You all suspected my usage of PULSIN.

You were correct.

To determine whether to take control itself or let the radio receiver do its thing, my PIC must read the PWM code from the radio receiver channel 3. That PWM comes in only fifty times per second.

I was asking PULSIN to measure that pulse without setting an interrupt for when it sees a rising edge. What are the chances of my PULSIN moment (plus delay waiting according to pulsin_max) seeing something happening only 50 times per second. Answer, not good.

What are the chances of my PIC seeing that pulse when the radio transmitter is not powered? None whatsoever!

So: When testing my car up on blocks in my "lab" and not remembering to turn on my radio transmitter the poor thing spends 99% its time waiting for a pulse that never arrives.

Yep. Turn on the transmitter (even with channel 3 in the autonomous control position) and my SRF05 blinkers flash like crazy. They are being continuously triggered.

I still have a problem with response time, but it is not because the PIC is lacking sensor information.

Ken