could cause a problem if not set up properly. And again, the MAF/MAP does not directly control your air/fuel ratio. It just reads the amount of air entering your engine, and tells that to the ECU. Your ECU, from this signal a a few others, decides how much fuel to inject. I'm not an expert on piggybacks, I don't really know much about them, but I believe they manipulate the output voltage on the MAP, therefore sending the ECU a signal different from the actual reading, which would cause it to inject different amounts of fuel for a given amount of airflow.

08-31-2009, 07:52 PM	#10 (permalink)
mr2 newbie No Skills Join Date: Aug 2009 Posts: 5 Thanks: 0 Thanked 0 Times in 0 Posts iTrader Rating: (0/0% )	thanks all you helped i found out that my clutch was broken into 2. now the car just idles high but is jerking any more

08-31-2009, 10:03 PM	#11 (permalink)
Medusa Cage Fighter Join Date: Sep 2008 Location: Reno, NV Posts: 630 Thanks: 9 Thanked 10 Times in 10 Posts iTrader Rating: (0/0% )	^WUT How did you drive with a clutch broken in two?