Im thinking I have TPS problems. No codes are set but based on the way it drives and descriptions of what others are going through make me suspect of it. They report a dead zone of performance, which I have after it warms up from idle to about 2000 rpms. They also report a high idle for a few seconds, mine is 1400rpms, it would stay there unless I give it gas then it will drop. If it were a vacuum leak, wouldn't this happen every time?

Now my questions are: Is the TPS ignored in open loop, when the engine is cold from sitting overnight? If the engine is cold, its hard to start, but performance is great for the first few moments until it warms up, then it won't so much as spin the tires from a stop. It just has no power from idle to about 2000-2500 rpms. I can even foot break the gas and it won't break the tires loose at this point.

The SES light works, the ECM is about a year old, no codes are thrown.

People also say that the TPS can bet set within a range of .54 and .75. Is this true? Could a bad TPS not throw a code? I read people asking about the IAC along TPS problem threads too, and that just adds to the confusion. I know I need to get a voltmeter and figure this out, but I just wanted some imput from the gurus.

Thanks guys. -Kevin

 

TPS is not ignored during open loop. The TPS, among other things, affects asyncronous fuel injector pulses to compensate for throttle opening. A failed TPS will generally cause a hesitation on throttle tip in, followed by sudden acceleration as MAF enrichment catches up. TPS "glitches" or in range failures can cause drivability complaints without setting codes.

Proceed with sweep testing the TPS. You can use an analog volt meter or lab scope. If it tests okay, take a close look at the MAF sensor and CTS. Either of these could cause your complaint.