RPM Jumping while Driving in 1990 Camry

[tigger263]

Hi,
I recently replaced the 02 sensor and the throttle body sensor in my 1990 camry due to a check engine light and a code 25/26. However, after replacing both of these the rpm's are now jumping up and down when I am driving. It typically happens when I reach about 1000 rpms regardless of the speed and the car starts to jerk when I ease my foot off the gas. Does anyone have any idea what could be wrong with it?

[white90dx]

Did you adjust the TPS after installing?

-Charlie

[tigger263]

Yes, it was adjusted so the voltage matched what was in the Haynes manual which was between 0.2 and 0.8 K ohms.

[white90dx]

Originally Posted by tigger263

Yes, it was adjusted so the voltage matched what was in the Haynes manual which was between 0.2 and 0.8 K ohms.

Voltage and resistance (ohms) are not the same thing - what was the procedure listed in the Haynes manual?

Do you have a 4-wire or 3-wire TPS?

-Charlie

[tigger263]

Oops, I meant resistance, sorry about that. It is a four wire tps. We attached the tps, turned it until it was in the right range on the ohmmeter for the fully closed position, then tightened the screws on the tps and reconnected the wire. We were going off a table from the book. We used the correct ohm range from the fully closed throttle position because we didn't have the feeler gauges to put the throttle in the other positions. Was this the correct way to do it?

[white90dx]

I'm not 100% sure on this, but I would suggest readjusting the TPS to make sure that the idle switch is closed when the throttle body is closed (well, almost closed). There is a chance that the problem is that the ECU thinks that the throttle body is still open, causing some low RPM fueling issues.

-Charlie