Throttle position switch (TPS) repair, Contact surfaces are worn Options

[Cevan]

I've completed my 1.8 to 2.0 motor swap and have my car running really good, except the TPS is worn right around the partially open throttle position.

I've cleaned the surface and the contacts with 2000 grit sandpaper and then used Deoxit electrial contact cleaner. This helped as it only hesitates/bucks at the barely open throttle position and cleared up the issue at positions further along the path of travel. I imagine that it's worn right at the spot where you're most often running at.

I searched but couldn't find any threads on repairing this. What I want to do is move the circuit board to the right or left, so that the contacts run on a fresh part of the board. Any ideas on how to separate the circuit board from the metal body and how best to reattach it? It looks like it may be soldered at the bottom right corner.

[McMark]

Using careful pressure, you can slightly bend the 'fingers' to run on a new area of the circuit board. No need to make it more complicated than that.

[Cevan]

Thanks McMark. I did as you suggested and gently pulled the contact arm out a little and got it to run on a new path just outside of the existing path. Put it all back together and reinstalled it, calibrated it and drove it. No more hesitation/bucking. Problem solved. (IMG:style_emoticons/default/smilie_pokal.gif)

[Derek Seymour]

I think this may have already been mentioned, but Otto is out of the new TPS's.

He instructed me to use a pencil eraser on the switch, which works really really well. The contact strips on mine are bright and shiny now and my bucking is gone.

However judging from the grooves I would venture to guess that I will need a new one eventually.

I was looking into using Eagle CAD to make a schematic and then exploring options for having them manufactured.

Is anyone else doing this? I don't want to jump in on a project that is already being done, nor do I want to compete with anyone.

Is there any interest from the community in having these made?

[rjames]

I think this may have already been mentioned, but Otto is out of the new TPS's.

He instructed me to use a pencil eraser on the switch, which works really really well. The contact strips on mine are bright and shiny now and my bucking is gone.

However judging from the grooves I would venture to guess that I will need a new one eventually.

I was looking into using Eagle CAD to make a schematic and then exploring options for having them manufactured.

Is anyone else doing this? I don't want to jump in on a project that is already being done, nor do I want to compete with anyone.

Is there any interest from the community in having these made?

There's always interest for repro parts. This part is a popular candidate. Of course it will always come down to how much they will co$t. (IMG:style_emoticons/default/smile.gif)

[Cevan]

I fixed mine in about 10 minutes, from start to finish. It should be good for another 50,000 miles or so. That fix might kill the market for this part.

[Derek Seymour]

It may kill it for some but for others I suspect that cleaning won't be enough. I just noticed a hestitation or two while driving at lunch 5 minutes ago. Not nearly as drastic as it was before, but still noticeable. It may have something to do with the deceleration fuel cut-off since mine is a '76 (IMG:style_emoticons/default/confused24.gif). But I'm guessing my TPS is just a little to worn in some spots.

Does anyone know what Otto was selling his units for? If it was somewhere between $150-$200 then it getting these made would be doable depending on the number produced at intial manufacture. SRP any less than that and it would be a loss.

[r_towle]

Isnt that gold?
Could gold leafbe applied tofix the groove?
Even silver solder might work?

Rich

[davesprinkle]

I have a board house manufacturing these circuit boards right now. I expect the shipment on 22 June 09.

[Derek Seymour]

I have a board house manufacturing these circuit boards right now. I expect the shipment on 22 June 09.

Awesome!!! Then I will drop the whole idea and buy one from you. Thanks for doing that!!!!!

[Pat Garvey]

The the original on my 72 was never as worn as yours, I puleld it for grins & used a jeweler's rouge cloth on it. Of course, you can't remove all of the groove, but it did clean up the groove & made better contact. Seems to work just fine - no bucks, etc.

I have a brand new one on the shelf, so there was so relief in knowing that if I screwed the original I could just slap on the new one.
Pat

[Gint]

Using careful pressure, you can slightly bend the 'fingers' to run on a new area of the circuit board. No need to make it more complicated than that.

Now that's a pretty simple damn solution (SDS get it?)!

[davesprinkle]

Circuit boards arrived. Here's a pic. Testing this week.

[davesprinkle]

More pics of initial board installation in this thread over on the club site.

[McMark]

(IMG:style_emoticons/default/dry.gif) Posting pictures here is apparently difficult.

[Katmanken]

Yeah, that's a really good picture on the other site...
It looks just like this.......

"This pic shows how the connector sits slightly higher due to the now-loose fit. (The connector should sit flush with the metal base.)

Attached File(s)
DSCN3982.JPG ( 722.59K ) Number of downloads: 3"

And It won't download....

[davesprinkle]

(IMG:style_emoticons/default/dry.gif) Posting pictures here is apparently difficult.

No, not difficult. Just frustrating. Two sites, same content, same users. It's easier to post a link than to redo the whole thread. Whatever, here ya go...

First, drill out the hole for the factory rivet to 3/32". The rivet hole in the new board is sized for a 3/32" pop rivet, which will be included with the board. For those who have forgotten what a drill-bit looks like, here is a pic:

[davesprinkle]

A business card makes a good ramp for getting the wipers onto the board.

[davesprinkle]

Here's a pic of the board with the business card removed. No rivet yet.

[davesprinkle]

Rivet installed. I would urge you to fend off the temptation to step up to a 1/8" diameter rivet. The larger head will short out the trace on the board. The correct rivet will be included with the board. Use it.