2001 Throttle Position Sensor????

[kmanxj5050]

Ok i blew a head gasket. Got it changed out and now the jeep wont start. kept trying and tryin and then got a check engine light. Hooked it up and it said tps low voltage (i think, pissed off and cleared it) tryed to start again and it still wont start.

My main question is would a bad tps not let the heep start?

thanks

 

[UNCC_99XJ]

Absolutely. TPS's can do a number of different things when they go south...high or low idle, hard starts, no starts..etc. The fact you pulled a code relating to the TPS pretty much narrows it down.

Try giving it just a little bit of gas while cranking and see what happens. Often times when they won't let the jeep start, it's because of an idle issue relating to that sensor. Most of the ones I see fail will not start or idle, but will start and stay running as long as you keep giving it gas.

 

[kmanxj5050]

tryed that litlle bit of gas wot dont matter. It is gettin alot of gas tho i push the purge in on the rail and alot came out. So idk maybe it is causin it to get to much gas?

 

[kastein]

Could be the TPS, could be the power supply rail that runs to the TPS and a bajillion other sensors, you could have nicked the wiring harness while working on the head. Measure the voltage at all 3 pins on the TPS with the key in run, one of them should read at or near 5 volts. If it does not you should start looking for damage on the wiring harness around the area you worked on.

 

[hubs97xj]

The fitting on the fuel rail will give you full pressure. Pressure at the rail does not mean you're getting fuel from the injectors. Test the TPS first, since you got a CEL for that.

 

[lawsoncl]

deleting duplicate

 

[lawsoncl]

You could try unplugging the tps sensor and see what happens. It should start without the tps plugged in, but run and accelerate poorly.

 

[gradon]

Did you have the head checked out real good or did you throw another HG on?

 

[birchlakeXJ]

If this TPS code came up IMMEDIATELY after changing the head and it wasn't there before, I'd certainly inspect the TPS wiring/connector for possible damage during the repair.

Testing the TPS with a manual and a meter isn't that difficult, and you could try unplugging the TPS as lawson mentioned.

The OBD system isn't perfect, but it generally leads you down the right road.

 

[kmanxj5050]

I checked the head fairly thoroughly my self but not profesionally. Just put another head gasket on. I just rebuilt the whole motor about 5,000 miles ago. I as putting the pushrods in and drop one down beside the lifter. Had to take the head back off to get it out (after it was torqued down dohhhh) and i am almost certain that that is what caused my head gasket to blow. seeing as i reused the already crushed one. And the head was completely gone through when i had the motor rebuilt.

i tried unplugging it and starting it and it still wouldn't i couldn't see any damage to the wiring either.

Also mine has 4 wires running to it not three.

I rarely do this but i am tempted to put the mfer on the trailer and haul it down to the repair shop

 

[hubs97xj]

4 wires? I'm pretty sure that's not the TPS.

 

[kmanxj5050]

oh ok the part i pulled out was toward the tappet cover, had the a black penis looking thing sticking out of it goin into the throttle body. I am just leaving work right now and i am gonna grab the electrical tester and go home and test it.

 

[winterbeater]

2000 FSM wiring shows orange 5V supply wire, brown/yellow ground, and orange/dark blue wire back to PCM which should show varying voltage with pedal position.

Maybe the part seeming to resemble your organ was the IAC.

 

[hubs97xj]

The four wire connection is the Idle Air Controller- it's on the inboard side. The other two sensors (MAP, on the outboard side; TPS on the rear) have three wires.

TPS on the left, MAP on the right

IAC (housing on the left, actual controller on the right)

You'll want an analog meter to check the "sweep" of the TPS if possible. (My DMM couldn't display the resistances quickly enough at least).

 

[kmanxj5050]

ok do you check the wires or the actual tps? i am assuming wires. i got the code again and it was high circuit p0123.

i just pulled the fuel rail and tried staring it and nothing came out the injectors????????

 

[winterbeater]

You probably need to back probe (paper clip jammed into the back of the plug or something similar) the orange/dark blue wire to check for the voltage coming out as you move the pedal.

If the PCM thinks the TPS is in full floored position, it does not run the injectors. This is to be able to clear flooded cylinders.

 

[kmanxj5050]

but i hit the purge and a ton of gas came out. Do the injectors open and close? or is it right that im not getting gas out of them?

im so extra lost it isnt even funny! plus i wanna go WHEELIN!!!!!!!

 

[hubs97xj]

You need to check the TPS. You have a CEL for the TPS malfunctioning. I typed p0123 into Google. Here's the first return.

What does that mean?

A P0123 code means that the the car's computer has detected that the TPS (throttle position sensor) is reporting too high a voltage.
OBD-Codes.com on Facebook
Symptoms
Symptoms may include:

* Rough idle
* High idle
* Surging
* other symptoms may also be present

Causes

A code P0123 may mean that one or more of the following has happened:

* TPS not mounted securely
* TPS circuit short to ground or another wire
* Faulty TPS
* Damaged computer (PCM)

Possible Solutions

If there are no symptoms, the simplest thing to do is to reset the code and see if it comes back.

If there are symptoms such as the engine is stumbling or hesitating, carefully inspect all wiring and connectors that lead to the TPS. More than likely the problem is with the TPS wiring. Check the voltage at the TPS (refer to a service manual for your vehicle for this specific information). If the voltage spikes or is too high (over 4.65 volts with key on, engine off), then that is indicative of a problem. Carefully trace each wire from the TPS wiring harness to check for breaks, rubbing against other components, etc.

The computer is saying your TPS is malfunctioning. This is not a fuel rail problem. It's very likely the sensor, or the wiring to it is damaged. If you search, the procedure for testing either has probably been posted on here numerous times.

<edit- didn't copy entire text>

 

[winterbeater]

but i hit the purge and a ton of gas came out. Do the injectors open and close? or is it right that im not getting gas out of them?

im so extra lost it isnt even funny! plus i wanna go WHEELIN!!!!!!!

If you were turning the motor over with the starter and had the throttle to the floor, gas SHOULD NOT have been coming out. If throttle was closed or only partially open, they should have been squirting gas.

 

[kmanxj5050]

it wasnt spittin gas closed open or partial throttle