adjusted the TPS 2 times and no dice Options

[jsayre914]

I have a 2.0 D-jet setup. The classic bucking at constant speed. I have disconnected the TPS and the car runs super smooth with no bucking at all. The board has been replaced with Dave's board. I have adjusted it as per the pelican article. I have searched and searched. I printed the picture out of what it should look like before you put the cover back on. My adjustment is perfect. My TPS is adjusted right where it should be BUT is still Bucking


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Can there be somthing eles wrong with a TPS other than the correct adjustment??


Should I get another TPS to try it?


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[Spoke]

The classic bucking at constant speed.

What is it in the TPS that causes bucking at constant speed?

I know it has a throttle closed switch to engage the idle circuit in the ECU. But in this case the throttle is open a bit and so the throttle closed switch should be open and out of the circuit.

Then there are the fingers and associated contact to sense if the throttle is moving in the open direction. I guess if this contact is not clean the resistance from the TPS could be changing with constant open throttle causing the ECU to add spurts of fuel through the injectors.

Is this contact clean and in good operating condition? Did you measure the resistance when opening the throttle? you should get zero-open-zero-open on one pole and open-zero-open-zero on the other pole.

[r_towle]

The classic bucking at constant speed.

What is it in the TPS that causes bucking at constant speed?

I know it has a throttle closed switch to engage the idle circuit in the ECU. But in this case the throttle is open a bit and so the throttle closed switch should be open and out of the circuit.

Then there are the fingers and associated contact to sense if the throttle is moving in the open direction. I guess if this contact is not clean the resistance from the TPS could be changing with constant open throttle causing the ECU to add spurts of fuel through the injectors.

Is this contact clean and in good operating condition? Did you measure the resistance when opening the throttle? you should get zero-open-zero-open on one pole and open-zero-open-zero on the other pole.

Take a look at the Tps switch...it has 20 or so different contact that the fingers ride along, this determines the fuel duration.
A loose finger or inconsistent contact will make the wcu go from position x to idle and back again...
Idle is a non contact area on the middle finger

That is how I figure it's doing it, but I am sure someone will correct me.