Hey guys,

Does anyone know the values of the TPS resistors on the MSPnP daughtercard (90-93 ECU)?

I'm helping someone install a secondhand MSPnP, and it looks like the ECU was originally wired up for a variable TPS, so R6 and R7 are missing. But the car won't start as it's wired up, so I need to install those resistors (he has the original TPS).

Thanks in advance!
Justin

 

This is a Gen 1, right? If so, they were both 10K.

 

Yeah, it is. Thanks!

 

It's probably not the resistors; it's probably the jumper wires.

Test by simply unplugging the TPS and see if the car starts.

 

Yeah, you're right. We unplugged the TPS yesterday and the car started up, so I ended up just removing the jumpers and all was well. What are the resistors for? Just trying to decide whether it's worth putting them in or not.

Justin

 

The resistors stabilize the TPS reading because nothing is hooked up to the TPS input pin on the ECU. If you spend a lot of time with key on, engine off, eventually the TPS reading in the ECU will eventually creep up beyond the flood clear threshold, which will result in no-start if you crank. This can be fixed by power cycling the key. Or you can install the resistors. Or you can install a TPS.

 

Hi Ben, thank a lot for this information. I am just wondering about the TPS that why the TPS reading creep up beyond the flood clear threshold because its input is not connected to anywhere or there is some another reason? If the unconnected input is the reason then what is the logic behind it?

electronic pcb assembly

 

It's the nature of the hardware filtering when the signal input is floating.