Autosport Labs

philhoward · Post by **philhoward** » Sun May 11, 2008 2:40 pm

I have just installed a Megajolt on my 2lt Pinto, but am having problems getting a reading from the TPS when trying to calibrate it using software.

I have the following TPS
Ford PBT GF30
OTS 928F 98989
GA 4F29B

It is wired as follows
+5V to pin 1
Signal to pin 2
Ground to pin 3

I am getting the following voltages
5V between pin 1 and pin 3
2.57V between pin 1 and pin 2

Is the wiring wrong or would the TPS be faulty?

Any suggestions would be most appreciated.

Many thanks

MartinM · Post by **MartinM** » Sun May 11, 2008 4:52 pm

Do you mean you get those voltages whatever the rotation of the TPS?

philhoward · Post by **philhoward** » Sun May 11, 2008 5:12 pm

These are the voltages taken from the plug (not plugged into the TPS).
Can I test the TPS standalone without the powwer to it?

MartinM · Post by **MartinM** » Sun May 11, 2008 5:34 pm

The best thing is to measure the pin 2 voltage with the TPS connected - you should be getting something that changes with rotation, from 0V at one end of rotation to about 4V at the other end.

To check the TPS standalone, you need to be able to measure resistance using your multimeter. From your description of pin numbers, you should see a constant resistance whatever the rotation between pins 1 and 3 (maybe in the range 5K-50K) and a varying resistance between pins 1 and 2 with rotation - close to 0K at one end and close to the constant resistance you measured at the other end.

Report back with some more measurements....!

philhoward · Post by **philhoward** » Sun May 11, 2008 6:18 pm

Thanks Martin.

I will do some tests and report back. It may not be for a day or two due to work comitments

philhoward · Post by **philhoward** » Tue May 13, 2008 3:58 pm

After fiddling a few wires I am now getting a reading from the TPS and have managed to calibrate it. Readings attached

Phil