TPS and Tranny cant get along under load!

[thegawd]

Pinger I was also think the same thing. I didn't quite know what I was looking at in the pics at first but it makes sense now to know this is a remote cable connection. not a bad idea. I agree that moving the connecting point into the center would absolutely give it more range of movement. maybe Tacosn already has?

 

[Pinger]

Pinger I was also think the same thing. I didn't quite know what I was looking at in the pics at first but it makes sense now to know this is a remote cable connection. not a bad idea. I agree that moving the connecting point into the center would absolutely give it more range of movement. maybe Tacosn already has?

If I've understood what's going on here - a carb conversion on a previously injected motor - then there's a need to match the radius of the arms/wheels of the throttle butterfly and the TPS to be exactly the same. As they would be when the TPS is directly on the throttle shaft. Re-establishing that if it has been lost is the first thing to do.

 

[TacosnBeer]

I think you need it to be able to output from 0.6V to circa 5V. That you only get 3.95V at WOT when it's set for 0.5V at idle implies the sensor isn't getting the full range of movement. If you could arrange for the cable attachment point to be closer to its pivot or, move the attachment point at the pedal end further from its pivot then it should be possible to get output between 0.6 and 5V over the pedal travel.

Are you getting sufficient travel at the pedal? If the radius where the cable attaches to the carb is different (smaller) from the throttle body it replaced then maybe not.

I have tried to move the cable around on the lever and it didn't increase the WOT voltage. I have full range of pedal as well as full WOT on the carb.

 

[TacosnBeer]

If I've understood what's going on here - a carb conversion on a previously injected motor - then there's a need to match the radius of the arms/wheels of the throttle butterfly and the TPS to be exactly the same. As they would be when the TPS is directly on the throttle shaft. Re-establishing that if it has been lost is the first thing to do.

Yes, the truck was originally a MPFI 305. The previous owner put in a 350 and converted it to carb before I purchased it. All the bugs haven't been worked out from the swap yet.

The TPS is the main drivability issue... fuel gauge was out, Speedo runs 10mph fast, A?C is all hooked up but I think the switch is bad as it doesn't light up at all or turn on.. lets see, what else is left... ABS sensor is acting weird when you first start the truck... etc etc. The truck sat for 5-6 years with the dead 305 in it before he bought it and swapped it.. its working out all the issues from sitting and the swap now. Other than that, its drivable.

 

[Pinger]

I have tried to move the cable around on the lever and it didn't increase the WOT voltage. I have full range of pedal as well as full WOT on the carb.

Can you arrange it to have 0.6V at idle position and 5V at WOT position? If not, it's out of synch with the throttle shaft.
The position of the outer cable mount will also influence things. One obvious departure from standard is that the cable doesn't roll around a wheel and maintain constant radius. If the throttle arm on the carb does, then it may be impossible to perfectly synch them.

 

[TacosnBeer]

This is the set up. I can get .6 at idle but, not 5v at WOT

I am gonna mess with it more today.

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[Pinger]

Can you post a photo of it exactly as it is configured re cable connection?

 

[TacosnBeer]

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[Pinger]

When you have been adjusting to obtain different output voltages, have you been shifting the hole the cable end enters or, adjusting the length/travel/position of the cable?

 

[TacosnBeer]

Mainly the position of the cable at the sensor. and the tension of the cable but not in conjunction with each other