THROTTLE CANNOT STAY STEADY AND GOES BETWEEN IDLE AND 2000 RPM

  • Tiny
  • pennettimom
  • 1988 Toyota Supra
  • 80,000 miles

1988 toyota supra - at 2000 rpm Have replaced air manifold meter and all hoses. Problem started after a hose burst. Car did not overheat. Replaced that hose and went ahead (due to age) replaced all hoses. When driving slowly (such as parking lots), car bucks badly at about 5-10mph/2000 rpm. Did some research and determined it might be the air manifold. Replaced that. Some improvement -bucking was not so prominent, but car cannot maintain steady rpm.

Have taken to four mechanics in the (DC) area, none have been able to figure it out. \ I just want to enjoy the car as I have for almost 24 years.

Saturday, January 28th, 2012 AT 9:38 PM

8 Answers

  • Tiny
  • rasmataz
  • Member

Carbuerator or EFI fuel system?

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Saturday, January 28th, 2012 AT 9:40 PM
  • Tiny
  • pennettimom
  • Member

Electronic fuel injection

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Saturday, January 28th, 2012 AT 10:00 PM
  • Tiny
  • rasmataz
  • Member

Clean and test the idle air control valve, EGR and PCV valves-also test the MAF and TPS sensor-to include a fuel pressure/vacuum leak-check-start here

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Saturday, January 28th, 2012 AT 11:02 PM
  • Tiny
  • pennettimom
  • Member

Thank you. I had thought something like this, but had no idea where to start. You've given me some starting points and I really appreciate it.

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Sunday, January 29th, 2012 AT 6:11 PM
  • Tiny
  • mhpautos
  • Expert
  • 29,860 posts

Does this model have a water heated throttle body?

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Sunday, January 29th, 2012 AT 11:48 PM
  • Tiny
  • pennettimom
  • Member

Truthfully, I'm sure what a water heated throttle body is, so I will say no. This is a 1988; maybe the 90's versions had it.

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Monday, January 30th, 2012 AT 2:34 AM
  • Tiny
  • rasmataz
  • Member

Have you checked what I've suggested?

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Monday, January 30th, 2012 AT 2:46 AM
  • Tiny
  • pennettimom
  • Member

No, it's winter here and my garage is not heated and I'm in the middle of renovating my kitchen. It will probably be two to four weeks before I can get through everything.

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Monday, January 30th, 2012 AT 5:27 AM

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