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rewire TPS?
Posted: March 16th, 2010, 2:11 am
by holeski
Can anyone tell me why you can't or why people don't just change the pig tail connection on the RENIX harness to match the HO TB TPS sensor? I understand the two function differently mechanically but how do they differ electrically?
Re: rewire TPS?
Posted: March 16th, 2010, 8:19 am
by Muad'Dib
IIRC, the sweep of the potentiometer is backwards compared to the HO. So the computer reads the signal given from it differently. If you were to put a HO one on; the computer wouldnt understand what to do with the information it is being given.
Re: rewire TPS?
Posted: March 16th, 2010, 10:23 am
by holeski
Thats what I would have guessed, but every book and FSM I have read no mater what year between 1987 to 2003 gives the same test for the TPS. Says it reads between 0.00 and 5.0 volts. Both are a 3 wire variable resistor that provides the computer a input voltage signal, just with a slightly different female pigtail. They both receive a approximately 5 volts(FSM words) Only difference I notice is the 87 should read approximately 0.08v at idle and the newer one aprox 0.26 at idle. But if the throttle body is truly so much bigger that should be fine since there is an increased amount of air moving though at idle then before.
Has anyone had to adjust there TPS values with there builds and if so to what?
Re: rewire TPS?
Posted: March 27th, 2010, 11:45 pm
by holeski
Plechtan wrote:Here is how the TPS works, It is just like any other TPS. The value of the resistor is generally not important, because they are only looking at the voltage. When the wiper is towards the 5 volt side, you have 5 volts, when it is towards the ground side than it is ov if it is in between it reads some voltage between 5V and Ov.
So long as when you are at idle you have the wiper to the proper end of the pot (0V or 5v, I am not sure which) then it should work ok. The only other issue would be if the pot is non linier. You can tell be measuring the resistance from one end to the wiper, check 0 deg, 22 deg, 45 deg 77 deg and 90 deg. The values should increase 25% each time. You can check the old tps vs the new TPS. I am suer someone on the board has both lying around and can check for you..
tps.jpg
http://www.jeepstrokers.com/forum/viewt ... f=15&t=903
Re: rewire TPS?
Posted: March 30th, 2010, 3:05 pm
by Muad'Dib
There is a lot more to that thread than what you just quoted .. so anyone coming across this should also read that thread.
With that being said it may depend on if you have a manual or an auto. With an auto, i dont think it can be done. Maybe with a manual?? Its hard to say...
I still stick with if it hasnt been done yet there has gotta be a reason why because if it were as simple as most people think it should be (myself included) then why hasnt it been tinkered with? Were all tinkerer's lol!
Go ahead and try it.. just dont fry your ECU!
Re: rewire TPS?
Posted: March 30th, 2010, 5:31 pm
by amcinstaller
Muad'Dib wrote:Go ahead and try it.. just dont fry your ECU!
or have an extra in case!
