TPS problems check it out.
10-28-2007, 10:34 AM
#1
TPS problems check it out. Ok. I have been having issues with this for a while now. I start my car while it's cold it runs fine. It warm up it goes into limp mode. We started looking at the scanner and the TPS sensor voltage was a little hight. We set it to factory specs and the percentage works.1-100%. But as soon as it gets too 100% it resets the persentage to 4% and stays there. Even if I open the throttle while it's running and rev it up. It has a new computor, New TPS sensor, all new MAF, MAP,O2's, new reflash, man, we cant figure this out. We thought the throttle body was causing this by going past 100%. they told me the Holley 58mm was junk and get something else. I refuse to beleive that. It was doing the same thing with the stock throttle body. Could the problem be in the harness....? Thats the last thing I have to replace. Anyone else had this problem?
It's a 1995 LT1 Z28. I know someone can help me.
It's a 1995 LT1 Z28. I know someone can help me.
11-02-2007, 11:44 PM
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sorry, I would have guessed it was going past 100% and back to zero too. To check that isn't it, use a scanner and bring it just up to 100% and see if there is any clearance between the throttle stop. Use a feeler guage or 2 if needed to stop the throttle blade. if it hits 100% and then jumps to 4% even with the throttle stop limited, then you definetely have an electrical problem. I would check the connector from the TPS sensor and from the pcm for corrosion or loose wires. If you still don't see it, leave the PCM and TPS sensor disconnected and use a DMM to check the resistance of all the wires that go between the 2. If you get high resistance, there is your problem. If not then I couldn't say what it might be.
Good Luck
Good Luck
11-03-2007, 09:51 AM
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Measure with a volt meter and make sure the TPS output doesn't exceed 4.5 volts when the throttle is wide open (even if it doesn't read quite 100% on the TPS% scanner). Adjust the bump stop and/or throttle cable to make sure the voltage doesn't go above that at WOT, and try that out...
If it's doing it after it warms up (i.e. transition to closed loop) there is probably some room left for fine-tweaking of your tune as well.
Rob (Bad30th)
If it's doing it after it warms up (i.e. transition to closed loop) there is probably some room left for fine-tweaking of your tune as well.
Rob (Bad30th)
