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Please somebody have an answer for me!!!!

  • Thread starter Thread starter Kdubslugga
  • Start date Start date Apr 15, 2010

Kdubslugga

Active Member
Jun 7, 2003
1,515
3
38
Akron, OH
Apr 15, 2010
#1
  • Apr 15, 2010
  • #1
Car was running perfect, I swapped out my Cobra Intake for a Systemax, my 95mm PMAS mass air meter for a DBX 97mm, swapped out my 42lb injectors for 50lb injectors, my stock FPR for a Kirban AFPR, car will not run now. The 1st mass air meter I got from Andrerson which was reading voltage on the PMS but for some reason was throwing a code 66 on the dash "missing mass air signal, and a code 2000 on the PMS which is also "missing mass air signal" I sent that back to Anderson, they verified it was bad, and they sent me a new one, installed that one, same problem, however this time no voltage on the PMS. I went to Summit Racing, picked up another DBX, same problem no voltage reading on the PMS. If I install my stock sensor it has voltage. Completly lost on what do now, anything helps!!!!!
 
P

Pontisteve

New Member
Nov 3, 2009
26
2
3
Florida
May 26, 2010
#2
  • May 26, 2010
  • #2
Kdubslugga said:
Car was running perfect, I swapped out my Cobra Intake for a Systemax, my 95mm PMAS mass air meter for a DBX 97mm, swapped out my 42lb injectors for 50lb injectors, my stock FPR for a Kirban AFPR, car will not run now. The 1st mass air meter I got from Andrerson which was reading voltage on the PMS but for some reason was throwing a code 66 on the dash "missing mass air signal, and a code 2000 on the PMS which is also "missing mass air signal" I sent that back to Anderson, they verified it was bad, and they sent me a new one, installed that one, same problem, however this time no voltage on the PMS. I went to Summit Racing, picked up another DBX, same problem no voltage reading on the PMS. If I install my stock sensor it has voltage. Completly lost on what do now, anything helps!!!!!
Click to expand...

Check to make sure you're getting the right voltage TO the mass air meter. Check the resistance from the ground wire to an engine or battery ground, to make sure the ground wire is good. Check resistance in all 3 wires between the PCM and the MAF, one wire at a time, if all else fails. You should have battery voltage going to the meter, a good ground (with hardly any resistance to another ground), and then a good signal coming out of the meter.

Using backprobe pins, use a multimeter on the signal out of the airflow meter on + and ground to the engine or battery on -. When you check the signal coming out of the airflow meter, it should be roughly zero when off, roughly 1 volt at idle, and the more power you're making, the more the voltage should go up. At WOT, it should be somewhere between 4 and 5 volts. Never more than 5 volts though, or you have the wrong meter.

This should tell you if you have a wiring problem or a meter problem. The main thing is testing power in, power out, and ground quality.

When the computer detects no signal from the airflow meter, it will go into "Load with Failed MAF" table in the ECU, which is sort of like a preprogrammed MAF value. With lots of changes done to the car (especially an aftermarket MAF), this table won't be correct any more, so the "limp mode" due to the MAF code will probably make the car run poorly.
 

CDQICKGT

New Member
Jan 25, 2006
229
0
0
fort hood, tx
Jun 3, 2010
#3
  • Jun 3, 2010
  • #3
Pontisteve said:
Check to make sure you're getting the right voltage TO the mass air meter. Check the resistance from the ground wire to an engine or battery ground, to make sure the ground wire is good. Check resistance in all 3 wires between the PCM and the MAF, one wire at a time, if all else fails. You should have battery voltage going to the meter, a good ground (with hardly any resistance to another ground), and then a good signal coming out of the meter.

Using backprobe pins, use a multimeter on the signal out of the airflow meter on + and ground to the engine or battery on -. When you check the signal coming out of the airflow meter, it should be roughly zero when off, roughly 1 volt at idle, and the more power you're making, the more the voltage should go up. At WOT, it should be somewhere between 4 and 5 volts. Never more than 5 volts though, or you have the wrong meter.

This should tell you if you have a wiring problem or a meter problem. The main thing is testing power in, power out, and ground quality.

When the computer detects no signal from the airflow meter, it will go into "Load with Failed MAF" table in the ECU, which is sort of like a preprogrammed MAF value. With lots of changes done to the car (especially an aftermarket MAF), this table won't be correct any more, so the "limp mode" due to the MAF code will probably make the car run poorly.
Click to expand...

Or you could do a search for "setting base idle" and fix it the right way.if memory serves me it goes...

1. start engine.
2. unplug idle air control valve
3. adjust idle screw to where engine will BARELY stay idleing.
4.turn engine off, plug in IAC.
5. varify TPS voltage .90-.99
6.start engine and verify timing.
7.leave battery unhooked 5 mins, reconect and allow ECM 20 mins to "relearn".
All that and your done! helped my cammed 89gt and 90gt out ALOT!
 
P

Pontisteve

New Member
Nov 3, 2009
26
2
3
Florida
Jun 4, 2010
#4
  • Jun 4, 2010
  • #4
CDQICKGT said:
Or you could do a search for "setting base idle" and fix it the right way.if memory serves me it goes...

1. start engine.
2. unplug idle air control valve
3. adjust idle screw to where engine will BARELY stay idleing.
4.turn engine off, plug in IAC.
5. varify TPS voltage .90-.99
6.start engine and verify timing.
7.leave battery unhooked 5 mins, reconect and allow ECM 20 mins to "relearn".
All that and your done! helped my cammed 89gt and 90gt out ALOT!
Click to expand...

What does re-centering the IAC have to do with MAF no-voltage codes?
 

Notchbck93

New Member
Dec 9, 2003
422
1
0
IL
Jun 4, 2010
#5
  • Jun 4, 2010
  • #5
Kdubslugga said:
Car was running perfect, I swapped out my Cobra Intake for a Systemax, my 95mm PMAS mass air meter for a DBX 97mm, swapped out my 42lb injectors for 50lb injectors, my stock FPR for a Kirban AFPR, car will not run now. The 1st mass air meter I got from Andrerson which was reading voltage on the PMS but for some reason was throwing a code 66 on the dash "missing mass air signal, and a code 2000 on the PMS which is also "missing mass air signal" I sent that back to Anderson, they verified it was bad, and they sent me a new one, installed that one, same problem, however this time no voltage on the PMS. I went to Summit Racing, picked up another DBX, same problem no voltage reading on the PMS. If I install my stock sensor it has voltage. Completly lost on what do now, anything helps!!!!!
Click to expand...

Can you plug your 95mm in and use the pms compensate maf mode to adjust from the 42's to 50?

Were the 50's low impedence?

To me it sounds like the DBX meters are crap. If you plugged your old one in and it shows voltage, the system is ok, the meter is crap.
 

CDQICKGT

New Member
Jan 25, 2006
229
0
0
fort hood, tx
Jun 6, 2010
#6
  • Jun 6, 2010
  • #6
Pontisteve said:
What does re-centering the IAC have to do with MAF no-voltage codes?
Click to expand...

LOL...WOW. I posted that and it ended up in this thread? My mistake probably cause i posted via iphone... sorry guys
 
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