TPS Help

Hello all,
I'm trying to help my father out, he's moving and has no internet access (think he's old gobbler or something here from WVa). He's asking for the prodcedure for properly setting the tps so it works corrrectly. He wants to set it back to stock position. when he pulls foot the accelerator, the engine dies on it's own.
he replaced it (TPS) and now it doesn't work.
there is a known vacuum leak, but he's looking into where that is right now.
In order to find the vacuum leak, he needs to get it to idle on it's own, ya know?

Thanks gents.

C

According to Mitchell OD5 and AllData the TPS is not adjustable. If the voltage readings are out of specs, it should be replaced.

kf_chris said:

Hello all,
I'm trying to help my father out, he's moving and has no internet access (think he's old gobbler or something here from WVa). He's asking for the prodcedure for properly setting the tps so it works corrrectly. He wants to set it back to stock position. when he pulls foot the accelerator, the engine dies on it's own.
he replaced it (TPS) and now it doesn't work.
there is a known vacuum leak, but he's looking into where that is right now.
In order to find the vacuum leak, he needs to get it to idle on it's own, ya know?

Thanks gents.

C

Click to expand...

Assuming it's a Renix (87-90), since later ones cannot be adjusted....

For an 87-90 4.0:

Test is done with throttle closed, connectors connected, ignition on, engine off. Insert probes through back of connectors to make readings. Use a high impedance meter. Adjust TPS by loosening mounting screws and turning in mount.

For manual connect + probe to terminal A, and - to B. Take a reading, which should be in vicinity of 5 volts but probably lower. Note the reading well. Now move the positive probe to terminal C. The reading should be 16 percent of the previous reading.

For Automatic, use the square, 4-terminal plug. Connect probe + to terminal A, and - to D. Note reading, which should be in vicinity of 5 volts. Now move probe + to terminal B. This reading should be 82 % of the first.

Click to expand...

For the Renix system, how and what does the adjustment do? In otherwords, if your voltage measurement is a bit high or low, will adjusting the TPS bring the voltage closer to spec somehow? If so, does turning the TPS one way or another retard or advance the voltage readings?

Electricity is not one of my strong points, so I'm not sure what a reading away from the 5 volts (or a varience from 82% for the second reading) is telling me.

Thank you Mr Currie, that's the info I was looking for. I'll make sure he gets it.

it's an 87 by the way. he lucked out and got the D44 we all want.

Hey pee weexj, I have mitchell on demand 5 (import and domestic )and it does have an adjustment precedure for the 4.0 liter mt and at. Its in the adjustment section or type tps in the seach feild.

desertred said:

For the Renix system, how and what does the adjustment do? In otherwords, if your voltage measurement is a bit high or low, will adjusting the TPS bring the voltage closer to spec somehow? If so, does turning the TPS one way or another retard or advance the voltage readings?

Electricity is not one of my strong points, so I'm not sure what a reading away from the 5 volts (or a varience from 82% for the second reading) is telling me.

Click to expand...

The initial reading of about 5 volts is usually something less, like around 4.6 or so. As long as it is in the neighborhood, it's all right. If it goes too far off, it's worthwhile checking wiring, connections and grounds. Some people have reported imroved readings and improved performance by adding a new, dedicated ground to the TPS. What really matters, though, is the percentage of that first voltage in the second reading. You must set it to 82 percent of the true base voltage, not 82 percent of 5.

The TPS itself is a variable resistor, like a volume control, which the throttle moves back and forth. The adjustment sets the starting point.

I really can't remember which way to turn it to change the voltage reading, but yes, adjusting it brings it to spec, and you just turn it until you get it right.

I'm also not entirely sure exactly what the adjustment does, other than to satisfy the specs. The one thing I noticed when playing with my 87 was that a second reading (the 82 percent one on an automatic) even a little too high seemed to affect off-idle throttle response and increased the tendency to spit or stall if you punched it.