ECUs and Tuning Discuss Engine Management, Tuning, & Programming
Sponsored by:
Sponsored by:

MAF Question

 
Old 03-17-2019, 02:50 PM
  #1  
Newb
Thread Starter
 
Join Date: Mar 2019
Posts: 21
Total Cats: -2
Arrow MAF Question

Hello Guys, I have a small embarrassing question about my Car's MAF.

I have a 99 miata and i need my maf to work properly for my ECU (Ecumaster DET3). Short story about it: It's a ECU that can make a conversion from MAF -> MAP. I installed the MAP and cut the MAF wire going to the ECU, down (LG/B Wire colour (i guess)).

Now the problems.


With the MAF connected to the ECU, when i measure the voltage it's all alright ( 1.7v at IDLE -> 4.8V at full 7k RPM ). Now.. if i unplugg the wire from the old ecu and measure the voltage of the sensor it says 7.2 V. At this moment i thought that the wire is broken or something and i removed the MAF from the car.

My MAF has 3 wires, GND SIGNAL and 12V.

I added a battery to the GND AND +12v, all ok, and when i check the SIGNAL comming from the maf it says 7.2V. Even if i blow on it or put a fan on it, that damn thing does not change...

For my ecu to make the conversion i must have the maf working good outside the car becouse the MAF signall will enter in the ecu (DET3) and DET3 will output a given voltage to the original ECU.

The Question is WHY? why does my MAF have a good output only when connected to the OLD ECU ? What is simulating the ECU ? How can i make it work normal outside the car (not connected to the ECU).

I made a lot of research and i couldn't find a answer.


I want to make it work like this: MAF FORUM POST

Why that MAF is working outside the car and mine not. I guess my MAF is not broken becouse it would not start without it, and it's values are ok, i guess (car running good, maybe a little rich).


Thank you in advance and sorry for my language.

P.S. I don't want to change it unless it's truely broken and please don't tell me that the ECU will change IGNITION timing if i change the maf, the DET3 will handle it, i know this


I draw a scheme: MAF DRAW


*Could it be a frequency MAF ?

Last edited by radulepy; 03-17-2019 at 04:17 PM.
radulepy is offline  
Old 03-17-2019, 03:52 PM
  #2  
Newb
Thread Starter
 
Join Date: Mar 2019
Posts: 21
Total Cats: -2
Default

radulepy is offline  
Old 03-17-2019, 05:18 PM
  #3  
Moderator
iTrader: (12)
 
sixshooter's Avatar
 
Join Date: Nov 2008
Location: Tampa, Florida
Posts: 18,907
Total Cats: 2,364
Default

Joe Perez any idea?
sixshooter is offline  
Old 03-18-2019, 04:06 PM
  #4  
Newb
Thread Starter
 
Join Date: Mar 2019
Posts: 21
Total Cats: -2
Question

Originally Posted by sixshooter View Post
Joe Perez any idea?
I have here a photo of it. So i tried everything and now i am wondering if it is supposed to work like this or am i doing something wrong, or it's broken..? Help
* here i connected it to a +12v supply and the signal wire (middle) shows 7.2V

radulepy is offline  
Old 03-19-2019, 06:08 AM
  #5  
Junior Member
 
Join Date: Jun 2015
Location: VIC, Australia
Posts: 131
Total Cats: 17
Default

I found the same thing. I believe there is a pull-down resistor inside the ECU that scales the signal. Haven't tried it myself but someone mentioned that they did that to get it working on another forum. Was a 1k resistor from memory.
You could always probe the OEM ECU to work out if there is one and what the value is.
Barton is offline  
Old 03-19-2019, 06:16 AM
  #6  
Newb
Thread Starter
 
Join Date: Mar 2019
Posts: 21
Total Cats: -2
Default

Originally Posted by Barton View Post
I found the same thing. I believe there is a pull-down resistor inside the ECU that scales the signal. Haven't tried it myself but someone mentioned that they did that to get it working on another forum. Was a 1k resistor from memory.
You could always probe the OEM ECU to work out if there is one and what the value is.
So can you give me the forum post? Or how did he connect it? I want to make it work outisde the car.
Thank you.

*but the thing is that the 7.2v does not change and i know that a resistor it pulling out the voltage. But if for example i pull down the voltage from 7.2v to 1 or 2 it will not change if o blow air on it either. I guess.
radulepy is offline  
Old 03-19-2019, 06:26 AM
  #7  
Junior Member
 
Join Date: Jun 2015
Location: VIC, Australia
Posts: 131
Total Cats: 17
Default

Barton is offline  
Old 03-19-2019, 06:30 AM
  #8  
Newb
Thread Starter
 
Join Date: Mar 2019
Posts: 21
Total Cats: -2
Default


Damn, thank you very much. I will try this today.
Thanks a lot. I posted on the other forums and nobody knew anything about it.
Will return with feedback
radulepy is offline  
Old 03-19-2019, 02:54 PM
  #9  
Newb
Thread Starter
 
Join Date: Mar 2019
Posts: 21
Total Cats: -2
Thumbs up

Hello,

I've just tested, it works very good.
I don't know if the values are good, if anybody have a table with the voltage of the maf on a given RMP will be very nice for me.

Thank you again!
radulepy is offline  
 
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
Techsalvager
MEGAsquirt
21
02-13-2011 11:36 PM
Carthusiast
MSPNP
7
03-03-2010 11:12 AM
gsx1992
Miata parts for sale/trade
1
02-23-2009 07:12 PM
musanovic
E-Manage
1
10-20-2007 10:50 PM
cmr991
DIY Turbo Discussion
3
04-20-2007 12:43 PM


Thread Tools
Search this Thread
Quick Reply: MAF Question


Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.