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TPS dissected

Posted: Sun May 09, 2010 2:25 am
by BSOD2600
I picked up a used throttle body from a local junk yard this weekend, with the intent to replace my failing throttle position sensor (TPS). After getting it home, I measured it per the FSM and found out that it had already failed and wasn't even close to spec -- ah well there goes $11.

I decided to see if I could take it apart to try and 'fix' it since I had nothing to loose.

First up, back of the butterfly plate. I assume this is the ring which everyone says NOT to clean off.
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TPS removed from the throttle body. After prying the left side a bit with a screw driver, it became apparent that it wasn't going to come apart. I then started to drill out the metal rods which were holding the right side together.
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Finally the cover was removed to reveal the internals. Pin 1 is at the top. When those two long thin wires connect, that's the idle switch.
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Under the disk are two spring steel feet which travel around a rheostat like path in the PCB.
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I sprayed the whole thing down with electronics cleaner and then reassembled. Still was way too far out of spec, so into the garbage it goes. Last week my stable idle was ~1200 rpm. This week its ~1325. *sigh* need to get this thing replaced next week!

Re: TPS dissected

Posted: Tue May 11, 2010 12:04 am
by Legacy777
Nice pictures. How far off was the resistance?

Re: TPS dissected

Posted: Tue May 11, 2010 5:29 am
by BSOD2600
Well for starters, before I tore it apart, pins 1 and 2 weren't making any contact regardless of the throttle butterfly position. Post-tear down, they would make contact, but then the distance between the stopper screw and 'Portion G' was like 3mm (spec is 0.7mm). "throttle sensor" resistances were within FSM ranges though. I decided it wasn't worth my while to bother installing something which was already questionable / out of spec. All screws still had factory white/red paint markings too.