Toyota TPS

[ransomnotes]

While at the pick n pull today I noticed that some Toyota TPS's are almost just like the one in my 78z. I picked up a couple and tried to fit one on an extra throttle body and it lined up perfect. Anyone try this swap? It's been too cold to work on the car much lately, but I'll be trying this out soon.

[Daeron]

Just be certain of a few things.. I would imagine that blue's tech tips page on atlanticZ's website would have the reference material, if not directly there on the page then in the EFI bible available for download there...

 

First off, make sure you get a Throttle Position Switch, not a Throttle Position Sensor. One is a pair of switches, one for "Idle" position, one for "WOT" position, and no contact on either indicates "Cruise" to the ECU. The TP Sensor is more like a volume knob, sending a variable signal indicating how far the throttle is open. Our L-jetronic system uses the older, switch type.

 

Second, make sure that the switch operates in the right direction. (Although some wiring changes *should* be sufficient to rectify this potential issue.)

 

Third, make sure the switch open/close points are relatively close to original.

 

If all that works then it ought to be A-OK.. theoretically you could replace the TPS with a two way switch run on the fly by the driver in the cabin and it would FUNCTION.. you just run the risk of going lean or rich when you fail to adjust the switch acccordingly.

[ransomnotes]

Yeah, I was going to check Blue's tips for any info as well. I feel like I have a pretty good understanding of the TPS after having problems with mine a while back. I did a lot of research on his site and in the FSM to get the problem fixed, but I will need a newer one eventually. It's just not in the greatest shape, and $5 a piece is a good deal if the Toyota's work. If not, then oh well...I tried.

 

One thing I noticed right off the bat was that the contacts are a bit more spread apart on the Toyota TPS than the stock Z one. Thats pretty much the only thing different that I can tell visually. And theoretically the contacts could be bent into the right positions for the Z. I'll just have to make sure they work in the right direction and give it a try I guess.

[naviathan]

If you're talking about the internal contacts that could be a good thing. So long as everything else lines up correctly and the WOT contact hits before you get full pedal travel it should work. The extra gap between the contacts could be good for economy. I've always been curious why Nissan made the Z TPS with such little travel between idle and WOT. Seems there's a sweet spot for cruising and anything under or over that is either idle or WOT. When my 77 was on the road I could feel when it hit that WOT switch because it would pull hard. It seemed that switch kicked in with just slight pressure off cruise position.

[Tony D]

These parts are almost universal in application. BMW AFM's are available that work great as AFMs on 3 liter conversions, TPS is TPS as long as the connector attaches and the contacts are good, most of the issues that arise are from pins in the wrong place on one make compared with another.

 

Having a pin removal tool makes moving your harness pins around super simple. I have grafted Toyota AFM connectors onto Z harnesses for years becuase they have gold plated contacts.... I have been a 'pin cannibal' from Toyota Supras for about as long.

 

Check out the Bosch stuff in Volvos/BMW/Mercedes as well, Tefzel insulated wires, much better rubber on the backside boots, quick release injector clips.

 

My personal favorite is the old BMW and VW TPS's...which literally are two old-fashioned MicroSwitches set up on brackets with a cam on the throttle shaft. They were FAR easier to adjust than the new-improved 'Combi Switch' in the little black box.

 

Those sealed microswitches were bulletproof in terms of function. And they lasted forever. Next time you find an old 68 VW Type 3 in the junkyard, check out the TPS setup, I'll lay money the switches still work flawlessly after 40 years! The only problem we ever had with them was when ham-fisted mechanics bent the brackets during careless maintenance. The MAP sensor on that car was the size of the small Rolling-Rock Shorty Cans! Manually calibrated as well... Ahhh, those were the days!

[Daeron]

Check out the Bosch stuff in Volvos/BMW/Mercedes as well, Tefzel insulated wires, much better rubber on the backside boots, quick release injector clips.

 

SHHHHHHHHHH!!!!!!!!!!!!!

[ransomnotes]

I'm a pick n pull junkie, and the last time I was there I loaded up on Volvo and Saab quick release connectors. Almost all of them ended up being super clean. I've already replaced a couple and need to finish all the others before I install my new injectors and rail.

I don't recall seeing any BMW's or VW's at the couple of yards I go to, but I'll keep my eye out now.

 

Well I tried out the Toyota TPS as is just to see what would happen. Once I pulled the old one off and mounted this one I realized that it's set up backwards. The pins are on the left side instead of the right. I was on my work break so I didn't have much time to fiddle with it, but as I predicted there is too much gap between pins. I had to mash it to get WOT. So I think with some adjustments I may get it to work. At least now I have a cover for my original TPS, and I gave it another good cleaning while it was out.