tps?

[doberman_52]

I noticed yesterday that when I put the gas pedle down a little at about 15mph, it went up to about 25mph and then downshifted. and if i drop the pedal, it takes a few seconds before it downshifts. Could this possibly be the TPS?

[doberman_52]

Anyone? And how do you clean the tps?

[BNaylor]

Does your 3.3L have the throttle body (TBI) or the multi-port fuel injection system?

Normally cleaning a TPS doesn't do any good and does not require cleaning. However, you can check the input and output voltages at the electrical connector.

[doberman_52]

Mpfi

[BNaylor]

Originally Posted by doberman_52

Mpfi

Hard to say whether the TPS is causing your problem but this may help.

The Throttle Position Sensor (TPS) provides the control unit with information on throttle position, in order to determine injector pulse width and hence correct mixture. The TPS is connected to the throttle shaft on the throttle body and consists of as potentiometer with on end connected to a 5 volt source from the ECM and the other to ground. A third wire is connected to the ECM/PCM to measure the voltage output from the TPS which changes as the throttle valve angle is changed (accelerator pedal moves). At the closed throttle position, the output is low (approximately 0.4 volts); as the throttle valve opens, the output increases to a maximum 5 volts at Wide Open Throttle (WOT). The TPS can be misadjusted open, shorted, or loose and if it is out of adjustment, the idle quality or WOT performance may be poor. A loose TPS can cause intermittent bursts of fuel from the injectors and an unstable idle because the ECM/PCM thinks the throttle is moving. This should cause a trouble code to be set. Once a trouble code is set, the ECM/PCM will use a preset value for TPS and some vehicle performance may return.

[doberman_52]

What else could be causing my tranny to shift like that, to have that lag? I've also said before about my tranny shifting hard, likes to jerk a bit when it shifts.

[BNaylor]

The 4T60E and similar autotransaxles have a vacuum modulator to help control line pressure and shifting including firmness (soft/hard) and timing. So check the vacuum line to the modulator and for a bad/ruptured diaphragm.

[doberman_52]

Ok, where does the vacum line come off the block at? Would it be by the one that goes to the cruise control and MBC? And this could also be causing the weird sift times?

[BNaylor]

Vacuum source is normally off the throttle body or upper intake manifold. Look for the line that drops down towards the tranny and the modulator. Your autotransaxle may be the RPO code ME9 but it is very similar to the 4T60E (M13). Both have vacuum modulators.

[doberman_52]

Ok, I will check that before I leave for work.