What are the sure signs of TPS failure?

ned032002 · #1 03-27-2005, 03:25 AM

This is a similar question I know to what has already been asked in the past but still I am trying to diagnois my problem and the TPS (Throttle Postion Sensor).

As I said in another post, the problem that I am having is intermediate. Ok so I start the car and begin to leave my house when all of a sudden it seems like the car is running out of fuel (when in fact theres plenty). So I put the clutch in and I look at the RPMs and there at about 500-600 RPMs and the Check Engine light has come on as soon as the problem arrives. This happens so often I wish that the engine would just blow to rid me of the dilemma, but that would suck and I still would be mad. When I press in the Gas the engine seems to have a hard time gaining whatever its lost back, until I rev the hell out of it that's the only way to get the problem to go away until the RPMs settle.

I've changed the Fuel Filter, Plugs (gapped at .40), Wires, Coil Pack, Fuel Pump, Fuel Pressure Regulator, checked the Power Transistor for connection problems, and also I even removed the Fuel Cap incase the vent for the fuel tank was plugged some how.

I'm running out of ideas guys...I could really use some help. I know that this problem has been asked but I've searched this site but nothing was really helpful.

kjewer1 · #2 03-27-2005, 03:28 AM

TPS has very little to do with anything. The ECU doesnt even care where it is. It just looks for changes in throttle position to provide the accelerator pump function (dumps a little extra fuel when you first step on the gas, carbs do the same thing). I doubt it would cause much in the way of driveability issues, but I reserve the right to be wrong. It should be a pretty cheap part, why not just change it to (hopfully) rule it out?

ned032002 · #3 03-27-2005, 11:10 AM

Quote:

Originally Posted by 95 GSXracer

It should be a pretty cheap part, why not just change it to (hopfully) rule it out?

The problem is that I called Autozone and they said that they couldn't get the part and that I had to go straight throught the dealer. When I called the dealer they said that they could get it but it would be around $200. So I was hoping that it wasn't that cause I don't have that kind of cash to dump into a part that might not be the problem.

96spyderman · #4 03-27-2005, 01:50 PM

Could it possibly be the idle speed motor? I have posted about this possibly being the culprit before...
When I first got my car it started idling really low and it was carbon build-up in the idle speed motor area below the TB... My problem was from oil getting through the intake system and ended up at the ISmotor area sludging it up....
Just a thought....not sure if the N/T models are the same as the turbo models as for the throttle bodies?????

ned032002 · #5 03-27-2005, 09:40 PM

Quote:

Originally Posted by 96spyderman

Could it possibly be the idle speed motor?
Just a thought....not sure if the N/T models are the same as the turbo models as for the throttle bodies?????

Did your car have the same problem that I explained or was it similar?
Also I have considered this as a possible problem when I was looking through my repair manuel.

ned032002 · #6 03-28-2005, 02:07 PM

I was told that the possible failure of the ISC, IAC, or the Catalytic Converter would cause this problem but is that true?

Well I've been having some idle surging recently, so I was looking under the hood looking for maybe a vacuum leak or something. Well I noticed that on the Throttle body there was a cracked wire connection on top, I'm sure that some of you know what I'm talking about cause all of the 1g DSMs I've seen have the same bad cracked connector. I looked through my Chilton's Repair Manuel and I found a drawn picture of the Throttle body and related components (pg. 5-8), the picure points to connectors and the key says that there the "Connection for IAC motor connector and closed throttle position switch connector". I believe the one thats cracked it the IAC motor connector. When I unplug the connector the surging goes away and returns upon reconnecting, the surging happens only when the temperature of the car is at normal running temp.

Still trying to fix the problem if any of this tells anybody any thing to what my problem could be then please reply.

1stGenRocks · #7 03-28-2005, 09:16 PM

the cracked wire is usually the closed throttle position switch. is it just one single green wire?

if it is then all it does is tell the computer whether the throttle is shut. if it's shut then the computer controls the idle with the ISC (idle speed control) motor. check out VFAQ.com. they have a really good article on setting the idle on a dsm. It's actually much more complicated then most people think and if you do it wrong you get idle surge and stalling and other strange driveablity problems.

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