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Discussion Starter · #1 ·
Sup people!

So I have been in the process of building my 7MGE Turbo for the past few months now & I am Finally at the Running / Tuning stages.

After the build it started right up! But for some reason Will Not Run with the MAF / AFM Connected.....
What could be causing this!???

I have probed the diagnostic port & checked for codes. I am throwing Codes: 24, 31, and 41
Other than that If I try to start the car with the MAF / AFM Connected it will just stall & Die out.

I do not have an extra MAF / AFM lying around so I have NOT had the chance to test the MAF Sensor its self.
I have Bench Tested it and it seems to check out per the Cygnusx1 Manual. (Section=FI&P=94)
(I would post the link but Admin wont let me post links "Due to Spamming Reasons"...)

I have also Verified that the ISC Valve is Functioning as well as a Freshly Calibrated TPS, per the Cygnusx1 Manual.
ISC Valve: cygnusx1 (Section=FI&P=106)
TPS Calibration:
cygnusx1 (Section=FI&P=101)

Checking in to see if anyone had any input before I go out and buy new MAF / AFM to test.

...With all that being said hopefully its just a bad MAF / AFM.

Any suggestions / Comments or Insights would be Greatly Appreciated on My Quest for Boost!


I am also looking into a SAFC (APEXI) for now & Eventually a Fully Programmable ECU.

Any Advise with these Air Fuel Controllers / ECU's for this build would be greatly appreciated as well!

& On one last note I am a bit curios about Upgrading my MAF Sensor to the 7MGTE AFM.
The 7MGE MAF Connector has 7 Pins, While the 7MGTE has 5 Pins.

Is it Possible to convert with MAF / AFM the 7MGE Harness & ECU or would I be better off trying to find a 7MGTE Harness and ECU.
Or is there anyway to fit any other type MAF Sensor to handle the increase of air and decrease my headache? o_O


Little About The Build
1989 Supra Mark III
7MGE Engine

7MGE Parts:

  • Head, Cams & Block
  • Harness
  • ECU
  • MAF Sensor / AFM
  • Distributor
  • Igniter
7MGTE Parts:
  • Throttle Body
  • Intake Manifold
  • 3000 Intake Pipe
  • Intercooler Piping
  • Intercooler
  • Oil Cooler
  • Exhaust Manifold

Top End:
  • Fully Serviced Cylinder Head (Surfaced / Valves / Cams Etc..)
  • ARP Head Studs
  • FelPro Metal Head Gasket
Bottom End:
  • Block Surfaced
  • Cylinders Bored (.020)
  • Wiseco Forged Pistons (.020 Oversized) (Low compression)
  • Eagle H-Beam Connecting Rods
  • ARP Rod Bolts
  • ARP Main Studs (Align Honed Block)
  • Ground Crankshaft Rods & Mains (.010)
  • (Rotating Assembly Balanced)
  • *All New Gaskets & Seals

Other Parts:
  • Adjustable Fuel Pressure Regulator
  • Walbro 255 Fuel Pump
  • 650cc Fuel Injectors
  • New CT26 Turbo (Oil Feed & Return) (Have not Tapped into Coolant yet)
  • Divorced Turbo Down Pipe
  • Stage 3 Clutch
  • EGR Block-Off Plates
  • 3 Row Aluminum Radiator w/ Electric Fans
  • NGK Wires & Plugs 6282 (gap to .30)

Parts Needed:
  • Blow-Off Valve
  • WideBand 02 Sensor
  • Boost Controller
  • SAFC / Programmable ECU (Any Suggestions for a Reasonable Price?)
  • Anything Missing??? Let Me Know!!!
Im sure I left a few things out, but thats the gist.

Thanks!! o_O

1989 7MGTE Ice Blue Pearl,
59 Posts
Did you ever find the solution? My fresh rebuild is doing the same thing. Fires up with AFM connected but real choppy and will die out. Unplug AFM Idles like a dream. Have tested 3 other AFMs all with the same results.
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