TPS: would you buy used?

I think I've finally nailed down my 22RE problems to a throttle position sensor. I can get PepVanceZone brand ones, new, for about $63 on EBay or the same at Advance using online coupons.

Or I can get a used OEM Denso from what appears to be a reputable seller on EBay for About $29. Sensor reportedly has less than 50k miles.

Would you trust a used TPS? Are the aftermarket replacements OK or shoddy bomb casings filled with used pinball machine parts?

I would trust a used TPS that I have tested. Any way you can test it?

Through E-Bay? Not likely until it arrives at my door. Returnable, but with shipping and restocking fee, I'd be close to the cost of a new one.

Here's the one I'm looking at,

E-Bay TPS

Before you purchase this item be sure you have properly diagnosed your car's issue as we do not accept returns or issue refunds.

On the otherhand they have enough good feedback I'd gamble 35 dollars in savings on it.

I'm pretty sure I've found that the idle circuit is dead on the current TPS. I get infinity on the multimeter on the first idle circuit part of the test. The other prongs are within spec. I would have no problem spending double on a new one from Advance. I think I'm more concerned that the new one is crappily made and/or not durable.

I would go for a used Denso from a reputable eBayer over whatever playskool Chinese bullE36 M3 the chains are likely to sell you, especially at half the price.

I forget exactly what the TPS looks like, anyway you can crack it open and maybe fix it? I dab of solder is a hell of a lot cheaper (and faster) than either purchase option!

I don't think so. As I understand it, the strips inside run on resistance. I think solder may or may not give the correct ohms. The inside looks like this:

Rockauto? Usually has the cheapest name brand stuff.

Name brand parts or bust. I've been burnt too many times.

Well, looks like I'll give one of the used ones a try.

bernardgam wrote: I find we can also find some car sensor here: http://www.buychina.com/categories/sensor--2-50011859

Canoe.

OP: Yeah, I remember now, I think you're right, that doesn't look very serviceable. There are a few guys who part out Toyota 4x4's on eBay, you might check around and see if their return policies vary. I have had success with the two or three I've used.

The throttle position sensor is a potentiometer. The ECU sends a 5 volt reference signal to the TPS. a second wire provides a current path back to the ECU. As the throttle is opened the voltage gradually increases from the about 0.8 volts to a wide open voltage of over 4.

not sure if it helps- but the TPS in my Miata started to act up, and seeing the astronomical new prices, I tried cleaning mine.

Spraying into the area where the shaft goes into the housing, there's enough of a leak there (apparently) to allow electrical cleaner. I used a MAF cleaner, since it's a very mild chemical. Worked like a charm- I seem to think that was 3-5 years ago. Since I mosty drive at 70mph, I suspect something just got onto the point I spend the most time at, this cleaned it off, and walla. (my symptoms were pretty funny- it would constantly go into decel fuel shut off, thinking that I was off throttle... very irritating, but I could only speed up or slow down)

Give it a try.

The most common failure is wear of the carbon film. This usually results in improper voltage to the ECU. At the point where the worn area is encountered, a stumble or hesitation will occur.

iceracer wrote: The most common failure is wear of the carbon film. This usually results in improper voltage to the ECU. At the point where the worn area is encountered, a stumble or hesitation will occur.

Yes, that is indeed true. But why not try cleaning the part with a couple dollar bottle of electronics cleaner prior to making the call that the sensor is broken vs. just has a dirt spot?

Oh, and the type of symptom of the failure is very dependant on how the OEM uses the throttle. Say on my Miata, it's mostly used as an closed determination, so the fault manifested itself as DFSO. If the OEM uses it for something like transient fuel, then it's more likely to be a stumble on a tip in. On ETC cars, TPS failures look totally different (especially since there are generally 3 sensors).

But LOTs of problems can cause hesitations and stumbles.

For a TPS, I'd trust a used OEM at least as much as a new cheapo Chinese item.