1982 TPS Question

[radioactivesob]

I went to set my TPS last night using the trusted paper-clip jumper method, and could only get a reading of 0.004V across the sensor regardless of the sensor's orientation.

Does this mean the thing is broken?

I've been having severe idling issues and hesitation.

Thanks for your help.

 

[shark454]

I bought a Collectors Edition years ago that had idling issues and hesitations. The short story is I cleaned every pin( male and female ) going to and coming from the computer. I cleaned the pc board edge connectors and tinned the copper to insure a good contact. The computer had been replaced( there was a rebuild sticker on it) This was was back in 86. The problem went away and never came back. I owned the car for years.

If the computer cannot see the signal from the sensors cleanly and correctly, how can it respond??

Ok I didn't answer your question, the sensor(s) might be bad, but first make sure the grounds and connections are good.

Hope this helps....good luck!

 

[radioactivesob]

Awesome, thanks for the info. The strange thing is that had just set the TPS a week earlier, but then things started acting up again... I'll start by checking the electrical connections although I hate trying to get the computer out of the battery compartment...

 

[shark454]

Awesome, thanks for the info. The strange thing is that had just set the TPS a week earlier, but then things started acting up again... I'll start by checking the electrical connections although I hate trying to get the computer out of the battery compartment...

It was the TPS signal into the computer that was bad for me. Cleaning the connections was a real PITA but it had to be done. That was the problem, contact corosion/dirt. Extracting the pins out of the connector was tough. I needed to make a special tool that I could slide into the connector to release the lock tab. Again it was worth it and only cost my time. Good luck.

 

[radioactivesob]

So, I have another general question, let's say, I pulled my computer from the car and the ground wire from the Spark Control Module was hanging free and unconnected to the module. Would that hurt the unit? Is there anyway to test it?

Because this is what I found once I pulled the computer.

 

[shark454]

You're probably ok. Reconnect the ground after you clean it. Are you sure it is a ground and should be connected?

 

[wishuwerehere82]

I went to set my TPS last night using the trusted paper-clip jumper method, and could only get a reading of 0.004V across the sensor regardless of the sensor's orientation.

Does this mean the thing is broken?

I've been having severe idling issues and hesitation.

Thanks for your help.

The TPS is a variable resistor or potentiometer. The center pin (pin 2)on the connector is the output of the potentiometer which varies the output voltage based on the TPS's position.
To check it, unplug the harness and connect an OHMMETER between the center pin on the TPS connector and one of the outside pins. as you open and close the throttlebody, the resistance will increase or decrease depending on which outside pin you use. If you switch the meter to the other outside pin, the resistance will be opposite of the first one. That is if it goes low to high opening the throttle on the lower pin( pin 3), it will go high to low on the upper pin (pin 1 ).

The total resistance between pins 1 and 3 is between 9 KOHM and 12 KOHM depending on how worn the TPS is.
So as you open the throttle you will get a sweep between 9-12 KOHMS and 0 OHMS between the outside pins and the center pin on the connector.
If you get an open (INFINITE OHMs) between pins 1 and 3, the resistor is broken inside. Or if your reistance jumps around as you check between pin 2 and either of the others, then the wiper contact inside the TPS is bad.

You should definately have +5V on the lower wire on the wire harness. I would suspect the ECM connections if you don't.

 

[radioactivesob]

Well,

Did some cleaning of connectors this weekend and she runs like a champ now. Thanks for the help guys.

 

[shark454]

Well,

Did some cleaning of connectors this weekend and she runs like a champ now. Thanks for the help guys.

I'm glad. BYW cleaning connections does wonders on an old pinball machine that doesn't run anymore.
Enjoy your new car!