Hey guys... I was messing around with my TB because I replaced the fast idle valve due to a looping idle. I also calibrated my TPS. It was reading .5 to 4.4v when I was calibrating it, TB off the manifold, throttle cable hooked up and TPS sensor plugged it. Once i bolted up the TB and burped the coolant system I noticed it was still acting weird.. also noticed that my idle screw was screwed in all the way.. I unscrewed it a little and the car started to idle perfect..

Now I rev it up a litttle to see if it would start surging again.. and yep it started again, a crazy surge. This is when i checked the TPS sensor again and I got only from .2v to 2.5 volts..

Whats going on? Everything is plugged in, why is my TPS reading 1/2 of what it used to all of a sudden?

Any help would be appreciated... thanks!

 

The only thing I could think of is that when you tightened up the adjustment bolts, your TPS moved slightly. While being as sensitive as it is, the voltage changed from this slight movement.

 

The problem is that when i move it around to adjust it the most i can get it to show is 3v.. and I tried a 2nd tps sensor which is doing the same thing.. Im thinking its something with the wiring now..

I will retrace my steps and hopefully figure it out..

 

The most is not what you should worry about, the least is what matters. >.45v-.5v is ideal

 

Sorry that wasnt very clear.. I meant the most at closed throttle.. with me just rotating the sensor..

This is pretty weird.. it just happend out of the blue.. can it have anything to do with the ecu?

 

recalibrate your TPS to read .5v @ closed throttle and 4.5v @ open throttle.

You can slightlly hit the TPS with a hammer so it will rotate in the direction you want it to read the right voltage.

DO NOT HIT IT TOO HARD OR YOU WILL BRAKE THE SENSOR.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 98ctr &raquo;</TD></TR><TR><TD CLASS="quote">recalibrate your TPS to read .5v @ closed throttle and 4.5v @ open throttle.

You can slightlly hit the TPS with a hammer so it will rotate in the direction you want it to read the right voltage.

DO NOT HIT IT TOO HARD OR YOU WILL BRAKE THE SENSOR. </TD></TR></TABLE>

I dont think you guys understand whats going on.. I know how to recalibrate the sensor.. I can move it from left to right all the way.. The problem is that all the way to the right (facing the firewall) the maximum voltage at closed throttle is .3v.. I cant get it to go to .45 unless i take the screws out and turn it past the holes...

I suspect the ECU because at one point it worked fine (yesterday morning) and 30 mins later after mounting the TB it started acting up... The TB plate moves freely through the full range..

Any ideas?

 

check your throttle body cable. or the sensor wires. 98ctr

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 98ctr &raquo;</TD></TR><TR><TD CLASS="quote">check your throttle body cable. or the sensor wires. 98ctr</TD></TR></TABLE>

I going to check the throttle cable because it started doing this after I tightened it, but it goes through the full range so I didnt suspect it.

I also have another ECU to test it with. So far i've tried 2 TPS sensors, tested the wiring to the TPS sensor and that was ok, but both TPS sensors do the same thing.

This is so aggravating.. one minute it worked fine then it just stopped.. damn electrical systems... lol

 

keep us updated, i would like to know what is wrong. good luck brother. 98ctr

 

I definately need the luck..

So i think i've narrowed it down to the wiring. So far i've tried 3 TPS sensors and 2 ECUs and they all do the same thing.

The throttle body moves in its full range (90 deg). From 0== to | facing the TPS hole. The bar is the little = groove that the TPS slider fits into.

Now im down to making new wiring for the TPS and the related sensors that connect to the same pins on the ECU. D11, D20 and D22.

Hopefully this will work but if it doesnt I'll have run out of ideas..

 

Have you measured the reference voltage by probing the two pins on the sides? You should see 5V.

 

The reference voltage is 4.9 volts.. Thats why its so confusing.. Everything checks out fine...

The TPS sensor sweeps from 0.0 to 5.1 volts or so when I slide it with my hand (off the TB) but when i put it on the TB it goes from 0.2 (max at closed) to 2.5v max at open.

Im sure Im putting it on the TB right because you just cant put it on wrong unless you try. And i've tried every way possible to put it on..

My voltmeter measures 12.5 v across the battery with the car off so its working correctly.

 

sorry to necro, only thread i could find, 92 honda prelude just recently is doing the same thing, replaced the tps and the max were getting is identical, .2 at closed and 3.51 at max throttle.