After reading this post, I was prompted to order me on of those new fangled cheap Chinese hand held oscilloscopes.
( $69 with shipping ).
I was a CE with NCR for 40 years and always had a Tektronix handy, not so much anymore as I am now in database support.
Anyway, in cases like this it will be handy.
Also handy for measuring CPS output, injector duty cycle, camshaft position sensor etc......