no spark on left bank of 1993 175 mercury e.f.i.

jay576

Recruit
Joined
Jul 27, 2011
Messages
5
Any kind of help would be great already made sure fuel system was o.k. which it is saw top voltage regulator that is mounted behind the metal plate that the ignition coils mount to looks burnt where you can see the underside where they put the protective silicone on the regulator you can see some blackness through the silicone was told in a previous post to disconnect the voltage regulators and see if problem goes away well it didn't so that's when I got out and hooked up my spark tester and had great blue spark on right cylinder bank and no spark at all on left cylinder bank heard it could be a switch box causing the problem but I want to be sure I heard all I need is a voltmeter and something called a D.V.A. adapter if so where can I get the d.v.a. adapter and where can I get the specs. For what readings I should get and which terminals to probe again the motor will start and run but very sluggish and no power thanks to all who respond you are greatly appreciated and one more thing when this happened the boat was running great I was at wide open throttle and all of a sudden it was like someone turned off a switch from running great wide open to barely going 10 miles an hour at full throttle thanks again...
 

j_martin

Admiral
Joined
Sep 22, 2006
Messages
7,474
Re: no spark on left bank of 1993 175 mercury e.f.i.

You lost a bank of spark. Could be a switchbox, or it could be the stator.

There are 2 wires to each switchbox from the stator. Swap the pairs of wires between the switchboxes, so that the pair that went to the back one now goes to the front, and vice versa.

If the spark moves to the other bank, the stator is bad.
If it stays the same,
Put the wires back where you found them.
Disconnect the jumper wire between the switchboxes. (white with black tracer I think)
If the spark stays the same, the obvious switch box is bad.
If the spark now comes to all 6, the "good" switchbox is bad.

hope it helps
john
 
Top