Trottle Position Sensor Testing

[wawazat??]

Originally posted by Beav
Those midrange flaws are what condemn most sensors that we see in the shop. Even the boys at the dealer have to resort to it occasionally. It's just difficult for independants and owners to exercise that option....

Beav

Alright Beav, you threw this out there, now give up the rest. Where are you located and are you a Subaru Tech or do you work for another make? As you have seen already, we need the help!

[Beav]

Well I guess I shoulda done that to begin with. I've been a professional mechanic for thirty-one years, almost never for dealerships, and sold MAC Tools for a few years. I used to have a shop in Fla. years ago, but gave that up for more free time.

To be honest my Subie experience is small. I lived in Denver for a number of years, (a huge Subaru market) but mainly only did brake and suspension work on them there.

The main thing to remember is that theory generally applies across the board. Some cars have certain idiosyncracies (Chrysler A/T & A/C, Toyota oil leaks, anything British oil leaks - not to mention Lucas, the Duke of Darkness, electrical problems....) That's the best that boards like this have to offer - dealer mechanics work on so many of the same car that they often know what's wrong when the car pulls on the lot. As a group of owners you/we can share exploits and cures and hopefully save each other some money and grief. I see a lot of that happening here and without any of the backbiting that so often plagues most boards. This is a truly nice place to visit because of the contributors.

Anyway...I'm going to say this from the onset, I like to help but have limited time and limited experience with Subies. If I happen to see something that I can contribute to I'll toss in a comment. Please don't think that I'm trying to be a fathead when I do, I'm just tossing out an idea.... Hopefully Eddycat and Chris will be up to speed soon to help with their Subaru experience.

I had quadruple bypass surgery last month and I'm on the mend. That's the reason I have a bit more time to be here at present but those days are quickly waning - a mixed bag, nice to be recuperating so well, but that means going back to work sooner...

Beav

[Aredubjay]

Beav,
Any and all help you have to offer is greatly appreciated. And, as much as we don't want you to spend less time here, we hope your recovery is quick and complete. Don't forget us after you return to "The wide wide world of work." All the best!!

[svx_commuter]

Something else I have noticed on my car and I guess it is because the new TPS in place, is that the speed is a lot smoother at 65 MPH when the cruise control is on. I gues the old bad TPS was meesing up the cruise system.

[Beav]

I would think that the cruise works from a speed sensor in the trans. Normally TPS tells 'puter throttle angle so it can determine what the driver wants in relation to engine vacuum (load) and air flow/density in order to regulate injector pulse length. However you may be able to 'feel' more when you're more relaxed and in 'cruise'. TPS spikes can cause all kinds of weird problems. You should see some of the patterns they generate on the Fluke. It's a wonder some of them run at all...

[svxcuseme]

svx_commuter. Thank you! I am giving you a virtual high five !! Yes, I am some what of a dork!

Anyway, your test helped me diagnose my bad TPS. Thanks a ton. I had large consistent spikes in resistance followed by a large area of no change and some drops in resistance !!! I like knowing when stuff is broken before spending $180 to fix it !!!

[Electrophil]

Excellent write up!! I can spot a mechanical engineer a mile away. It's all those dog gone lab reports he had to do in college.

[svx_commuter]

Originally Posted by svxcuseme

svx_commuter. Thank you! I am giving you a virtual high five !! Yes, I am some what of a dork!

Anyway, your test helped me diagnose my bad TPS. Thanks a ton. I had large consistent spikes in resistance followed by a large area of no change and some drops in resistance !!! I like knowing when stuff is broken before spending $180 to fix it !!!

Thanks

It takes time to do the test and I agree it's an expensive item.

[svx_commuter]

Originally Posted by Electrophil

Excellent write up!! I can spot a mechanical engineer a mile away. It's all those dog gone lab reports he had to do in college.

Thanks again