TPS Testing Options

[cabrioartie]

The car is a '74 2.0l, trying to fix all the items wrong after purchase.

Have found the following items bad and have replaced them:
- MPS
- AAR
- Decel Valve
- CHT
- Spark plugs and wires

I have a bogging/lack of power at about 3000 RPMs, I assumed it was the TPS. But, testing it with the 20 click method I get all 20 clicks consistently.

My question is, is this a valid test to ensure the TPS is good?

And if no, how else should I test it?

And if yes, what else could be wrong to cause the problem?

[bdstone914]

The car is a '74 2.0l, trying to fix all the items wrong after purchase.

Have found the following items bad and have replaced them:
- MPS
- AAR
- Decel Valve
- CHT
- Spark plugs and wires

I have a bogging/lack of power at about 3000 RPMs, I assumed it was the TPS. But, testing it with the 20 click method I get all 20 clicks consistently.

My question is, is this a valid test to ensure the TPS is good?

And if no, how else should I test it?

And if yes, what else could be wrong to cause the problem?

Pull the cover and inspect the traces on the circuit board. They can get worm. Sometins the arms can be bent to get the points to contact solid traces.

[emerygt350]

The clicks are a good method. If the TPS is shot you can get a complete cut at cruise or the loss of clicks. Is the bog you mention like a carb or does it feel like a complete engine wide miss?

[mgphoto]

The car is a '74 2.0l, trying to fix all the items wrong after purchase.

Have found the following items bad and have replaced them:
- MPS
- AAR
- Decel Valve
- CHT
- Spark plugs and wires

I have a bogging/lack of power at about 3000 RPMs, I assumed it was the TPS. But, testing it with the 20 click method I get all 20 clicks consistently.

My question is, is this a valid test to ensure the TPS is good?

And if no, how else should I test it?

And if yes, what else could be wrong to cause the problem?

I’ve found that the bog down at 3k is a distributor issue. Swooped in a 123 problem solved.

[cabrioartie]

The car is a '74 2.0l, trying to fix all the items wrong after purchase.

Have found the following items bad and have replaced them:
- MPS
- AAR
- Decel Valve
- CHT
- Spark plugs and wires

I have a bogging/lack of power at about 3000 RPMs, I assumed it was the TPS. But, testing it with the 20 click method I get all 20 clicks consistently.

My question is, is this a valid test to ensure the TPS is good?

And if no, how else should I test it?

And if yes, what else could be wrong to cause the problem?

Pull the cover and inspect the traces on the circuit board. They can get worm. Sometins the arms can be bent to get the points to contact solid traces.

Can the TPS cover be removed while the TPS is in the car? What would the procedure be? How do you remove the cover while the TPS is in the car?

[cabrioartie]

The clicks are a good method. If the TPS is shot you can get a complete cut at cruise or the loss of clicks. Is the bog you mention like a carb or does it feel like a complete engine wide miss?

Feels like a complete lack of power, and if I continue to push on the accelerator it eventually causes the car to jump forward/or feel like its accelerating, but it never feels like it has the proper power.

[cabrioartie]

The car is a '74 2.0l, trying to fix all the items wrong after purchase.

Have found the following items bad and have replaced them:
- MPS
- AAR
- Decel Valve
- CHT
- Spark plugs and wires

I have a bogging/lack of power at about 3000 RPMs, I assumed it was the TPS. But, testing it with the 20 click method I get all 20 clicks consistently.

My question is, is this a valid test to ensure the TPS is good?

And if no, how else should I test it?

And if yes, what else could be wrong to cause the problem?

I’ve found that the bog down at 3k is a distributor issue. Swooped in a 123 problem solved.

I actually purchased a 123 when I purchased the car, but I haven't thought about putting it in since I had so many other problems/failed components. I didn't want to change more than one thing at a time, but I've now replaced most of the failed items and could replace the distributor.

I was waiting on the 123 install until the car was running properly just in case the install didn't go well. Then I would know what was causing the problem.

[JeffBowlsby]

I was waiting on the 123 install until the car was running properly just in case the install didn't go well. Then I would know what was causing the problem.

This is astute. Bet you've done this before. (IMG:style_emoticons/default/beer.gif)

Agree with the above, the bogging down could be several things, even the items replaced if they are not 100% functional. However, have you lubed the advance weights in the dizzy shaft yet? They stick from time to time, and need 1-2 drops of 30wt or similar once a year to free them up. That might explain the hesitation, and if so is an easy fix. Oil goes in the hollow in the dizzy shaft after the rotor is removed to access it.

[emerygt350]

I had a brand new TPS board do that to me. There is a weird reaction where the ECU shuts off the injectors, I assume it has something to do with the decelerate function in the tps where it doesn't result in pulses when it backs down the board but I am not sure. I put in my old board and everything was great.

Definitely check those weights.

And yes you could leave the cover off but it won't help you figure out what is wrong. At least I can't imagine how it would. A noid light telling you if the injectors stopped firing while you are driving might.

[cabrioartie]

Is there a specific way to tell if the advance weights are stuck? I did add some oil to the distributor, but how would I know if they are working properly and moving freely?