Drive By Wire Problems
 

I am working on a 2004 RX-8 automatic and I am stumped with the throttle problem I am having. The car would randomly die while driving, usually while slowing to a stop. It would start again reluctantly, usually by pumping the throttle while cranking. I pulled it into the garage and pulled off the intake to check the throttle which is where I am stumped. When the key is first turned on the butterfly valve closes all of the way and moves back to approximately where it started, I assume this is normal to zero it. However, when the accelerator pedal is pressed there is no response at the throttle body until the pedal is at about 1/2 throttle. Almost immediately after the throttle begins to move it is already wide open. My fist step was to check all connections and clean them up. They all looked fine. Next I began checking output voltages from the APP sensor at the ECU. Both were within range and moved smoothly from the bottom up to the top. The TPS voltages also check out within range and sit solid at the bottom end of their range moving smoothly but quickly with the throttle opening. I have also checked all wires for open circuits and shorts. Any suggestions where I should go from here?

Thats normsl...until the car starts the throttle does that....

Good to know. All of my cars have a cable. I suppose I'll start with plugs wires and coils and see if that solves the stalling problem. I just checked the plugs and is has 4 leading plugs in it. The plugs and coils look newish but the wires are definitely older. Thanks for the reply.

4 leading plugs?! It should only have 2 leading and 2 trailing plugs...

It looks like a previous owner rotated the old leading plugs into the trailing position and only bought 2 new leading plugs. New plugs (the correct ones) wires and coils have been ordered.