Diagnosing Force Electronics

ljshein

Petty Officer 3rd Class
Joined
May 17, 2005
Messages
94
I learned a few new things this week and I thought I would share some of the experience.<br /><br />My 84 force 124 developed a misfire above idle. The faster you go, the worse the misfire. At first I thought is was fuel and I switched to a portable tank but the problem persisted. <br /><br />After checking the plugs and doing a compression and spark test I found everything normal. So, next step is test the stator, trigger and coil packs.<br /><br />I've worked for years on automotive engines but this was the first time getting this deep on this motor. The instructions I found specified a DVA meter. For those of you that don't know (I didn't know), a DVA meter measures peak voltage in a pulse generated system. A regular multi meter measures RMS voltage which is average across the peaks. This link give a good explanation of the voltage differences.<br /><br /> http://www.kpsec.freeuk.com/acdc.htm <br /><br />So, being the smartass I am, I decided to use a regular multimeter and use the formula on the link to convert it. Didn't hurt anything but didn't work either.<br /><br />Stevens electronics makes a DVA meter that costs $225. What I found on their web site is an adaptor for a regular multi meter that measures peak and it only costs $46. I spoke to them and they assure me it will produce the same results and they will sell it to me directly.<br /><br /> http://www.stevensinstrument.com/peak_dva.htm <br /><br />Turns out my problem was a wire grounding against the block due to being pinched behind the power pack but I learned a tremendous amount.<br /><br />Finding a low cost way to read DVA was invaluable.<br /><br />I hope this helps someone else along the way.<br /><br />Jeff
 

roscoe

Supreme Mariner
Joined
Oct 30, 2002
Messages
21,753
Re: Diagnosing Force Electronics

good info, thanks.
 

Snakeoleo

Cadet
Joined
Aug 6, 2005
Messages
9
Re: Diagnosing Force Electronics

I have to troubleshoot my electronics this weekend and contacted Stevens about their PVM and PVM adapter for DMMs. Very nice people. While searching also came across another source for a PVM. Price is about half of Stevens. Here's the link.<br /> http://www.maxrules.com/fixtools530.html <br />Also looks like it might be a good source for outboard help.<br />Rob
 

rodbolt

Supreme Mariner
Joined
Sep 1, 2003
Messages
20,066
Re: Diagnosing Force Electronics

the one merc sells is analog and costs less than 100 bucks. it is polarity sensitive but if you have to measure negative peaks just reverse the leads. I think mine cost 39 dollars but that was a few years ago. 1991 or so :) . I also have 2 stevens CD-77 and 2 ferret instruments eliminator tachs and a couple of standard DVM's. but one of the handiest gadgets is a Kv tester.
 
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