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Re: yellow spark & miserable compression

To: triumphs@autox.team.net, libertyc <libertyc@erols.com>
Subject: Re: yellow spark & miserable compression
From: jim.sudduth@autodesk.com
Date: Wed, 24 Jul 96 11:27:34 PST
     Hi Carl:
     
     You describe symptoms of two different problems here:
     
     1. weak spark - this could cause plug fouling but would itself not be 
     caused by the other problems you mention such as bad compression etc. 
     How's your coil? I have a Lucas sport coil that I like. It produces a 
     fat, blue spark when I hold a plug lead near the head. Also check 
     points/condenser, rotor, cap, coil high-tension lead and swap out the 
     plug wires.
     
     2. you may have a couple of burned valves in #6 and #2 cylinders. I 
     was getting the same symptoms of frequent plug fouling in #6 cylinder 
     for about a year before the intake valve finally burned, compression 
     went down to 15 lbs. and a noticeable miss was felt. Is compression 
     lower in #6 and #2? Bad rings could cause low compression readings 
     across the board, loss of power and oil consumption but probably not a 
     miss in #6 and #2 unless those rings are *really* bad and the plugs 
     are way fouled. But then the car would probably smoke a lot. Does it? 
     
     I'd guess you can probably get away with just doing the head for now 
     and leave the rebuild until winter.
     
     Jim


______________________________ Reply Separator _________________________________
Subject: yellow spark & miserable compression
Author:  libertyc <libertyc@erols.com> at smtpcc1
Date:    7/24/96 12:06 AM


Hello Group - 
     
What color should the spark be by testing it with an extra spark plug and 
holding it near the block?  Mine is almost yellow/white with just a bit 
of blue near the tip.  I ask because I've never gotten the TR6 to run 
right.  It seems to be running on just 4 or 5 cylinders.  I can take the 
lead off numbers 6 and 2 and hear no difference in rpm or smoothness.  
     
Now keep in mind that my compression is rotten across the board (95-100), 
and my plugs are oily, (indicating rings, guides or valves bad?).
     
(I probably should have gone for a rebuild before doing the body work and 
paint job, but I had a bout with shipwright's disease this spring!)
     
Carl Huppert
75 TR6


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