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Dave Nova
Dave Nova, Buick Technician
Category: Buick
Satisfied Customers: 1808
Experience:  ASE Master Certification. GM World Class Certification
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1999 Buick park avenue: series II..accelerator..engine will rev

Customer Question

1999 Buick park avenue 3.8 series II will not start or idle unless accelerator is pressed slightly engine will rev but will not idle?
Submitted: 7 years ago.
Category: Buick
Expert:  Ricardo Hohl replied 7 years ago.

hi, did your battery when dead at any time before this happing?, is there an engine ligth on?

Customer: replied 7 years ago.
no engine light and battery ok far as I know started the car when I removed from garage and shut off just acted up when I went to start it a couple of hours later?
Expert:  Ricardo Hohl replied 7 years ago.

ok do you have any tools that you can use to check the idle air control motor ,also do you have a voltmeter?, also do you have any choke cleaner?.

Customer: replied 7 years ago.
I do have a volt meter and I think some carb cleaner maybe brake cleaner?
Expert:  Ricardo Hohl replied 7 years ago.
ok do you know were the tps sensor is located?
Customer: replied 7 years ago.

have never looked for it

Expert:  Ricardo Hohl replied 7 years ago.
ok let me look it up and send you a picture of it.
Customer: replied 7 years ago.
That would be great
Expert:  Ricardo Hohl replied 7 years ago.
ok i am sending you a picture of a tps removel do not remove just try to locate it on the engine it should be by the throtle.
Customer: replied 7 years ago.
This is my mothers car located in differnt town than I live I was planning on working on it after work on monday
Expert:  Ricardo Hohl replied 7 years ago.
ok no problem just let me know when you are back in town.
Customer: replied 7 years ago.
no comp. there any test info i can do when i am there to decide if tps is faulty
Customer: replied 7 years ago.

should I purchase a tps?

 

Expert:  Ricardo Hohl replied 7 years ago.
yes can you remove the sensor wire connector and with key to on position engine not running check for 4 to 5 volts on the connector side, then reconnect the sensor and with paper clips insert on the back of the connector of each wire and key on engine off, look for .45 volts on the wires half of one volts.then open the throttle all the way open that voltage should go up to 4.5 volts, can you do this? here i am sending you a little information on how it works , make sure you transfer this info to your files because it will erase by tomorrow ok. if it does just let me know i will send them to you again.
Description and Operation
Notes
Throttle Position Sensor
Notes

Throttle Position Sensor

The Throttle Position (TP) sensor (2) is a potentiometer connected to the throttle shaft on the throttle body. By monitoring the voltage on the signal line, the PCM calculates throttle position. As the throttle valve angle is changed (accelerator pedal moved), the TP sensor signal also changes. At a closed throttle position, the output of the TP sensor is low. As the throttle valve opens the TP sensor voltage increases so that at Wide Open Throttle (WOT) , the TP sensor voltage should be above 4 volts . The PCM calculates fuel delivery based on throttle valve angle (driver demand).

A broken or loose TP sensor may cause intermittent bursts of fuel from an injector and unstable idle because the PCM thinks the throttle is moving. A hard failure in the TP sensor 5 volts reference or signal circuits should set either a DTC P0122 or DTC P0123. A hard failure with the TP sensor ground circuit may set DTCs P0123 and P0117. Once a DTC is set, the PCM will use an artificial default value based on engine RPM and mass air flow for throttle position and some vehicle performance will return. A high idle may result when either DTC P0122 or DTC P0123 is set.

The PCM can detect intermittent TP sensor faults. DTC P1121 or DTC P1122 will set if an intermittent high or low circuit failure is being detected. The PCM can also detect a shifted TP sensor. The PCM monitors throttle position and compares the actual TP sensor reading to a predicted TP value calculated from engine speed. If the PCM detects an out of range condition, DTC P0121 will be set.

 

 


The Throttle Position (TP) sensor (2) is a potentiometer connected to the throttle shaft on the throttle body. By monitoring the voltage on the signal line, the PCM calculates throttle position. As the throttle valve angle is changed (accelerator pedal moved), the TP sensor signal also changes. At a closed throttle position, the output of the TP sensor is low. As the throttle valve opens the TP sensor voltage increases so that at Wide Open Throttle (WOT) , the TP sensor voltage should be above 4 volts . The PCM calculates fuel delivery based on throttle valve angle (driver demand).

A broken or loose TP sensor may cause intermittent bursts of fuel from an injector and unstable idle because the PCM thinks the throttle is moving. A hard failure in the TP sensor 5 volts reference or signal circuits should set either a DTC P0122 or DTC P0123. A hard failure with the TP sensor ground circuit may set DTCs P0123 and P0117. Once a DTC is set, the PCM will use an artificial default value based on engine RPM and mass air flow for throttle position and some vehicle performance will return. A high idle may result when either DTC P0122 or DTC P0123 is set.

The PCM can detect intermittent TP sensor faults. DTC P1121 or DTC P1122 will set if an intermittent high or low circuit failure is being detected. The PCM can also detect a shifted TP sensor. The PCM monitors throttle position and compares the actual TP sensor reading to a predicted TP value calculated from engine speed. If the PCM detects an out of range condition, DTC P0121 will be set.

 

Expert:  Ricardo Hohl replied 7 years ago.
no!, not yet, i just need to test it i am not targeting the tps yet is the idle air control valve that i am after.but we need to make sure the voltage on the tps is correct first.
Customer: replied 7 years ago.
what and how do I test and I will get back to you
Customer: replied 7 years ago.
sorry replied before pics
Expert:  Ricardo Hohl replied 7 years ago.

ok.

Customer: replied 7 years ago.
just checked wires and everything is good any other ideas?
Expert:  Ricardo Hohl replied 7 years ago.
ok do you have the voltmeter?