1985 Toyota MR2 Fuel Issues

1985 TOYOTA MR2
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WKRIZAN
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Engine Mechanical problem
1985 Toyota MR2 4 cyl Two Wheel Drive Manual 130k miles
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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?
Jun 23, 2008 at 3:03 PM
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DOCHAGERTY
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What exactly is the issue you are attempting to resolve?
Jun 23, 2008 at 3:11 PM
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RASMATAZ
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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-
Jun 23, 2008 at 3:15 PM
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WKRIZAN
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[quote:58b43c9d18="rasmataz"]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-[/quote:58b43c9d18]

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???
Jun 23, 2008 at 5:01 PM
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RASMATAZ
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Inspect and test the throttle position sensor-
Jun 23, 2008 at 5:16 PM
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WKRIZAN
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[quote:03cae2ebc5="rasmataz"]Inspect and test the throttle position sensor-[/quote:03cae2ebc5]

Resistance reading for the TPS, throttle fully closed .2 throttle fully open 4.65 indicates bad TPS?
Jun 23, 2008 at 6:42 PM
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WKRIZAN
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Does anyone know if that is within specs?
Jun 25, 2008 at 6:16 AM
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RASMATAZ
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Adjust the TPS


https://images.2carpros.com/forum/automotive_pictures/12900_mrtps1_1.jpg


https://images.2carpros.com/forum/automotive_pictures/12900_mrtps_1.jpg

Jun 25, 2008 at 8:39 AM
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DONUTMAN1
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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!
Jul 11, 2008 at 1:52 AM
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