ecu voltage problem

[Roy]

S. Lastuka wrote:
> 
> I am an FSAE student and we built an EFI computer for the competition.
> There seems to be a problem running it off the car's power supply, ie the
> battery.  When it is hooked up to the battery the computer holds pulse
> widths at around 1 ms per revoltution regardless of throttle position.
> When we hook it up to the standard voltage regulator used for testing in
> the lab the car works perfectly with full rpm and throttle range, but
> can't move because it is attached to an extension cord.  We're using a
> 68hc11 processor.  If anyone has had any weird voltage problems like this
> any help would be appreciated.  Thank you,
> Sean
>
>  GROUNDING, have you got a proper electronic ground and a power ground
>  the vehicle electrical system is very very noisy.