Performance & Maintenance Engine, forced induction, intakes, exhausts, torque converters, transmissions, etc.

MAF doesn't work...wiring wrong?

Thread Tools
 
Search this Thread
 
Old 03-13-09, 10:26 PM
  #1  
ShiftPoint
Driver
Thread Starter
 
ShiftPoint's Avatar
 
Join Date: Dec 2003
Location: Texas
Posts: 160
Likes: 0
Received 0 Likes on 0 Posts
Default MAF doesn't work...wiring wrong?

ok. I have a 97 SC300 NA-T
previously running Emanage Blue with the auto tranny...worked great

I did a 5spd swap. got everything from a 96 SC300 shell. tranny, driveshaft, diff, MT ecu, etc...

swapped over to emanage ultimate, everything is setup correctly...

car wont idle with the 96 MT OBDII ecu. but it will idle perfectly and run with my 97 AT ecu.

the 96 uses the same 5 wire hotwire MAF as my 97, correct?

emanage ultimate readouts say that the MAF is spiking to ~5volts...
I'm trying to figure out if the MT ECU is bad or if there are MAF wiring differences between the 97 and the 96 or differences between MT and AT ECU's.

I have the the MAF wired up to pin 66b, thats how I had it wired when I was running my emanage blue.

thanks for any help
-Will
Old 03-13-09, 10:38 PM
  #2  
ShiftPoint
Driver
Thread Starter
 
ShiftPoint's Avatar
 
Join Date: Dec 2003
Location: Texas
Posts: 160
Likes: 0
Received 0 Likes on 0 Posts
Default

whenever I try to run the 96 ecu, I get a CEL.

I check the codes and it says problem with the MAF and something with the cam angle sensor...
Old 03-14-09, 05:50 AM
  #3  
sc-driver
Lexus Test Driver
iTrader: (7)
 
sc-driver's Avatar
 
Join Date: Oct 2006
Location: SoCal & SLOcal
Posts: 927
Likes: 0
Received 0 Likes on 0 Posts
Default

same here man. I tried hooking up my apexi neo to my 96 sc400 and it starts and then just stalls. Maybe there is a different kind of wiring going on with the 96, or maybe the ecu is going bad?

Did you get CEL P0100 (MAF Circuit Malfunction)?
Old 03-14-09, 08:04 AM
  #4  
ShiftPoint
Driver
Thread Starter
 
ShiftPoint's Avatar
 
Join Date: Dec 2003
Location: Texas
Posts: 160
Likes: 0
Received 0 Likes on 0 Posts
Default

yea...P0100

I read up on some threads about apexi afc installs on the 1996 model...I dont think they got it running right.

I'm going to try my ECU on my friends car to make sure its not the ECU.
Old 03-14-09, 10:47 AM
  #5  
StiCk3
Lexus Champion
iTrader: (5)
 
StiCk3's Avatar
 
Join Date: Oct 2006
Location: IN
Posts: 1,892
Likes: 0
Received 0 Likes on 0 Posts
Default

if you're having problems with the MT 96 ECU and have no problems with the 97 AT ECU why not just keep the 97 ECU and ditch the other one?
Old 03-14-09, 11:24 AM
  #6  
ShiftPoint
Driver
Thread Starter
 
ShiftPoint's Avatar
 
Join Date: Dec 2003
Location: Texas
Posts: 160
Likes: 0
Received 0 Likes on 0 Posts
Default

the AT ecu acts weird when I'm punching it and I change gears...its like it messes with timing and won't go anywhere once I gas it again.
Old 03-14-09, 02:15 PM
  #7  
sc-driver
Lexus Test Driver
iTrader: (7)
 
sc-driver's Avatar
 
Join Date: Oct 2006
Location: SoCal & SLOcal
Posts: 927
Likes: 0
Received 0 Likes on 0 Posts
Default

Originally Posted by ShiftPoint
yea...P0100

I read up on some threads about apexi afc installs on the 1996 model...I dont think they got it running right.

I'm going to try my ECU on my friends car to make sure its not the ECU.
aight keep me posted. It would be really weird if it was that the 96 had different wiring.
Old 03-14-09, 06:55 PM
  #8  
5sp_jzz30
Lexus Champion
iTrader: (2)
 
5sp_jzz30's Avatar
 
Join Date: Apr 2007
Location: IL
Posts: 3,560
Likes: 0
Received 6 Likes on 5 Posts
Default

you need an auto trans simulator for it to stop "acting" up.
Old 03-14-09, 07:47 PM
  #9  
ShiftPoint
Driver
Thread Starter
 
ShiftPoint's Avatar
 
Join Date: Dec 2003
Location: Texas
Posts: 160
Likes: 0
Received 0 Likes on 0 Posts
Default

yes, I'm aware of that. adding some resistors to make the CEL for the shift solenoids to go away.

some ppl have done that but still have problems with the AT ecu pulling timing

I have a MT ecu that came with my 5spd swap...I would like to use it.
Old 03-15-09, 01:54 AM
  #10  
5sp_jzz30
Lexus Champion
iTrader: (2)
 
5sp_jzz30's Avatar
 
Join Date: Apr 2007
Location: IL
Posts: 3,560
Likes: 0
Received 6 Likes on 5 Posts
Default

im not talking just resistors. contact dr. tweak. he can help you out.
Old 03-15-09, 08:48 AM
  #11  
ShiftPoint
Driver
Thread Starter
 
ShiftPoint's Avatar
 
Join Date: Dec 2003
Location: Texas
Posts: 160
Likes: 0
Received 0 Likes on 0 Posts
Default

ok, I just PM'd Dr Tweak.
Old 03-15-09, 10:28 PM
  #12  
ShiftPoint
Driver
Thread Starter
 
ShiftPoint's Avatar
 
Join Date: Dec 2003
Location: Texas
Posts: 160
Likes: 0
Received 0 Likes on 0 Posts
Default

i think I may have found the problem....

there are slight wiring differences between the 97 and 96.

when using the 96 ecu, I got 2 CEL's: one was for the MAF and the other was some code for the cam angle sensor. not sure why it said cam angle sensor since our motors dont have it....maybe my obd2 reader displayed it wrong. I cant remember the exact OBD2 code...p0100 was the maf

I'm cross referencing the 96's and the 97's wiring right now...I have already found out that my problems may be caused by 2 wires being in the wrong pin.

I'm going to swap the pins tomm and verify. hopefully everything works!
Old 03-15-09, 11:20 PM
  #13  
sc-driver
Lexus Test Driver
iTrader: (7)
 
sc-driver's Avatar
 
Join Date: Oct 2006
Location: SoCal & SLOcal
Posts: 927
Likes: 0
Received 0 Likes on 0 Posts
Default

Isn't the wiring for the 92-94 pin 66 for the maf as well?

thats really weird how the 1996 has a different wiring
Old 03-16-09, 08:33 AM
  #14  
ShiftPoint
Driver
Thread Starter
 
ShiftPoint's Avatar
 
Join Date: Dec 2003
Location: Texas
Posts: 160
Likes: 0
Received 0 Likes on 0 Posts
Default

ok this is what I found according to the wiring manuals....btw this is the differences for the sc300 96 and 97...not sure if its diff for sc400.

pin 66 is right. thats the maf signal wire.

the EVG is a dfferent pin...thats the ground for the MAF. pin 5 on the maf plug.
crank angle is diff pin
Fuel pressure upvalve (VSV) is diff
o2 heater
power steering pressure switch
Old 03-16-09, 08:56 AM
  #15  
ShiftPoint
Driver
Thread Starter
 
ShiftPoint's Avatar
 
Join Date: Dec 2003
Location: Texas
Posts: 160
Likes: 0
Received 0 Likes on 0 Posts
Default

i'm going to be moving wires today, I'll update later tonight.


Quick Reply: MAF doesn't work...wiring wrong?



All times are GMT -7. The time now is 04:59 PM.