1985 TOYOTA MR2 FUEL ISSUES

  • Tiny
  • wkrizan
  • 1985 Toyota MR2

Engine Mechanical problem
1985 Toyota MR2 4 cyl Two Wheel Drive Manual 130k miles

I am down to the last two possible problems with a fuel issue that I have been having. I have replaced the in tank fuel pump and a new in tank filter. EFI relay switch and fuses as well, along with a new external fuel filter. The only other thing that I can think of is the injectors or mass air flow sensor. How can I determine which of the two is actually the problem sense they both are outrageously expensive? Is there a test that a back yard mech. Can do to find out which of the two it is?

Monday, June 23rd, 2008 AT 3:03 PM

8 Answers

  • Tiny
  • Dr. Hagerty
  • Expert
  • 9,705 posts

What exactly is the issue you are attempting to resolve?

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Monday, June 23rd, 2008 AT 3:11 PM
  • Tiny
  • rasmataz
  • Member

If you're talking about No fuel to cylinders-inspect and test the circuit opening relay and MAF sensor-

When the MAF sensor grounds the Fc circuit of the COR this is when the fuel pump powers up-

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Monday, June 23rd, 2008 AT 3:15 PM
  • Tiny
  • wkrizan
  • Member

I am getting fuel, after replacing the EFI relay switch, fuel pump and filters. She now idles fine but when I put her in gear there is no power to even get out of the driveway. So that is the problem, she idles fine but in gear she is starving for fuel push the clutch back in and it returns to normal idle. That is why I was thinking injectors or mass air flow sensor, unless I am missing something?

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Monday, June 23rd, 2008 AT 5:01 PM
  • Tiny
  • rasmataz
  • Member

Inspect and test the throttle position sensor-

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Monday, June 23rd, 2008 AT 5:16 PM
  • Tiny
  • wkrizan
  • Member

Resistance reading for the TPS, throttle fully closed.2 throttle fully open 4.65 indicates bad TPS?

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Monday, June 23rd, 2008 AT 6:42 PM
  • Tiny
  • wkrizan
  • Member

Does anyone know if that is within specs?

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Wednesday, June 25th, 2008 AT 6:16 AM
  • Tiny
  • rasmataz
  • Member

Adjust the TPS


http://www.2carpros.com/forum/automotive_pictures/12900_mrtps1_1.jpg




http://www.2carpros.com/forum/automotive_pictures/12900_mrtps_1.jpg

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Wednesday, June 25th, 2008 AT 8:39 AM
  • Tiny
  • donutman1
  • Member

Does yours backfire through the intake? Does it do it all the time or intermittently?

I tried swapping MAFs and throttle bodies with known good units. That didn't do anything. Please let me know if you figure yours out and I will let you know if I figure mine out!

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Friday, July 11th, 2008 AT 1:52 AM

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