Accelerates on its own!!

MAZDA TRUCK
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RCALZADILLA
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While driving, rpm at about 2500, press clutch to shift (up of down) engine stays revved up without pressing the accelerator pedal. RPMs come back down only when next gear is engaged or brake pedal is pressed hard and sudden.
Happens on and off when engine warmed up.
Gunning accelerator pedal doesn't bring down rpms.
Lubricated throttle shaft with WD40, in and out.

MAZDA B3000 1994, STANDARD TRANSMISSION
138,000 MILES.
No fault code or Check Engine lite.
Idle Air Conotrol Valve resistance good (10 ohms).
Vehicle well maintained by me since purachsed new.
Feb 9, 2007 at 1:58 PM
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MHPAUTOS
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Hi there,

This does sound strange, I had a customers car (toyota) that did this, but not as bad, i found that there was a huge build up of sticky fuel & carbon deposits behind the throttle butterfly, i used a good quality throttle body cleaner and fixed the problem, worth a try, but with out seeing this first hand, it's a sticky (no pun intended) one.

Good luck,

Mark (mhpautos)
Mar 16, 2007 at 4:52 AM
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RCALZADILLA
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Have fixed the problem:
Replaced the IAC (Idle Air Control).
raul
Mar 16, 2007 at 8:09 AM
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HELLCAT18
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I have the same problem in my '86 b2000(look at the engine siize and model number*b2000 has the 2.0* they match...) Check your oil and make sure that it's not leaking it. My engine will rev to 2 grand when sitting when it's low on oil...
Mar 30, 2007 at 6:37 AM
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SERVICE WRITER
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[quote:fd2f8027d5="HellCat18"]I have the same problem in my '86 b2000(look at the engine siize and model number*b2000 has the 2.0* they match...) Check your oil and make sure that it's not leaking it. My engine will rev to 2 grand when sitting when it's low on oil...[/quote:fd2f8027d5]


The problem was fixed.
Mar 30, 2007 at 6:22 PM