In the origional automotive application the dwellmeter was used to measure how long the points stayed closed as they were rapidly being opened and closed. This was a direct measurement of the gap when opened as a smaller gap meant it would be closed longer. In the Delorean we aren't reading "dwell". What you are actually reading is the pulse width of the ac signal going to the frequency valve. The larger the pulse width, (the longer it's on) the longer the frequency valve will remain open. Since the frequency valve is an on-off device the electric is in effect turned on and off rapidly to give the different amounts of fuel required. The more it is on the more fuel.Now you can see why we can use a dwell meter to read the signal to the frequency valve and why it is called such. By the way a rapidly changing dc voltage is in effect an ac voltage it just may not be sinosoidial, in this case it is a square wave which you would see if you scoped it. David Teitelbaum vin 10757 --- In dmcnews@xxxxxxxxxxx, "Dave Swingle" <dswingle@xxxx> wrote: > --- In dmcnews@xxxxxxxxxxx, "Dave Swingle" <dswingle@xxxx> wrote: > >they can be used to measure the "dwell" of the > >frequency valve as noted. The measurement number in this is not > >very meaningful, just an indication of working or not working. > > Should have said "dwell of the computer signal to the frequency valve". . . an indication of the **computer** working. . ". This does not test the valve itself. Original discussion in message 13001 > > Dave