i put in my 91jspec TPS the other day. just put it in, plugged it in, and took the car out for a spin. PERFECT. i didn't adjust anything. i was talking with my friend who used to have an 87T2, and he said he thought the 89-91 TPS's were self adjusting. meaning the screw doesn't need turning, the ECU i guess sorts it out. is this true? from everyone else i talk to they still say you need to adjust the screw. my TPS screw has a nut on the end of it......any else have one? just curious...

 

The electronic piece itself isn't self adjusting, but if the linkage on the TB is adjusted right to begin with it should be fine.

 

They are self adjusting according to Dave. He said if everything works, dont **** with it

 

I was kinda drunk last night when I replied.

It is self adjusting to a point, so if your setting was correct in the first place it should be fine.

 

thanks for the replies. so if i got codes 12 and 18 (for low and high range tps)...would that mean the last TPS was totally shot? or that the adjustment was off?

 

The 89-91 TPS is self adjusting *after* being initially set when installed. This means you just set it once (to get it reasonably close) then you don't need to fiddle with it all the time as you would the earlier version. As always, RTFM (read the, um...factory manual).
--
Blake Qualley
Rotary Engine Illustrated

 

I like the other 'F' word better. :p

Erik, to test your TPS grab yourself a multimeter and set it to resistance. Now test the full range of resistance by opening the throttle all the way and then closing it. If there are any spikes then the TPS is shot, if the numbers increase and decrease smoothly then it's probably fine.

 

yeah, before i put in the new TPS, i tested the old one. it appeared way off. aren't you supposed to get 1 ohm or some **** at closed throttle...and then 4 or so when open? i forget the numbers, but instaed of 4 i got like 13 or something...but maybe i was testing it wrong. i tried to adjust the screw but it wouldn't budge (there was a nut on the end of it, that i couldn't move either)...thats why i was asking if anyone has a nut on the end of their screw. seems like all the tutorials NEVER say anything about a nut...just a screw that needs turning. i guess this jspec TSP is ok though...other than a high idle it revs up perfect and decelerates fine...


the only thing i can think of as to the old one going bad was when i took it out, two of the wires were frayed open and the insulated rubber coating was sliced. so maybe the heat from the IC as my 15 hour trip progressed caused the the wires to mess up even more. cause for the first 1.5 hours of driving it home, it was fine...then all of a sudden it would buck...and by the time i got home...it had like no power...

 

Okay, there seems to be some confusion. There are two basic tests. One is for adjustment, while the other is for proper resistance over the full range of operation. What Mykl suggested was the resistance test, which is very important to determine if the TPS is good or not. For this test, you unplug the TPS from the harness and check resistance over the range of operation. The TPS doen not even need to be on the engine, nor does the engine need to be warmed up or anything. The resistance should change smoothly as you move the plunger in an out. Do this for both plungers. The other test is what you do to initially set up the device. Here, you (1) warm up the engine, then shut it off, (2) hook two VOMs or two test lights to the TPS *test connector* (green, three pins, near the stock airbox), (3) turn the ignition to 'on' (don't actually start the car!), and (4) adjust the thottle shaft cam until the test connector indicates one lead having continuity to the ground lead and the other not having continuity to the ground lead. Using a pair of test lights, this would be having one bulb lit and the other not lit. If neither or both are lit, tighen or loosen the cam screw until one goes out or one turns on. The cam screw is on the end of the throttle shaft (not on the TPS) and basically adjusts the cam that presses in the plungers when the throttle opens. Once it is set correctly, the ECU will self-adjust thereafter. You might also want to disconnect the negative battery cable and step on the brakes to clear the stored engine codes and (I suspect) erase any stored memory of the previously misadjusted TPS. Then, take the car for a nice drive to get the ECU to learn and adjust to the reset TPS. Check for codes afterwards and, if none are found, you are probably good to go.
--
Blake Qualley
Rotary Engine Illustrated

 

Okay, you've lost me.

What is this cam screw you're talking about? It isn't the one for the fast idle cam is it? Is it the screw on the main throttle linkage?

 

No, it's the deal that presses in the TPS plunger. This is what you adjust when initially setting the TPS. There is a good illustration in the FSM, which *everyone* here should own. Right?
--
Blake Qualley
Rotary Engine Illustrated

 

Aaaaah, okay. Sorry about my momentary lapse in comprehension skills. I know exactly what you're talking about.

I don't have a check lamp, I usually set mine with a digital multimeter. I've found that if all the other linkages on the throttle body are adjusted correctly the best way to set it is to match the low range resistance with the high range resistance when it's at WOT.