I tried to set my TPS using the light method the other day. I could not get only one of the lights on using the adjustment screw. The only way i could get one on and the other off is if i ever so lightly press on the throttle. And i mean i BARELY have to press on the throttle at all. Now my question is could my throttle stop screw be a little out of adjustment so that the throttle is coming too far closed?

 

The throttle stops WILL affect where the TPS gets adjusted. What your problem is, I have no idea. Try backing the screw back out. There are actually 2 places on the TPS that the lights will go out. One is the right place.

 

so what you are saying is that regardles of where the throttle actually stops i should still be able to get one of the lights to go out?

 

Don't use the light method. Use the resistance method. So much more accurate.

 

Well Aaron I'm actually just going through all the methods trying to figure out the one that works the best for me. And my TPS is in bad need of adjustment I'm pretty sure so it couldnt hurt to adjust it 3 times. The light method seems to be the easiest so im starting with it. And now it seems I might have found another problem so I'm trying to fix it also. The original problem that I'm trying to fix is my idle is all over the place....its usually really smooth but can range anywhere from 500-1200RPMS and sometimes will drop to 300-400ish and be pretty rough. My gas mileage is also pretty damn bad. And i have alot of backfiring.Its an 88 TII BTW.

James

 

I personally consider the light method to be the "hardest" because it's so innacurate and touchy. The resistance method is dead on, everytime.

 

Ok well you know better than me thats for sure. Its raining and super shitty weather here in tennessee right now and no garage so i cant check it today. Do you know what wires i need to check?

 

I have an idea which ones but i just want to double check it looks in this pic like it is a B/R wire and then a multi colored green/white/red am i seeing that right?

http://fc3spro.com/TECH/HOWTO/TPS/tps4.jpg

 

Check this out: https://www.rx7club.com/showthread.p...hreadid=235007

 

Ok im going to give that a shot if the weather clears up today or tomorrow. thanks guys.

 

Also could the TPS cause the problem i listed and would it be save to spray some of the throttle body linkages with white lithium grease?

 

Sounds like a vacuum/BAC problem. 99% of the time, idle problems are vacuum related.

 

yeah i totally agree with that Aaron but just the way my idle is makes me think that it isnt a vac leak. Sometimes it will hold so steady at 750 its not even funny but then others it will hold steady at 900 all day then the next day it will idle at 1100 for half a day and then 800 the rest of the day. But they are always strong idles.

 

Hm, stuck thermowax?

 

Could the problem actually be that the engine is not fully HOT and the thermowax/fast idle cam is holding the throttle plates/shaft to the not fully closed position, therefore screwing up your adjustments? YES

Using lights: Fully HOT engine. Turn the TPS adjustment screw fully anti clockwise til it almost falls out. Now screw clockwise, slowly til the first light comes on. Now even slower, keep turning the screw clockwise slowly til both lights come on. Now even slower, turn the screw anti clockwise til only one light is on. DONE, THROUGH, FINI.

Now if you have a series four, backprobe the green/red wire on the TPS plug and you'll see you have .....one volt plus or minus .05. Been there, done that. Same results each and every time using the light method and getting a one volt result as the output of the TPS.

One more time: FULLY HOT ENGINE. And no dilly dallying around setting the TPS!

 

Hey now the engine was fully hot...i had just finished running 90mph against a friend of mine on the way back to my house. when i got to my house i let it idle for about 2 minutes because i had been using alot of boost then i shut it off and promptly took off the intercooler and tried setting the TPS. the engine had been off maybe a full 3 minutes before i tested the TPS it shouldve ben fully warm still at that point right?? I wasnt dilly dallying either im trying my best, although i might not be the brightest bulb in the pack

 

And on another note...i dont think my thermowax is even engaging because i hardly ever get the fast idle on startup...maybe 1 out of every 100 starts does it actually do the fast idle.

 

I am going to add my voice to the choir here, and let you know that the light method has ALWAYS worked for me. Me and Aaron seem to differ on this point.

 

Brighter than the average bulb, I'm sure!

 

I agree with J-Rat, I've used all 3 methods of TPS adjusting, and noticed that the resistance and voltage methods will give you a tolerance of one full turn or more of the adjustment screw, whereas the light method (which I use 2 meters for) gets you within about 1/2 turn...I gotta admit, though, I didn't notice any difference in driveability using either methods...

 

well i think it will be cold but dry tomorrow...i will let you guys know the results....with both the ohms and light methods