1992 Buick Century Throttle Position Sensor issue.

LESPAUL5895

MEMBER
1992 BUICK CENTURY
6 CYL
FWD
AUTOMATIC
170,000 MILES

When I drove to work the other day my car seemed to run just fine with no issues. When I left work I got less than a mile down the road and noticed that my car was "sputtering" and jerking as if I was rapidly pressing and releasing the accelerator. After I stopped to see if I could see anything wrong with it I also noticed that it would run okay when it was stopped but when I let off the brake and started to accelerate it would stall. I've done some research and thought that it may be the throttle position sensor.

I went out to the local auto parts store and rented a code reader and it said that there was an issue with the Throttle Position Sensor being both too high and too low (codes 16 and 22). It also output a code 26 which is a QDM Fault it says. I'm not sure if this would also cause the problem.

My main issue at this point is that the clearance to remove the screws from the TPS is around 1 inch therefore I cannot get a screwdriver in there to remove them. The piece causing the issue with clearance is the thermostat housing which took me around 4 hours to remove the last time I replaced it due to other clearance issues. Is there any kind of tips that I may try to remove the screws with such low clearance without removing the thermostat housing again?

1 Reply

JDL

MECHANIC
16,098 POSTS

Did you look at the sensor signal. What is it reading, I'm just curious? At the throttle position sensor, the dark blue wire is signal, just turn the key to on, no crank. Use a digital multimeter look at signal on that wire. Backprobe the connector or use a straight pin in the wire, take the reading off the pin. Work the throttle, see if voltage moves smoothly up and down. Key on voltage at that wire is around.33 to.46 volt without touching the pedal.

Sometimes I use a screwdriver bit, around an inch long, then use wrench or vicegrips on the bit. It just depends on what I run into.